rwiederrich
Goldfinger
Reged: 11/17/05
Posts: 8334
Loc: Bremerton Washington
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A fellow member has asked me to assist him in the fabrication of his 1" X 12.5" plate glass blank into an f/6 mirror.
After a week or so of distraction...I tooled it up on the polisher and began grinding out the sagitta. Left to itself most of the day with a water drip..I cut the near 5mm sagittal depth. Here are some initial pics of the job being done on my porter polishing machine.
Rob
--------------------
www.goldmtobservingcenter.com
A great place for amateur astronomers, and ATM's to come and enjoy their hobby.
http://tech.groups.yahoo.com/group/HomemadeRefractorTelescopes/ My homemade refractor group.
www.vimeo.com/6014031
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rwiederrich
Goldfinger
Reged: 11/17/05
Posts: 8334
Loc: Bremerton Washington
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A bit closer view of the diamond blade doing its business.
--------------------
www.goldmtobservingcenter.com
A great place for amateur astronomers, and ATM's to come and enjoy their hobby.
http://tech.groups.yahoo.com/group/HomemadeRefractorTelescopes/ My homemade refractor group.
www.vimeo.com/6014031
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droid
rocketman
Reged: 08/29/04
Posts: 4046
Loc: ohio
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Wow thats so cool to see.....thats got my blood pumping again,lol.
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12 inch Truss Reflector "John"
102mm Celestron C102HD
Tasco 7TE5 60mm Classic
Tasco 9TE5 60mm Classic
Celestron Ultima 2000 SCT
Remains of an 8 inch dob
Celestron Comet catcher(orange tube)
1960 Edscorp Space Conquerer 6inch f/8
10x50 Bushnell Binoculars.
11T 4.5 inch Tasco reflector Lunograsso?
60mm Telescope Club
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rwiederrich
Goldfinger
Reged: 11/17/05
Posts: 8334
Loc: Bremerton Washington
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Quote:
Wow thats so cool to see.....thats got my blood pumping again,lol.
Aint it fun......
I'll double check the sagittal depth before I make the stone grinding tool....it was nearly close and it might even be a bit deaper then I intended(no problem)...it's all good.
Glad your blood's pumping again.... 
Rob
--------------------
www.goldmtobservingcenter.com
A great place for amateur astronomers, and ATM's to come and enjoy their hobby.
http://tech.groups.yahoo.com/group/HomemadeRefractorTelescopes/ My homemade refractor group.
www.vimeo.com/6014031
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droid
rocketman
Reged: 08/29/04
Posts: 4046
Loc: ohio
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if its slightly less than f/6 it doesnt matter.Its all good,lol 
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12 inch Truss Reflector "John"
102mm Celestron C102HD
Tasco 7TE5 60mm Classic
Tasco 9TE5 60mm Classic
Celestron Ultima 2000 SCT
Remains of an 8 inch dob
Celestron Comet catcher(orange tube)
1960 Edscorp Space Conquerer 6inch f/8
10x50 Bushnell Binoculars.
11T 4.5 inch Tasco reflector Lunograsso?
60mm Telescope Club
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droid
rocketman
Reged: 08/29/04
Posts: 4046
Loc: ohio
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Any updates?
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12 inch Truss Reflector "John"
102mm Celestron C102HD
Tasco 7TE5 60mm Classic
Tasco 9TE5 60mm Classic
Celestron Ultima 2000 SCT
Remains of an 8 inch dob
Celestron Comet catcher(orange tube)
1960 Edscorp Space Conquerer 6inch f/8
10x50 Bushnell Binoculars.
11T 4.5 inch Tasco reflector Lunograsso?
60mm Telescope Club
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droid
rocketman
Reged: 08/29/04
Posts: 4046
Loc: ohio
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guess not...lol
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12 inch Truss Reflector "John"
102mm Celestron C102HD
Tasco 7TE5 60mm Classic
Tasco 9TE5 60mm Classic
Celestron Ultima 2000 SCT
Remains of an 8 inch dob
Celestron Comet catcher(orange tube)
1960 Edscorp Space Conquerer 6inch f/8
10x50 Bushnell Binoculars.
11T 4.5 inch Tasco reflector Lunograsso?
60mm Telescope Club
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rwiederrich
Goldfinger
Reged: 11/17/05
Posts: 8334
Loc: Bremerton Washington
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Quote:
guess not...lol
Sorry bro...I'm in the middle of a move...so I'll get to it a bit later. Its full groung to the correct sagitta..just got to make the penny tool for fine grinding.
Believe me...I'll keep you in touch with every step. I'm done working on my 10"f/16 for now...so your mirror will be on the dockets for my attention.... 
Rob
--------------------
www.goldmtobservingcenter.com
A great place for amateur astronomers, and ATM's to come and enjoy their hobby.
http://tech.groups.yahoo.com/group/HomemadeRefractorTelescopes/ My homemade refractor group.
www.vimeo.com/6014031
|
droid
rocketman
Reged: 08/29/04
Posts: 4046
Loc: ohio
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I thought you lived at GOMOC...LOL.where moving to?
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12 inch Truss Reflector "John"
102mm Celestron C102HD
Tasco 7TE5 60mm Classic
Tasco 9TE5 60mm Classic
Celestron Ultima 2000 SCT
Remains of an 8 inch dob
Celestron Comet catcher(orange tube)
1960 Edscorp Space Conquerer 6inch f/8
10x50 Bushnell Binoculars.
11T 4.5 inch Tasco reflector Lunograsso?
60mm Telescope Club
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droid
rocketman
Reged: 08/29/04
Posts: 4046
Loc: ohio
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--------------------
12 inch Truss Reflector "John"
102mm Celestron C102HD
Tasco 7TE5 60mm Classic
Tasco 9TE5 60mm Classic
Celestron Ultima 2000 SCT
Remains of an 8 inch dob
Celestron Comet catcher(orange tube)
1960 Edscorp Space Conquerer 6inch f/8
10x50 Bushnell Binoculars.
11T 4.5 inch Tasco reflector Lunograsso?
60mm Telescope Club
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rwiederrich
Goldfinger
Reged: 11/17/05
Posts: 8334
Loc: Bremerton Washington
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Quote:
I thought you lived at GOMOC...LOL.where moving to?
I do...my office is next to my house...I have to move from my house to my office...  The slowing economy has me making life changes. I'm not selling it, just renting it.
The kids have and are moving away so life needs less house to survive. I still have my shops and my scope making ability...just more cramped.
I'm sorry I haven't worked on your mirror for some time...but I simply do not have the time currently. I did unload that monster 4 tub mirror making machine from my horse trailor..yesterday(cuz I'm selling the trailor too).
That thing will be great when making several mirrors/lenses at the same time. It is pre WW2 and is built like a tank. It weighs more then 1500lb. It is so nifty how it works and operates. 
I'll get back to scope making when I get fully moved....no worries. I still haven't opened that package you sent...I'm holding off till I feal satisfied with the mirror...just in case. 
Rob
--------------------
www.goldmtobservingcenter.com
A great place for amateur astronomers, and ATM's to come and enjoy their hobby.
http://tech.groups.yahoo.com/group/HomemadeRefractorTelescopes/ My homemade refractor group.
www.vimeo.com/6014031
|
droid
rocketman
Reged: 08/29/04
Posts: 4046
Loc: ohio
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I wish you would open that box and at least inspectthe contents.So I can quit worrying that something is wrong with it.,hehehehehehehehe
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12 inch Truss Reflector "John"
102mm Celestron C102HD
Tasco 7TE5 60mm Classic
Tasco 9TE5 60mm Classic
Celestron Ultima 2000 SCT
Remains of an 8 inch dob
Celestron Comet catcher(orange tube)
1960 Edscorp Space Conquerer 6inch f/8
10x50 Bushnell Binoculars.
11T 4.5 inch Tasco reflector Lunograsso?
60mm Telescope Club
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droid
rocketman
Reged: 08/29/04
Posts: 4046
Loc: ohio
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--------------------
12 inch Truss Reflector "John"
102mm Celestron C102HD
Tasco 7TE5 60mm Classic
Tasco 9TE5 60mm Classic
Celestron Ultima 2000 SCT
Remains of an 8 inch dob
Celestron Comet catcher(orange tube)
1960 Edscorp Space Conquerer 6inch f/8
10x50 Bushnell Binoculars.
11T 4.5 inch Tasco reflector Lunograsso?
60mm Telescope Club
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rwiederrich
Goldfinger
Reged: 11/17/05
Posts: 8334
Loc: Bremerton Washington
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I'm sure everything is fine.....it looks like you used the original box....
I'll make the fine grinding lap next week.
Rob
--------------------
www.goldmtobservingcenter.com
A great place for amateur astronomers, and ATM's to come and enjoy their hobby.
http://tech.groups.yahoo.com/group/HomemadeRefractorTelescopes/ My homemade refractor group.
www.vimeo.com/6014031
|
droid
rocketman
Reged: 08/29/04
Posts: 4046
Loc: ohio
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sweet look forward to seeing it.
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12 inch Truss Reflector "John"
102mm Celestron C102HD
Tasco 7TE5 60mm Classic
Tasco 9TE5 60mm Classic
Celestron Ultima 2000 SCT
Remains of an 8 inch dob
Celestron Comet catcher(orange tube)
1960 Edscorp Space Conquerer 6inch f/8
10x50 Bushnell Binoculars.
11T 4.5 inch Tasco reflector Lunograsso?
60mm Telescope Club
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droid
rocketman
Reged: 08/29/04
Posts: 4046
Loc: ohio
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back from the star party.Hope you had a good shoot.
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12 inch Truss Reflector "John"
102mm Celestron C102HD
Tasco 7TE5 60mm Classic
Tasco 9TE5 60mm Classic
Celestron Ultima 2000 SCT
Remains of an 8 inch dob
Celestron Comet catcher(orange tube)
1960 Edscorp Space Conquerer 6inch f/8
10x50 Bushnell Binoculars.
11T 4.5 inch Tasco reflector Lunograsso?
60mm Telescope Club
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rwiederrich
Goldfinger
Reged: 11/17/05
Posts: 8334
Loc: Bremerton Washington
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Quote:
back from the star party.Hope you had a good shoot.
Yes...I have been monitoring that thread line through out its duration....Did you have a good time...
Sure you did.. 
I canceled that too...it rained/hailed so hard any outdoor activity was unadvisable.... 
I'm aiming for next weekend..but that too looks funky.
I might just have to default to my Aug 15th date and leave it at that.
I worked on your mirror a bit more the other day. I needed to work on the sagitta a bit more..cuz I actually needed to make it deeper...
I'm tinkering....still.
Rob
--------------------
www.goldmtobservingcenter.com
A great place for amateur astronomers, and ATM's to come and enjoy their hobby.
http://tech.groups.yahoo.com/group/HomemadeRefractorTelescopes/ My homemade refractor group.
www.vimeo.com/6014031
|
droid
rocketman
Reged: 08/29/04
Posts: 4046
Loc: ohio
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I picked up the remains of Jasons (undermidnight) 12.5 inch ball scope.
The mirror cell will have to be fit dead center on an 18 inch back plate.
This thing is so cool, long rods that thread into the back plate which allow collimation from the top, how cool is that.
Jason was using commercial truss poles with ball on theyre ends, Ill have to work on that, as I doubt they were cheap.
And Ill need ot find 2 inch focuser some how.
Any ways take care.
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12 inch Truss Reflector "John"
102mm Celestron C102HD
Tasco 7TE5 60mm Classic
Tasco 9TE5 60mm Classic
Celestron Ultima 2000 SCT
Remains of an 8 inch dob
Celestron Comet catcher(orange tube)
1960 Edscorp Space Conquerer 6inch f/8
10x50 Bushnell Binoculars.
11T 4.5 inch Tasco reflector Lunograsso?
60mm Telescope Club
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Undermidnight
Pounder of Brass
Reged: 05/25/04
Posts: 2427
Loc: Hilliard, Ohio
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Andy,
The focuser was a Kineoptics HC-2 (www.kineoptics.com) and the truss system was from Moonlight (www.focuser.com). The truss system is not cheap, but worth it.
The mirror cell should be good to use for your mirror, you would just have to make an 18 point cell for it. The three holes in the mirror cell would be a good starting point 
As you embark on the madness.. er.. uh... adventure of making your own scope, let me know how I can help.
Jason
--------------------
WO Megrez 90 on EZTouch Mount
WO Zenithstar 66 on Microstar Mount
PST
8" F/4.2 Ball Scope, "Marilyn"
12.5" F/4.3 Ultralight, "Ada II"
11x70 Oberwerks
6" F/6 Polishing
Pans, Orthos, and Naglers
"We who cut mere stones, must always be envisioning cathedrals." - The Quarry Workers Creed
http://www.undermidnight.com
http://undermidnight.blogspot.com
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droid
rocketman
Reged: 08/29/04
Posts: 4046
Loc: ohio
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ok Jason your on , I have lots of questions....first up.
There arethree studs sticking up out of the bottem plate of the mirror cell, why??
Also...there are three of those little hammer in screw thingys, ones missing, an issue?
And last but not least in this photo.....the other three holes evenly spaced are I assume where the collimation roda screw in??
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12 inch Truss Reflector "John"
102mm Celestron C102HD
Tasco 7TE5 60mm Classic
Tasco 9TE5 60mm Classic
Celestron Ultima 2000 SCT
Remains of an 8 inch dob
Celestron Comet catcher(orange tube)
1960 Edscorp Space Conquerer 6inch f/8
10x50 Bushnell Binoculars.
11T 4.5 inch Tasco reflector Lunograsso?
60mm Telescope Club
|
Sky Captain
Metal Whisperer
Reged: 11/07/04
Posts: 7195
Loc: Issaquah, WA.
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Hey Andy, I was over at Rob's the other day and he showed me the progress on your mirror...looks great. 
Rob has a great optics testing bench (he tested my mirror and a very in-depth tour on mirror making), I was pretty impressed!
Your mirror is in good hands.
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Equipment Overload!
Kerry
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rwiederrich
Goldfinger
Reged: 11/17/05
Posts: 8334
Loc: Bremerton Washington
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Quote:
ok Jason your on , I have lots of questions....first up.
There arethree studs sticking up out of the bottem plate of the mirror cell, why??
Also...there are three of those little hammer in screw thingys, ones missing, an issue?
And last but not least in this photo.....the other three holes evenly spaced are I assume where the collimation roda screw in??
The three studs in the recesses are most likely the bolt points for three truss poles that had press bolts put in their ends. Then again..why would there only be three truss poles...? Yeah.. you had better keep asking the ex-owner.....
OK..I pushed the center down a bit more on your mirror to give me about an f/5.5. This is good because it allows me a bit of fudge room when porabolizing. I made the new fine grinding tool and I will be epoxying the copper pennies on it later today or this weekend...After that sets up its fine grinding time on the machine.......Yippy.
I'll post images of the tool and stuff a bit later.
Rob
--------------------
www.goldmtobservingcenter.com
A great place for amateur astronomers, and ATM's to come and enjoy their hobby.
http://tech.groups.yahoo.com/group/HomemadeRefractorTelescopes/ My homemade refractor group.
www.vimeo.com/6014031
|
droid
rocketman
Reged: 08/29/04
Posts: 4046
Loc: ohio
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Rob; cant wait to see photos....... , Im guessing at least two of those empty holes was for a sling???
--------------------
12 inch Truss Reflector "John"
102mm Celestron C102HD
Tasco 7TE5 60mm Classic
Tasco 9TE5 60mm Classic
Celestron Ultima 2000 SCT
Remains of an 8 inch dob
Celestron Comet catcher(orange tube)
1960 Edscorp Space Conquerer 6inch f/8
10x50 Bushnell Binoculars.
11T 4.5 inch Tasco reflector Lunograsso?
60mm Telescope Club
|
rwiederrich
Goldfinger
Reged: 11/17/05
Posts: 8334
Loc: Bremerton Washington
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Ok Andy....Finished the penny tool and put it to use.
Here is an image of the finished tool....mirror surface.
--------------------
www.goldmtobservingcenter.com
A great place for amateur astronomers, and ATM's to come and enjoy their hobby.
http://tech.groups.yahoo.com/group/HomemadeRefractorTelescopes/ My homemade refractor group.
www.vimeo.com/6014031
|
rwiederrich
Goldfinger
Reged: 11/17/05
Posts: 8334
Loc: Bremerton Washington
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Here it is on the mirror working. I like to inovate...so as you can see I have a water drip system...and that long metal tube is actually an antenna...I removed the tip and the securing end....afixed it to a jug of grit and as the over arm strokes the mirror..the lateral arm bumps the antenna and *thumps* out a nice amount of grit onto the mirror. This method is quite repetitious and I can set it up and walk away...letting this work by themselves..
I don't stand over a barrel and I surely don't stand over my machine manually sprinkling water and grit on the mirror.
I have another machine to be working on...trying to get into opperation...This frees me up.
--------------------
www.goldmtobservingcenter.com
A great place for amateur astronomers, and ATM's to come and enjoy their hobby.
http://tech.groups.yahoo.com/group/HomemadeRefractorTelescopes/ My homemade refractor group.
www.vimeo.com/6014031
|
rwiederrich
Goldfinger
Reged: 11/17/05
Posts: 8334
Loc: Bremerton Washington
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Here is a bit more closeup view of the grit antenna dispenser..
--------------------
www.goldmtobservingcenter.com
A great place for amateur astronomers, and ATM's to come and enjoy their hobby.
http://tech.groups.yahoo.com/group/HomemadeRefractorTelescopes/ My homemade refractor group.
www.vimeo.com/6014031
|
rwiederrich
Goldfinger
Reged: 11/17/05
Posts: 8334
Loc: Bremerton Washington
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Gonna let her run for several hours today.
I have another mirror that needs to get some time on the machine too...so we have to share the playground.
Good reason to get my new four tub machine in operation as soon as possible. Just need the drive chain and another sproket to arrive in the mail from McMaster-Carr...and I'll finish things up and move it into the mirror making shop and put it right next to this machine. 
Have a great weekend.
Rob
--------------------
www.goldmtobservingcenter.com
A great place for amateur astronomers, and ATM's to come and enjoy their hobby.
http://tech.groups.yahoo.com/group/HomemadeRefractorTelescopes/ My homemade refractor group.
www.vimeo.com/6014031
|
neo
professor emeritus
Reged: 02/12/08
Posts: 623
Loc: Iasi, Romania
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Hi Rob!
Nice work pal! 
I'm a bit intriguied about your penny tool. It works like a tile tool?
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Russian 15x50 binos
Home made 8" f/5 Newton on eq mount
Home made 70mm f/6 (Rodenstock Rotelar lens) Apo refractor
www.astronomy.ro
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droid
rocketman
Reged: 08/29/04
Posts: 4046
Loc: ohio
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Rob; that is so coool, I use a similiar machine a work to micropolish samples to be viewed under a microscope.
But I have to stay right there, add either water or diamond compound liquid as necessary.
I never thought to auto mate the water drip, thouhg I couldnt do the compounds like that as we use several for each job.
Id never heard of pennys for a polishing tool.Is this something new???
--------------------
12 inch Truss Reflector "John"
102mm Celestron C102HD
Tasco 7TE5 60mm Classic
Tasco 9TE5 60mm Classic
Celestron Ultima 2000 SCT
Remains of an 8 inch dob
Celestron Comet catcher(orange tube)
1960 Edscorp Space Conquerer 6inch f/8
10x50 Bushnell Binoculars.
11T 4.5 inch Tasco reflector Lunograsso?
60mm Telescope Club
|
rwiederrich
Goldfinger
Reged: 11/17/05
Posts: 8334
Loc: Bremerton Washington
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Quote:
Hi Rob!
Nice work pal!
I'm a bit intriguied about your penny tool. It works like a tile tool?
Yep. Tile tools simulate glass tools. Penny tools work in the same manner...but are way less expensive to make. JUst epoxy the pennies down and there you go. IMV they last longer too...
Rob
--------------------
www.goldmtobservingcenter.com
A great place for amateur astronomers, and ATM's to come and enjoy their hobby.
http://tech.groups.yahoo.com/group/HomemadeRefractorTelescopes/ My homemade refractor group.
www.vimeo.com/6014031
|
rwiederrich
Goldfinger
Reged: 11/17/05
Posts: 8334
Loc: Bremerton Washington
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Quote:
Rob; that is so coool, I use a similiar machine a work to micropolish samples to be viewed under a microscope.
But I have to stay right there, add either water or diamond compound liquid as necessary.
I never thought to auto mate the water drip, thouhg I couldnt do the compounds like that as we use several for each job.
Id never heard of pennys for a polishing tool.Is this something new???
Pennies are not new. Some folks use metal washers.
Remember it is the grit that is doing the cutting..the tile or penny is the part that contacts and permits the suspended grit to move among the tiles.
Yes they wear down..just like tiles(ONly slower).
Since pennies are generally the same thickness and size..they work well.
That's what I do anyway. There are many ways to skin a cat...or skunk.
Rob
--------------------
www.goldmtobservingcenter.com
A great place for amateur astronomers, and ATM's to come and enjoy their hobby.
http://tech.groups.yahoo.com/group/HomemadeRefractorTelescopes/ My homemade refractor group.
www.vimeo.com/6014031
|
Undermidnight
Pounder of Brass
Reged: 05/25/04
Posts: 2427
Loc: Hilliard, Ohio
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Quote:
ok Jason your on , I have lots of questions....first up.
There arethree studs sticking up out of the bottem plate of the mirror cell, why??
Also...there are three of those little hammer in screw thingys, ones missing, an issue?
And last but not least in this photo.....the other three holes evenly spaced are I assume where the collimation roda screw in??
Andy,
The three rods from the top were from the three struts I originally used. I stopped using the three strut design and went with a truss design. The bolts are just leftovers I thought about using them for fan mounts or something.
The t-nuts were for a threaded rod that was used to push against the wider top ring (pressing it against the inside lip of the ball.) The missing one would have to be replaced.
As for the threaded inserts, yep, those are for the collimation bolts.
Jason
--------------------
WO Megrez 90 on EZTouch Mount
WO Zenithstar 66 on Microstar Mount
PST
8" F/4.2 Ball Scope, "Marilyn"
12.5" F/4.3 Ultralight, "Ada II"
11x70 Oberwerks
6" F/6 Polishing
Pans, Orthos, and Naglers
"We who cut mere stones, must always be envisioning cathedrals." - The Quarry Workers Creed
http://www.undermidnight.com
http://undermidnight.blogspot.com
Edited by Undermidnight (06/27/09 11:04 PM)
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droid
rocketman
Reged: 08/29/04
Posts: 4046
Loc: ohio
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Rob; Im sure you already know this.....but if you work with epoxy regularly, or even part time, you sould always work in a well ventilated area, and wear gloves and a mask if needed.
Being an amatuer rocketeer, I developed an accute alergic reaction to epoxy , one wiff, and my lungues close down.
I used ot work indoors during the winter building kits.Not smart I know.
Just thought Id put this out there ,no disrespect is meant
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12 inch Truss Reflector "John"
102mm Celestron C102HD
Tasco 7TE5 60mm Classic
Tasco 9TE5 60mm Classic
Celestron Ultima 2000 SCT
Remains of an 8 inch dob
Celestron Comet catcher(orange tube)
1960 Edscorp Space Conquerer 6inch f/8
10x50 Bushnell Binoculars.
11T 4.5 inch Tasco reflector Lunograsso?
60mm Telescope Club
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droid
rocketman
Reged: 08/29/04
Posts: 4046
Loc: ohio
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One of the sites I am basing my ideas on....lol
http://www.sff.net/people/J.Oltion/trackball_optics.htm
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12 inch Truss Reflector "John"
102mm Celestron C102HD
Tasco 7TE5 60mm Classic
Tasco 9TE5 60mm Classic
Celestron Ultima 2000 SCT
Remains of an 8 inch dob
Celestron Comet catcher(orange tube)
1960 Edscorp Space Conquerer 6inch f/8
10x50 Bushnell Binoculars.
11T 4.5 inch Tasco reflector Lunograsso?
60mm Telescope Club
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droid
rocketman
Reged: 08/29/04
Posts: 4046
Loc: ohio
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just bumping this thread up
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12 inch Truss Reflector "John"
102mm Celestron C102HD
Tasco 7TE5 60mm Classic
Tasco 9TE5 60mm Classic
Celestron Ultima 2000 SCT
Remains of an 8 inch dob
Celestron Comet catcher(orange tube)
1960 Edscorp Space Conquerer 6inch f/8
10x50 Bushnell Binoculars.
11T 4.5 inch Tasco reflector Lunograsso?
60mm Telescope Club
|
droid
rocketman
Reged: 08/29/04
Posts: 4046
Loc: ohio
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happy fourth of July 
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12 inch Truss Reflector "John"
102mm Celestron C102HD
Tasco 7TE5 60mm Classic
Tasco 9TE5 60mm Classic
Celestron Ultima 2000 SCT
Remains of an 8 inch dob
Celestron Comet catcher(orange tube)
1960 Edscorp Space Conquerer 6inch f/8
10x50 Bushnell Binoculars.
11T 4.5 inch Tasco reflector Lunograsso?
60mm Telescope Club
|
droid
rocketman
Reged: 08/29/04
Posts: 4046
Loc: ohio
|
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--------------------
12 inch Truss Reflector "John"
102mm Celestron C102HD
Tasco 7TE5 60mm Classic
Tasco 9TE5 60mm Classic
Celestron Ultima 2000 SCT
Remains of an 8 inch dob
Celestron Comet catcher(orange tube)
1960 Edscorp Space Conquerer 6inch f/8
10x50 Bushnell Binoculars.
11T 4.5 inch Tasco reflector Lunograsso?
60mm Telescope Club
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mikey cee
Post Laureate
Reged: 01/18/07
Posts: 3531
Loc: bellevue ne.
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Rob.....Just keep Andy's mirror off the floor!! Mike
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7x35 and 10x50 sears tower binocs, 3" f/10 edmunds reflector, 2.4" f/11.7 manon refractor, 6" f/8 jaegers refractor, "The 8 Ball" 8" f/13.3 brandt refractor, 3" f/15.8 sans&streiffe refractor, 3.1" f/15 selsi refractor(towa 339), 2.4" f/15 sears refractor, selsi 30x30mm spyglass, criterion 5-draw 25x45x75x spyglass(1957), 4.25" f/14.8 tasco 20te.
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rwiederrich
Goldfinger
Reged: 11/17/05
Posts: 8334
Loc: Bremerton Washington
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Quote:
OK...here we go again. I rebuilt the grinding tool today.
I removed all the pennies and remounted all the same kind(2004 or newer) and placed them all Lincoln head down...so I would have a more regular contact.
So....I hook up to post and here you are...wondering where the heck I am...and I have more pix to show.
Here is the mirror with the new pennied tool working the mirror. This wider view show another 8" mirror getting ready to be tooled up for a round.
Rob
--------------------
www.goldmtobservingcenter.com
A great place for amateur astronomers, and ATM's to come and enjoy their hobby.
http://tech.groups.yahoo.com/group/HomemadeRefractorTelescopes/ My homemade refractor group.
www.vimeo.com/6014031
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rwiederrich
Goldfinger
Reged: 11/17/05
Posts: 8334
Loc: Bremerton Washington
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Quote:
Rob.....Just keep Andy's mirror off the floor!! Mike
Oh..I only do that to mirrors I have spent nearly a year of my time grinding/polishing on and are almost done...... 
I'm taking good care of Andy's mirror..if it isn't on the grinding table it is in the rubber sink.
Rob
--------------------
www.goldmtobservingcenter.com
A great place for amateur astronomers, and ATM's to come and enjoy their hobby.
http://tech.groups.yahoo.com/group/HomemadeRefractorTelescopes/ My homemade refractor group.
www.vimeo.com/6014031
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rwiederrich
Goldfinger
Reged: 11/17/05
Posts: 8334
Loc: Bremerton Washington
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Here is a closeup of the tool making its pass.
The finish is nearing a totaly evenness...just a bit more on the outter edge. I'm down to about 63 microns now.
--------------------
www.goldmtobservingcenter.com
A great place for amateur astronomers, and ATM's to come and enjoy their hobby.
http://tech.groups.yahoo.com/group/HomemadeRefractorTelescopes/ My homemade refractor group.
www.vimeo.com/6014031
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rwiederrich
Goldfinger
Reged: 11/17/05
Posts: 8334
Loc: Bremerton Washington
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One more closeup and then I'm heading back out to check on things. I'm going to do a Sharpie test next to see how even things are grinding.
See ya later.
Rob(I'll take pix)
--------------------
www.goldmtobservingcenter.com
A great place for amateur astronomers, and ATM's to come and enjoy their hobby.
http://tech.groups.yahoo.com/group/HomemadeRefractorTelescopes/ My homemade refractor group.
www.vimeo.com/6014031
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rwiederrich
Goldfinger
Reged: 11/17/05
Posts: 8334
Loc: Bremerton Washington
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Well back in from doing the sharpie test and cleaing things up.
I washed the mirror and laid the sharpie lines down.
Rob
--------------------
www.goldmtobservingcenter.com
A great place for amateur astronomers, and ATM's to come and enjoy their hobby.
http://tech.groups.yahoo.com/group/HomemadeRefractorTelescopes/ My homemade refractor group.
www.vimeo.com/6014031
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rwiederrich
Goldfinger
Reged: 11/17/05
Posts: 8334
Loc: Bremerton Washington
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Set things up and set the water drip and the grit drip.
You can see them both at the 11:00 oclock area.
--------------------
www.goldmtobservingcenter.com
A great place for amateur astronomers, and ATM's to come and enjoy their hobby.
http://tech.groups.yahoo.com/group/HomemadeRefractorTelescopes/ My homemade refractor group.
www.vimeo.com/6014031
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rwiederrich
Goldfinger
Reged: 11/17/05
Posts: 8334
Loc: Bremerton Washington
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I noticed after several minutes that I was getting some zonal grinding...not to worry..this is just an indicator that the new penny tool needs to *grind in*.
Some of the pennies are not getting full contact in the center. Eventually(after some time) the new tool will be fully contacting the mirror and the grind will continue uneventfully.
Several rounds with 63 micron grit and I'll check again.
Once I get a nice even grind...I will drop down to 32 micron grit.
Hope these images will help you stay excited.
I just had so much to do these past weeks.....I hope..now that the new machine is set up. to get into continuous grinding sessions...at around 2~3 hour sessions.
Have a great evening.
Rob
--------------------
www.goldmtobservingcenter.com
A great place for amateur astronomers, and ATM's to come and enjoy their hobby.
http://tech.groups.yahoo.com/group/HomemadeRefractorTelescopes/ My homemade refractor group.
www.vimeo.com/6014031
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Undermidnight
Pounder of Brass
Reged: 05/25/04
Posts: 2427
Loc: Hilliard, Ohio
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Rob,
What are you using for support on the mirror while grinding? It looks like a thin one.
Jason
--------------------
WO Megrez 90 on EZTouch Mount
WO Zenithstar 66 on Microstar Mount
PST
8" F/4.2 Ball Scope, "Marilyn"
12.5" F/4.3 Ultralight, "Ada II"
11x70 Oberwerks
6" F/6 Polishing
Pans, Orthos, and Naglers
"We who cut mere stones, must always be envisioning cathedrals." - The Quarry Workers Creed
http://www.undermidnight.com
http://undermidnight.blogspot.com
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droid
rocketman
Reged: 08/29/04
Posts: 4046
Loc: ohio
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looks to be rubber matt for drawers?????non skid, and things put.
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12 inch Truss Reflector "John"
102mm Celestron C102HD
Tasco 7TE5 60mm Classic
Tasco 9TE5 60mm Classic
Celestron Ultima 2000 SCT
Remains of an 8 inch dob
Celestron Comet catcher(orange tube)
1960 Edscorp Space Conquerer 6inch f/8
10x50 Bushnell Binoculars.
11T 4.5 inch Tasco reflector Lunograsso?
60mm Telescope Club
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rwiederrich
Goldfinger
Reged: 11/17/05
Posts: 8334
Loc: Bremerton Washington
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Quote:
Rob,
What are you using for support on the mirror while grinding? It looks like a thin one.
Jason
The mirror is a 12.5" X 1" blank of plate glass. It is resting on droor padding and the table is 1" thick cast iron.
It's stable for sure.
Rob
--------------------
www.goldmtobservingcenter.com
A great place for amateur astronomers, and ATM's to come and enjoy their hobby.
http://tech.groups.yahoo.com/group/HomemadeRefractorTelescopes/ My homemade refractor group.
www.vimeo.com/6014031
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rwiederrich
Goldfinger
Reged: 11/17/05
Posts: 8334
Loc: Bremerton Washington
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Quote:
looks to be rubber matt for drawers?????non skid, and things put.
That's right..I still had to put three small keepers on the table edge to keep the mirror from slipping under grinding pressure.
No problem.
Rob
--------------------
www.goldmtobservingcenter.com
A great place for amateur astronomers, and ATM's to come and enjoy their hobby.
http://tech.groups.yahoo.com/group/HomemadeRefractorTelescopes/ My homemade refractor group.
www.vimeo.com/6014031
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droid
rocketman
Reged: 08/29/04
Posts: 4046
Loc: ohio
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Rob; Im about ot open my mouth and remove all doubt of ignorance here....but, why a sharpie test, looking for low areas?
--------------------
12 inch Truss Reflector "John"
102mm Celestron C102HD
Tasco 7TE5 60mm Classic
Tasco 9TE5 60mm Classic
Celestron Ultima 2000 SCT
Remains of an 8 inch dob
Celestron Comet catcher(orange tube)
1960 Edscorp Space Conquerer 6inch f/8
10x50 Bushnell Binoculars.
11T 4.5 inch Tasco reflector Lunograsso?
60mm Telescope Club
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rwiederrich
Goldfinger
Reged: 11/17/05
Posts: 8334
Loc: Bremerton Washington
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Quote:
Rob; Im about ot open my mouth and remove all doubt of ignorance here....but, why a sharpie test, looking for low areas?
This test is a simple way to show me where exactly the tool is doing its work...and were exactly I have premature contact. Once the pennies are ground in the grind will be quite even.
I check the marks wear to the tool and see exactly what's going on.
Things are perfect currently and the grind is going well.
Just about 1/8" left till full edge contact and a good grind.
I'll shift to 32 micron grit after that.
Rob
--------------------
www.goldmtobservingcenter.com
A great place for amateur astronomers, and ATM's to come and enjoy their hobby.
http://tech.groups.yahoo.com/group/HomemadeRefractorTelescopes/ My homemade refractor group.
www.vimeo.com/6014031
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Undermidnight
Pounder of Brass
Reged: 05/25/04
Posts: 2427
Loc: Hilliard, Ohio
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Quote:
The mirror is a 12.5" X 1" blank of plate glass. It is resting on droor padding and the table is 1" thick cast iron.
It's stable for sure.
I was thinking in terms of astigmatism avoidance. I know with thinner mirrors, the backing of choice is good old shag carpet... Preferably green
Jason
--------------------
WO Megrez 90 on EZTouch Mount
WO Zenithstar 66 on Microstar Mount
PST
8" F/4.2 Ball Scope, "Marilyn"
12.5" F/4.3 Ultralight, "Ada II"
11x70 Oberwerks
6" F/6 Polishing
Pans, Orthos, and Naglers
"We who cut mere stones, must always be envisioning cathedrals." - The Quarry Workers Creed
http://www.undermidnight.com
http://undermidnight.blogspot.com
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droid
rocketman
Reged: 08/29/04
Posts: 4046
Loc: ohio
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Quote:
Quote:
The mirror is a 12.5" X 1" blank of plate glass. It is resting on droor padding and the table is 1" thick cast iron.
It's stable for sure.
I was thinking in terms of astigmatism avoidance. I know with thinner mirrors, the backing of choice is good old shag carpet... Preferably green
Jason
why green?
--------------------
12 inch Truss Reflector "John"
102mm Celestron C102HD
Tasco 7TE5 60mm Classic
Tasco 9TE5 60mm Classic
Celestron Ultima 2000 SCT
Remains of an 8 inch dob
Celestron Comet catcher(orange tube)
1960 Edscorp Space Conquerer 6inch f/8
10x50 Bushnell Binoculars.
11T 4.5 inch Tasco reflector Lunograsso?
60mm Telescope Club
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rwiederrich
Goldfinger
Reged: 11/17/05
Posts: 8334
Loc: Bremerton Washington
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Quote:
Quote:
The mirror is a 12.5" X 1" blank of plate glass. It is resting on droor padding and the table is 1" thick cast iron.
It's stable for sure.
I was thinking in terms of astigmatism avoidance. I know with thinner mirrors, the backing of choice is good old shag carpet... Preferably green
Jason
Riight.. I'm using black rubber carpet/droor liner. It is exceptional for leveling and preventing any astigmatic issues. Most folks use this....at least from what I gather.
Being rubbered it also holds my smaller mirrors from slipping around. I use small stops for the bigger mirrors.
Rob
--------------------
www.goldmtobservingcenter.com
A great place for amateur astronomers, and ATM's to come and enjoy their hobby.
http://tech.groups.yahoo.com/group/HomemadeRefractorTelescopes/ My homemade refractor group.
www.vimeo.com/6014031
|
Undermidnight
Pounder of Brass
Reged: 05/25/04
Posts: 2427
Loc: Hilliard, Ohio
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Quote:
Riight.. I'm using black rubber carpet/droor liner. It is exceptional for leveling and preventing any astigmatic issues. Most folks use this....at least from what I gather.
Being rubbered it also holds my smaller mirrors from slipping around. I use small stops for the bigger mirrors.
Rob
Rob,
Very cool. I have yet to do a thinner mirror. The 12.5" I did was about 2" I think. I used it on that mirror and others as well. It is some versatile stuff.
Excited to see the mirror (and scope) when done.
Jason
--------------------
WO Megrez 90 on EZTouch Mount
WO Zenithstar 66 on Microstar Mount
PST
8" F/4.2 Ball Scope, "Marilyn"
12.5" F/4.3 Ultralight, "Ada II"
11x70 Oberwerks
6" F/6 Polishing
Pans, Orthos, and Naglers
"We who cut mere stones, must always be envisioning cathedrals." - The Quarry Workers Creed
http://www.undermidnight.com
http://undermidnight.blogspot.com
Edited by Undermidnight (07/09/09 11:26 AM)
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Undermidnight
Pounder of Brass
Reged: 05/25/04
Posts: 2427
Loc: Hilliard, Ohio
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Quote:
why green?
Because our eye is the most sensitive to green light.
Just kidding. The earlier thin mirror makers used shag carpet and also the plastic "grass" door mats. Evenly supports the back of the mirror when working on them.
Looks like it is coming along great Andy and Rob!
--------------------
WO Megrez 90 on EZTouch Mount
WO Zenithstar 66 on Microstar Mount
PST
8" F/4.2 Ball Scope, "Marilyn"
12.5" F/4.3 Ultralight, "Ada II"
11x70 Oberwerks
6" F/6 Polishing
Pans, Orthos, and Naglers
"We who cut mere stones, must always be envisioning cathedrals." - The Quarry Workers Creed
http://www.undermidnight.com
http://undermidnight.blogspot.com
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rwiederrich
Goldfinger
Reged: 11/17/05
Posts: 8334
Loc: Bremerton Washington
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Quote:
Quote:
why green?
Because our eye is the most sensitive to green light.
Just kidding. The earlier thin mirror makers used shag carpet and also the plastic "grass" door mats. Evenly supports the back of the mirror when working on them.
Looks like it is coming along great Andy and Rob!
That is why my favorite color is green...and my scopes are painted green....
Lots of grinding to do before I can test and see where I'm at. But its a fun job and pretty easy on the machine.
I'll post more images as I go along.
Rob
--------------------
www.goldmtobservingcenter.com
A great place for amateur astronomers, and ATM's to come and enjoy their hobby.
http://tech.groups.yahoo.com/group/HomemadeRefractorTelescopes/ My homemade refractor group.
www.vimeo.com/6014031
|
Undermidnight
Pounder of Brass
Reged: 05/25/04
Posts: 2427
Loc: Hilliard, Ohio
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Quote:
That is why my favorite color is green...and my scopes are painted green....
Lots of grinding to do before I can test and see where I'm at. But its a fun job and pretty easy on the machine.
I'll post more images as I go along.
Rob
I am GREEN with envy..
--------------------
WO Megrez 90 on EZTouch Mount
WO Zenithstar 66 on Microstar Mount
PST
8" F/4.2 Ball Scope, "Marilyn"
12.5" F/4.3 Ultralight, "Ada II"
11x70 Oberwerks
6" F/6 Polishing
Pans, Orthos, and Naglers
"We who cut mere stones, must always be envisioning cathedrals." - The Quarry Workers Creed
http://www.undermidnight.com
http://undermidnight.blogspot.com
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rwiederrich
Goldfinger
Reged: 11/17/05
Posts: 8334
Loc: Bremerton Washington
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Quote:
Quote:
That is why my favorite color is green...and my scopes are painted green....
Lots of grinding to do before I can test and see where I'm at. But its a fun job and pretty easy on the machine.
I'll post more images as I go along.
Rob
I am GREEN with envy..
I only wish more of my CN friends lived close enough by to be able to make their own mirrors and scopes on these machines. Literally I can make 4 seporate mirrors on this new machine without breaking stride on any one of them.
In one of the pictures I posted you can see a smaller 8"f/6 being ground. I can set the 12.5" and let it go..while I work on the 8" completely independant and free from effecting the 12.5". It's really slick. Each Tub and over arm has its own clutch and speed control and over arm concentric stroke adjustment. Really it's 4 machines in one.
Now I can put my 17" back on the Porter polisher and work it as well without having to retool every time I change projects......
It is so fun to be able to have such flexability.
And now my testers test stand has rails that come completely to the tester itself. So my sled test stand can run along the rails.. 1ft from the tester all the way down the test bench 19ft to the other end so I can test my big long focus mirrors.
I can harly believe how far my optical shop has come in 2 years. I just need more folks wanting to building scopes to come by.
Finished helping a friend build his 20"f/4.7, and its first light was last week here at GOMOC...what a thrill.
Well...thanks for posting and for the encouragement.
Rob
--------------------
www.goldmtobservingcenter.com
A great place for amateur astronomers, and ATM's to come and enjoy their hobby.
http://tech.groups.yahoo.com/group/HomemadeRefractorTelescopes/ My homemade refractor group.
www.vimeo.com/6014031
|
rwiederrich
Goldfinger
Reged: 11/17/05
Posts: 8334
Loc: Bremerton Washington
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Did another sharpie test and set it up to run for a couple hours between patients.
I'll check in on it in a couple to see where we are at. Just a bit more edge to clean up from the original curve generation. Once this grit gets things down...I'll change to 32 micron grit.
So now it's time to just let it grind.
Rob(Later)
--------------------
www.goldmtobservingcenter.com
A great place for amateur astronomers, and ATM's to come and enjoy their hobby.
http://tech.groups.yahoo.com/group/HomemadeRefractorTelescopes/ My homemade refractor group.
www.vimeo.com/6014031
|
Undermidnight
Pounder of Brass
Reged: 05/25/04
Posts: 2427
Loc: Hilliard, Ohio
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Rob,
You know what they say about having the right tools.. it sure makes the job easier. I would probably enjoy mirror making more if I had the proper tools at home. We have come a long way at the observatory. Our video tester really helps out a TON. I tested my mirrors using my good old eye (and sore back). Now with the video tester, it is a breeze to test and multiple people can watch at the same time and keep me honest
Jason
--------------------
WO Megrez 90 on EZTouch Mount
WO Zenithstar 66 on Microstar Mount
PST
8" F/4.2 Ball Scope, "Marilyn"
12.5" F/4.3 Ultralight, "Ada II"
11x70 Oberwerks
6" F/6 Polishing
Pans, Orthos, and Naglers
"We who cut mere stones, must always be envisioning cathedrals." - The Quarry Workers Creed
http://www.undermidnight.com
http://undermidnight.blogspot.com
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rwiederrich
Goldfinger
Reged: 11/17/05
Posts: 8334
Loc: Bremerton Washington
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Quote:
Rob,
You know what they say about having the right tools.. it sure makes the job easier. I would probably enjoy mirror making more if I had the proper tools at home. We have come a long way at the observatory. Our video tester really helps out a TON. I tested my mirrors using my good old eye (and sore back). Now with the video tester, it is a breeze to test and multiple people can watch at the same time and keep me honest
Jason
Right...hey is that video eye you use for testing..color or just BW? Also does it actual do the testing or just captures the foulcault/Rochi image and projects it on a screen for you to evaluate?
Rob
--------------------
www.goldmtobservingcenter.com
A great place for amateur astronomers, and ATM's to come and enjoy their hobby.
http://tech.groups.yahoo.com/group/HomemadeRefractorTelescopes/ My homemade refractor group.
www.vimeo.com/6014031
|
droid
rocketman
Reged: 08/29/04
Posts: 4046
Loc: ohio
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video tester???? yall are way over my head...lol
--------------------
12 inch Truss Reflector "John"
102mm Celestron C102HD
Tasco 7TE5 60mm Classic
Tasco 9TE5 60mm Classic
Celestron Ultima 2000 SCT
Remains of an 8 inch dob
Celestron Comet catcher(orange tube)
1960 Edscorp Space Conquerer 6inch f/8
10x50 Bushnell Binoculars.
11T 4.5 inch Tasco reflector Lunograsso?
60mm Telescope Club
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rwiederrich
Goldfinger
Reged: 11/17/05
Posts: 8334
Loc: Bremerton Washington
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Quote:
video tester???? yall are way over my head...lol
What I think that is being said is a video camera is placed at the focal plane and the image is captured for all to see the foulcault or Rochi test results. When many people can simultaniously see the test....you can't say it was better then it actually is.......
I'm going to try and oput my hand to making a camera to do the same thing. It means you don't have to bend over and peer through your tester...but simply watch a video screen or TV monitor.
Rob
--------------------
www.goldmtobservingcenter.com
A great place for amateur astronomers, and ATM's to come and enjoy their hobby.
http://tech.groups.yahoo.com/group/HomemadeRefractorTelescopes/ My homemade refractor group.
www.vimeo.com/6014031
|
Undermidnight
Pounder of Brass
Reged: 05/25/04
Posts: 2427
Loc: Hilliard, Ohio
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Quote:
Right...hey is that video eye you use for testing..color or just BW? Also does it actual do the testing or just captures the foulcault/Rochi image and projects it on a screen for you to evaluate?
Rob
Rob,
Sorry I did not reply sooner.. your post slipped by me.
It is an old security camera we use and it is in B/W. And it just displays the images to us. We hope to get a robotester done soon where it will do the knife edge testing for us. Pretty neat stuff!!
Here is Gary, the technical director of Perkins Observatory, testing a mirror with the tester.
--------------------
WO Megrez 90 on EZTouch Mount
WO Zenithstar 66 on Microstar Mount
PST
8" F/4.2 Ball Scope, "Marilyn"
12.5" F/4.3 Ultralight, "Ada II"
11x70 Oberwerks
6" F/6 Polishing
Pans, Orthos, and Naglers
"We who cut mere stones, must always be envisioning cathedrals." - The Quarry Workers Creed
http://www.undermidnight.com
http://undermidnight.blogspot.com
|
Undermidnight
Pounder of Brass
Reged: 05/25/04
Posts: 2427
Loc: Hilliard, Ohio
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|
Here is my 6" F/6 mirror that someday I hope to finish!!
--------------------
WO Megrez 90 on EZTouch Mount
WO Zenithstar 66 on Microstar Mount
PST
8" F/4.2 Ball Scope, "Marilyn"
12.5" F/4.3 Ultralight, "Ada II"
11x70 Oberwerks
6" F/6 Polishing
Pans, Orthos, and Naglers
"We who cut mere stones, must always be envisioning cathedrals." - The Quarry Workers Creed
http://www.undermidnight.com
http://undermidnight.blogspot.com
Edited by Undermidnight (07/10/09 09:20 PM)
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Undermidnight
Pounder of Brass
Reged: 05/25/04
Posts: 2427
Loc: Hilliard, Ohio
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|
Quote:
I'm going to try and oput my hand to making a camera to do the same thing. It means you don't have to bend over and peer through your tester...but simply watch a video screen or TV monitor.
Yep! Saves with a sore back. I have found that your testing accuracy is inversely proportional to the length of time hunched over, looking through the tester.
--------------------
WO Megrez 90 on EZTouch Mount
WO Zenithstar 66 on Microstar Mount
PST
8" F/4.2 Ball Scope, "Marilyn"
12.5" F/4.3 Ultralight, "Ada II"
11x70 Oberwerks
6" F/6 Polishing
Pans, Orthos, and Naglers
"We who cut mere stones, must always be envisioning cathedrals." - The Quarry Workers Creed
http://www.undermidnight.com
http://undermidnight.blogspot.com
|
rwiederrich
Goldfinger
Reged: 11/17/05
Posts: 8334
Loc: Bremerton Washington
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Yep..just what I thought. I have several cameras that I plan on doing the same thing with.....Sweet.
Good to see the same idea in actual practice.
Rob
--------------------
www.goldmtobservingcenter.com
A great place for amateur astronomers, and ATM's to come and enjoy their hobby.
http://tech.groups.yahoo.com/group/HomemadeRefractorTelescopes/ My homemade refractor group.
www.vimeo.com/6014031
|
rwiederrich
Goldfinger
Reged: 11/17/05
Posts: 8334
Loc: Bremerton Washington
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Quote:
Here is my 6" F/6 mirror that someday I hope to finish!!
Almost a sphere......  this is an image taken of the TV screen of your Rochi test?
Rob
--------------------
www.goldmtobservingcenter.com
A great place for amateur astronomers, and ATM's to come and enjoy their hobby.
http://tech.groups.yahoo.com/group/HomemadeRefractorTelescopes/ My homemade refractor group.
www.vimeo.com/6014031
|
rwiederrich
Goldfinger
Reged: 11/17/05
Posts: 8334
Loc: Bremerton Washington
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|
Quote:
Quote:
I'm going to try and oput my hand to making a camera to do the same thing. It means you don't have to bend over and peer through your tester...but simply watch a video screen or TV monitor.
Yep! Saves with a sore back. I have found that your testing accuracy is inversely proportional to the length of time hunched over, looking through the tester.
I'm assuming you removed the lens from the camera...so you could get the CCD chip to see the exact ROC without any interferance by lenses?
I got that very camera to do the same.
I have droids mirror ground pretty well with 63 micron grit...but I'm fighting the edges to polish out.
I think I'll throw it on the test stand just to see the KE test to see my spherical progress...
I'll sttempt to take pix of it.
Rob
Rob
--------------------
www.goldmtobservingcenter.com
A great place for amateur astronomers, and ATM's to come and enjoy their hobby.
http://tech.groups.yahoo.com/group/HomemadeRefractorTelescopes/ My homemade refractor group.
www.vimeo.com/6014031
|
jayscheuerle
Post Laureate
Reged: 01/16/06
Posts: 4076
Loc: S. Philadelphia, PA
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Quote:
One of the sites I am basing my ideas on....lol
http://www.sff.net/people/J.Oltion/trackball_optics.htm
If you're going ball, you may want to take a look at my 2 Eeros in terms of the frontside collimation cell, counterweight and truss connections. - j
Eero2
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Fight indignorance!
The Green Goblin - 12" of dobsonian excellence!
The PortaBowl-a $100 4.5" f/8 ball-scope YOU can build!
Eero2-a 6" f/5 ball-scope you probably can't.
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rwiederrich
Goldfinger
Reged: 11/17/05
Posts: 8334
Loc: Bremerton Washington
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OK...just having some fun today....Before I began fine grinding on Droids(and several other mirrors) today..I thought it might be fun to throw it on the test stand just to see the rough surface and see where I am.
This is a shadow gram of the surface....as you can see(that it is a bad image)..you can also see the low center and the high edges. I sprayed the glass with a soap/water mix to get it to reflect this much.
Any comments let me know.
Rob
--------------------
www.goldmtobservingcenter.com
A great place for amateur astronomers, and ATM's to come and enjoy their hobby.
http://tech.groups.yahoo.com/group/HomemadeRefractorTelescopes/ My homemade refractor group.
www.vimeo.com/6014031
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rwiederrich
Goldfinger
Reged: 11/17/05
Posts: 8334
Loc: Bremerton Washington
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Before I put my 17" back on the stand I wanted to see its very rough surface too.
From this poor gram..you can still see the unreflective edge. This mirror too has a deep center and high edge.
No problem.
Feel free to comment.
Rob
--------------------
www.goldmtobservingcenter.com
A great place for amateur astronomers, and ATM's to come and enjoy their hobby.
http://tech.groups.yahoo.com/group/HomemadeRefractorTelescopes/ My homemade refractor group.
www.vimeo.com/6014031
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rwiederrich
Goldfinger
Reged: 11/17/05
Posts: 8334
Loc: Bremerton Washington
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After taking a look at the mirrors surfaces..I put them on their perspective machines. While I was setting the water up..it dawned on me...I put one large water container up and inserted into it several very fine rubber tubings.
Sucked on them and created capillary action drips for each and then placed small clamps on the hoses to slow the dripps down...... Why didn't this dawn on me before...
I can use one water sourse and as many thin (dental) tubes as needed to each table. Anyway....
I put my 17" on the Porter polisher and the 8" on the first table in the new polisher and Droids 12.5" on the second tubs table.
Set them all up with different strokes and over hangs(due to the correction I need to make for each)..and began staring them all up. First Droid's....then my 17" and finally the smaller 8" of one of my students. That one will see little grinding...just tooling..so he can be involved as much as possible on his mirror.
So here are several pictures of all three running together.
Rob
--------------------
www.goldmtobservingcenter.com
A great place for amateur astronomers, and ATM's to come and enjoy their hobby.
http://tech.groups.yahoo.com/group/HomemadeRefractorTelescopes/ My homemade refractor group.
www.vimeo.com/6014031
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rwiederrich
Goldfinger
Reged: 11/17/05
Posts: 8334
Loc: Bremerton Washington
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And another view.
--------------------
www.goldmtobservingcenter.com
A great place for amateur astronomers, and ATM's to come and enjoy their hobby.
http://tech.groups.yahoo.com/group/HomemadeRefractorTelescopes/ My homemade refractor group.
www.vimeo.com/6014031
|
rwiederrich
Goldfinger
Reged: 11/17/05
Posts: 8334
Loc: Bremerton Washington
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And one final view...that is better.
You can see each doing its own thing.
The 17" to the left....8" in the middle and Droid's 12.5 there on the right.
My plan is to set up the water for all and a grit drip system for all too. Each student or myself can run all 5 stations independantly of each other. Soooo cooool.
Well..it's been farely busy this morning and I need to go check on the mirrors.....
Thanks for peeking in.
Rob
--------------------
www.goldmtobservingcenter.com
A great place for amateur astronomers, and ATM's to come and enjoy their hobby.
http://tech.groups.yahoo.com/group/HomemadeRefractorTelescopes/ My homemade refractor group.
www.vimeo.com/6014031
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rwiederrich
Goldfinger
Reged: 11/17/05
Posts: 8334
Loc: Bremerton Washington
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I had such a great day today working in the optical shop.
Playin with glass has been fun and being a nice clear day helped. Rain is in the forcast for the next several days...
I pushed the edges on both mirrors (17"..12.5") back and things are really looking up.
The tool for the 12.5 still is having center issues and I really need to work it in further.
It just takes time on the machines....an hour can seam like for ever when you're just watching things. Both mirrors ran for about 4 hours.
What a great experience.....and to test so many mirrors right after each other was way fun too.
I hope to put some more time into them tomorrow......if I can.
Rob
--------------------
www.goldmtobservingcenter.com
A great place for amateur astronomers, and ATM's to come and enjoy their hobby.
http://tech.groups.yahoo.com/group/HomemadeRefractorTelescopes/ My homemade refractor group.
www.vimeo.com/6014031
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droid
rocketman
Reged: 08/29/04
Posts: 4046
Loc: ohio
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Rob; this thread is so cooool......I often dont know what your saying but thats ok......knowing its half way there is exciting all in itself.
And seeing your machines in action is cooool too.
Hmm wonder if videos could be posted in here????
--------------------
12 inch Truss Reflector "John"
102mm Celestron C102HD
Tasco 7TE5 60mm Classic
Tasco 9TE5 60mm Classic
Celestron Ultima 2000 SCT
Remains of an 8 inch dob
Celestron Comet catcher(orange tube)
1960 Edscorp Space Conquerer 6inch f/8
10x50 Bushnell Binoculars.
11T 4.5 inch Tasco reflector Lunograsso?
60mm Telescope Club
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rwiederrich
Goldfinger
Reged: 11/17/05
Posts: 8334
Loc: Bremerton Washington
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Quote:
Rob; this thread is so cooool......I often dont know what your saying but thats ok......knowing its half way there is exciting all in itself.
And seeing your machines in action is cooool too.
Hmm wonder if videos could be posted in here????
I know its so fun. What have I said you don't know about?
I can help if you're not understanding stuff. Just ask.
It's almost like a dream.....
What's your thoughts on your mirror?
Rob
--------------------
www.goldmtobservingcenter.com
A great place for amateur astronomers, and ATM's to come and enjoy their hobby.
http://tech.groups.yahoo.com/group/HomemadeRefractorTelescopes/ My homemade refractor group.
www.vimeo.com/6014031
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droid
rocketman
Reged: 08/29/04
Posts: 4046
Loc: ohio
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Well it appers to be coming along well.......though that would just be a guess.
Im fascinated bye all the automated equipment, think thyell speed up mirror making?
as for what dont I know?? well umm let me see, the photos youll posted of the test photos, havent a clue what they mean,or, show.
And the terminology is a bit ,at times, beyond me.
On the upp side Ive been following some of the other threads in the atm forum,so Im learning something new daily.
Dont worry about explaining everything to me, lol....just do what you do best.
--------------------
12 inch Truss Reflector "John"
102mm Celestron C102HD
Tasco 7TE5 60mm Classic
Tasco 9TE5 60mm Classic
Celestron Ultima 2000 SCT
Remains of an 8 inch dob
Celestron Comet catcher(orange tube)
1960 Edscorp Space Conquerer 6inch f/8
10x50 Bushnell Binoculars.
11T 4.5 inch Tasco reflector Lunograsso?
60mm Telescope Club
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Undermidnight
Pounder of Brass
Reged: 05/25/04
Posts: 2427
Loc: Hilliard, Ohio
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Quote:
Almost a sphere...... this is an image taken of the TV screen of your Rochi test?
Rob
Just a shot of the TV screen. I am doing accentuated pressure just inside the edge (Texerau's technique) and it is slowly getting rid of the edge.
Jason (In Washington DC this week)
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WO Megrez 90 on EZTouch Mount
WO Zenithstar 66 on Microstar Mount
PST
8" F/4.2 Ball Scope, "Marilyn"
12.5" F/4.3 Ultralight, "Ada II"
11x70 Oberwerks
6" F/6 Polishing
Pans, Orthos, and Naglers
"We who cut mere stones, must always be envisioning cathedrals." - The Quarry Workers Creed
http://www.undermidnight.com
http://undermidnight.blogspot.com
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droid
rocketman
Reged: 08/29/04
Posts: 4046
Loc: ohio
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Im also excited to see it happening.......antsi to touch it ...lol.
At the same realizing it might be some time before Ill be able to get it coated.
on the other hand it might be a great solar scope ,seeing as it will allow all the light to pass straight through...lol.
As for the images...I looked at them ...and it looked liked like the edges were high, and so was the center, while a donut like area was lower, I see I was wrong...hehehehehehee
--------------------
12 inch Truss Reflector "John"
102mm Celestron C102HD
Tasco 7TE5 60mm Classic
Tasco 9TE5 60mm Classic
Celestron Ultima 2000 SCT
Remains of an 8 inch dob
Celestron Comet catcher(orange tube)
1960 Edscorp Space Conquerer 6inch f/8
10x50 Bushnell Binoculars.
11T 4.5 inch Tasco reflector Lunograsso?
60mm Telescope Club
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rwiederrich
Goldfinger
Reged: 11/17/05
Posts: 8334
Loc: Bremerton Washington
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Quote:
Im also excited to see it happening.......antsi to touch it ...lol.
At the same realizing it might be some time before Ill be able to get it coated.
on the other hand it might be a great solar scope ,seeing as it will allow all the light to pass straight through...lol.
As for the images...I looked at them ...and it looked liked like the edges were high, and so was the center, while a donut like area was lower, I see I was wrong...hehehehehehee
I played with different grit dispensors today...and I found a very neet way to sprinkle grit on the mirror.
I first used a magnetic dial indicator base and fixed it to the over arm control arm of the drive next to the one I'm using....Zip tied my bottle of grit to an armbeture I made to attach to the magnetic aperatus. Then adjusted it and as the over arm ecentric arm throws in its stroke..it bumps the grit bottle and drips grit on the mirror...slick and easy and very urgenomic.
Check it out.
Rob
--------------------
www.goldmtobservingcenter.com
A great place for amateur astronomers, and ATM's to come and enjoy their hobby.
http://tech.groups.yahoo.com/group/HomemadeRefractorTelescopes/ My homemade refractor group.
www.vimeo.com/6014031
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rwiederrich
Goldfinger
Reged: 11/17/05
Posts: 8334
Loc: Bremerton Washington
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And one more picture.
this works slick and I can have room for others on all the other tables......
I'm working the edge on your mirror.
Rob
--------------------
www.goldmtobservingcenter.com
A great place for amateur astronomers, and ATM's to come and enjoy their hobby.
http://tech.groups.yahoo.com/group/HomemadeRefractorTelescopes/ My homemade refractor group.
www.vimeo.com/6014031
|
droid
rocketman
Reged: 08/29/04
Posts: 4046
Loc: ohio
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So maybe I was right the edge and center were higher than the donut shaped area????? ohhh ok, I suppose I couldnt have guessed anybetter....hehehehehehehehehe.
It actually is starting to look like a mirror or is it my overly active wishanation
ever chuck a piece of glass in frustration
--------------------
12 inch Truss Reflector "John"
102mm Celestron C102HD
Tasco 7TE5 60mm Classic
Tasco 9TE5 60mm Classic
Celestron Ultima 2000 SCT
Remains of an 8 inch dob
Celestron Comet catcher(orange tube)
1960 Edscorp Space Conquerer 6inch f/8
10x50 Bushnell Binoculars.
11T 4.5 inch Tasco reflector Lunograsso?
60mm Telescope Club
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rwiederrich
Goldfinger
Reged: 11/17/05
Posts: 8334
Loc: Bremerton Washington
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Quote:
So maybe I was right the edge and center were higher than the donut shaped area????? ohhh ok, I suppose I couldnt have guessed anybetter....hehehehehehehehehe.
It actually is starting to look like a mirror or is it my overly active wishanation
ever chuck a piece of glass in frustration
Actually that shadowgram showed the areas that are more polished then the other areas. Machine polishing tends to leave the edges a bit harder to get. Well with stroke polishing anyway. I'm fine grinding the edges..not pushing it down. Once done..I will return to the 10%~15% *W* stroke to even up the sphere. Once done..I'll test it again. Then off to finer grinding. I'm not correcting as of yet...just spherizing....
Rob
--------------------
www.goldmtobservingcenter.com
A great place for amateur astronomers, and ATM's to come and enjoy their hobby.
http://tech.groups.yahoo.com/group/HomemadeRefractorTelescopes/ My homemade refractor group.
www.vimeo.com/6014031
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rwiederrich
Goldfinger
Reged: 11/17/05
Posts: 8334
Loc: Bremerton Washington
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Andy..check out this link to a video I took of the grinding of your mirror with the new grit applicator.
www.vimeo.com/5602737
Rob
--------------------
www.goldmtobservingcenter.com
A great place for amateur astronomers, and ATM's to come and enjoy their hobby.
http://tech.groups.yahoo.com/group/HomemadeRefractorTelescopes/ My homemade refractor group.
www.vimeo.com/6014031
|
droid
rocketman
Reged: 08/29/04
Posts: 4046
Loc: ohio
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Wow that is so cool, a couple observations? is that a pot lid on top of the grinding or polishing tool? if so good use of old stuff Id have never thought of that.
Even better use of the mag base, I used ot do the calibrations of all company tools, and we had tons of these bases,though I had never given them a second thought, until now.lol.
So how far along are you do you think?half way?
and lastly , coke or pepsi.....enquiring minds want to know.
--------------------
12 inch Truss Reflector "John"
102mm Celestron C102HD
Tasco 7TE5 60mm Classic
Tasco 9TE5 60mm Classic
Celestron Ultima 2000 SCT
Remains of an 8 inch dob
Celestron Comet catcher(orange tube)
1960 Edscorp Space Conquerer 6inch f/8
10x50 Bushnell Binoculars.
11T 4.5 inch Tasco reflector Lunograsso?
60mm Telescope Club
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veebs2
special label
Reged: 03/13/07
Posts: 287
Loc: DeKalb, IL
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Given the red cap...I am going with a coke bottle. 
--------------------
Paul
Zhumell 10" (My Mistress - name given by my wife)
Hyperions - 5mm, 13mm and 24mm
Stratus - 8mm and 17mm
Howie Glatter 2"-1 1/4" Holograpic w/ Barlow
Lumicon OIII Filter
Telrad
DeKalb, IL
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rwiederrich
Goldfinger
Reged: 11/17/05
Posts: 8334
Loc: Bremerton Washington
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Quote:
Wow that is so cool, a couple observations? is that a pot lid on top of the grinding or polishing tool? if so good use of old stuff Id have never thought of that.
Even better use of the mag base, I used ot do the calibrations of all company tools, and we had tons of these bases,though I had never given them a second thought, until now.lol.
So how far along are you do you think?half way?
and lastly , coke or pepsi.....enquiring minds want to know.
Stainless pot lid is correct for 300.......
It makes perfect sence to use old stuff that we would otherwise discard. It has an extremely hard composite handle I drilled the quill tip ball socket in. Plus it holds the dental die stone very well...and I incorporated the *Lip* of the lid to help retain the stone. Suficient undercut exists inside the lid to hold the die stone as well.
And yes..that's a Coke bottle. The applicator tip is from my lab. If you noticed...the spring adjust on the magnetic holder arm can be adjusted to permit little or a lot of contact with the over arm..permitting me to adjust the amount of grit dispenced on the mirror. It works very well for my needs.
This set up is strictly for grinding. Once I'm good and smooth at this grind...I'll change everything over to a finer grit...and begin all over. Cerium for polishing will be suspended in water and dripped on the mirror. That's later.
Some larger grit(or something) got between the tool and glass and made a scratch....so I'll have to go with this grit a bit longer to remove it. One very important reason why you make sure your tool is always cleaned well between grits. It might have also been contamination in the grit stock. No problem.
I wouldn't say I'm half way. The mirror is getting very smooth...but I have to remove this scratch and I need to still come down several more grit sizes...before I even think about the pitch lap for polishing.
We're getting there...so hang in there. One thing I wanted to note...that large defect in the back of the mirror might become an issue when I begin polishing...due to support issues in that area. We'll see.
Later.
Rob
--------------------
www.goldmtobservingcenter.com
A great place for amateur astronomers, and ATM's to come and enjoy their hobby.
http://tech.groups.yahoo.com/group/HomemadeRefractorTelescopes/ My homemade refractor group.
www.vimeo.com/6014031
|
rwiederrich
Goldfinger
Reged: 11/17/05
Posts: 8334
Loc: Bremerton Washington
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Quote:
Given the red cap...I am going with a coke bottle.
Yeah...I didn't have a Mtn Dew bottle handy at the time....
Rob
--------------------
www.goldmtobservingcenter.com
A great place for amateur astronomers, and ATM's to come and enjoy their hobby.
http://tech.groups.yahoo.com/group/HomemadeRefractorTelescopes/ My homemade refractor group.
www.vimeo.com/6014031
|
droid
rocketman
Reged: 08/29/04
Posts: 4046
Loc: ohio
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have you checked ot see if you could patent that idea?
--------------------
12 inch Truss Reflector "John"
102mm Celestron C102HD
Tasco 7TE5 60mm Classic
Tasco 9TE5 60mm Classic
Celestron Ultima 2000 SCT
Remains of an 8 inch dob
Celestron Comet catcher(orange tube)
1960 Edscorp Space Conquerer 6inch f/8
10x50 Bushnell Binoculars.
11T 4.5 inch Tasco reflector Lunograsso?
60mm Telescope Club
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rwiederrich
Goldfinger
Reged: 11/17/05
Posts: 8334
Loc: Bremerton Washington
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Quote:
have you checked ot see if you could patent that idea?
Not really..because it's pretty much idealic to my particular machine. I have devised other ways to dispence grit on my Porter Polishing machine as well.
All the professionals who post on these threads have devised their own methods..some are probably even better then what I have come up with.
In an hour or so...I'll go back out to the mirror shop and set up for more grinding. It should grind for several hours today. I'm going for 15% overhang to get the edges and define the sphere.
Rob
--------------------
www.goldmtobservingcenter.com
A great place for amateur astronomers, and ATM's to come and enjoy their hobby.
http://tech.groups.yahoo.com/group/HomemadeRefractorTelescopes/ My homemade refractor group.
www.vimeo.com/6014031
|
droid
rocketman
Reged: 08/29/04
Posts: 4046
Loc: ohio
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so.........assuming a final focal length of around f/6 what size secondary will I need?
--------------------
12 inch Truss Reflector "John"
102mm Celestron C102HD
Tasco 7TE5 60mm Classic
Tasco 9TE5 60mm Classic
Celestron Ultima 2000 SCT
Remains of an 8 inch dob
Celestron Comet catcher(orange tube)
1960 Edscorp Space Conquerer 6inch f/8
10x50 Bushnell Binoculars.
11T 4.5 inch Tasco reflector Lunograsso?
60mm Telescope Club
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dymo
member
Reged: 02/28/09
Posts: 12
Loc: Germany
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Quote:
Quote:
Given the red cap...I am going with a coke bottle.
Yeah...I didn't have a Mtn Dew bottle handy at the time....
Rob
Thats too funny, I showed my wife the pics, her first response was NO NO NO, you cant build one, even though i hadnt even asked. Then in the middle of explaining to me why I cant build one, she paused and said " is that a coke bottle?", and i smiled yeah, I bet he didnt have a Mountain Dew bottle at hand when he built it.
I love this thread, its great when the professionals chime in, but i love it more for those who have never done a mirror, to see the step by step progress, and the machines used, along with the "simple" solutions to basic problems. It gives the truely amateurs like me a chance to see the whole process, and gives us not only what was done, buy why it was done.
So thanks for a great source of information
--------------------
I have round thing with a mirror in the bottom, attached to spinny thing, and it lets me see shiny objects in the dark....
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rwiederrich
Goldfinger
Reged: 11/17/05
Posts: 8334
Loc: Bremerton Washington
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Quote:
Quote:
Quote:
Given the red cap...I am going with a coke bottle.
Yeah...I didn't have a Mtn Dew bottle handy at the time....
Rob
Thats too funny, I showed my wife the pics, her first response was NO NO NO, you cant build one, even though i hadnt even asked. Then in the middle of explaining to me why I cant build one, she paused and said " is that a coke bottle?", and i smiled yeah, I bet he didnt have a Mountain Dew bottle at hand when he built it.
I love this thread, its great when the professionals chime in, but i love it more for those who have never done a mirror, to see the step by step progress, and the machines used, along with the "simple" solutions to basic problems. It gives the truely amateurs like me a chance to see the whole process, and gives us not only what was done, buy why it was done.
So thanks for a great source of information
Mtn Dew is my fave........
Anyway...I'm an amateur too..I just came into all these machines because I know people..and that is very fortunate for me. I'm also an inovator...and if I can use something for more then it was intended for...and save money/time...I'm all over it. The problem is grit distribution on your mirror...there are pleanty of ways to do it...and since nearly every machine out there is different to some degree..we have to create that is best suited for our needs and our situation.
A Coke bottle or any bottle for that matter would have worked. It needed to be big enough to hold enough grit..and small enough not to interfere with function.
Thanks for your fine comments and compliments.
Was the video easy to link?
Rob
--------------------
www.goldmtobservingcenter.com
A great place for amateur astronomers, and ATM's to come and enjoy their hobby.
http://tech.groups.yahoo.com/group/HomemadeRefractorTelescopes/ My homemade refractor group.
www.vimeo.com/6014031
|
droid
rocketman
Reged: 08/29/04
Posts: 4046
Loc: ohio
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Rob; I actually stickied your videos o my favorites tool bar ,one click and I can watch them again and again.
If you do more maybe you could explain why your doing what ever it is you are doing, could be an invaluable tool for some one else down the road.
Im excited just watching the progress , thanks ohhh so very much.
--------------------
12 inch Truss Reflector "John"
102mm Celestron C102HD
Tasco 7TE5 60mm Classic
Tasco 9TE5 60mm Classic
Celestron Ultima 2000 SCT
Remains of an 8 inch dob
Celestron Comet catcher(orange tube)
1960 Edscorp Space Conquerer 6inch f/8
10x50 Bushnell Binoculars.
11T 4.5 inch Tasco reflector Lunograsso?
60mm Telescope Club
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rwiederrich
Goldfinger
Reged: 11/17/05
Posts: 8334
Loc: Bremerton Washington
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Quote:
Rob; I actually stickied your videos o my favorites tool bar ,one click and I can watch them again and again.
If you do more maybe you could explain why your doing what ever it is you are doing, could be an invaluable tool for some one else down the road.
Im excited just watching the progress , thanks ohhh so very much.
Yes......when I shot that I was namely after documenting the new grit applicator...not describing what I was doing.
I will next time I make a video for the mirror.
I'll do it with mor production thinking in mind....
It was also an experiment to see if I could get a video up and running too.
Thanks for bringing that to my attention .
Rob(more will follow)
--------------------
www.goldmtobservingcenter.com
A great place for amateur astronomers, and ATM's to come and enjoy their hobby.
http://tech.groups.yahoo.com/group/HomemadeRefractorTelescopes/ My homemade refractor group.
www.vimeo.com/6014031
|
rwiederrich
Goldfinger
Reged: 11/17/05
Posts: 8334
Loc: Bremerton Washington
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Quote:
so.........assuming a final focal length of around f/6 what size secondary will I need?
I haven't done the math currently..but probably a 1.5" secondary.
Rob
--------------------
www.goldmtobservingcenter.com
A great place for amateur astronomers, and ATM's to come and enjoy their hobby.
http://tech.groups.yahoo.com/group/HomemadeRefractorTelescopes/ My homemade refractor group.
www.vimeo.com/6014031
|
droid
rocketman
Reged: 08/29/04
Posts: 4046
Loc: ohio
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1.5 it is
--------------------
12 inch Truss Reflector "John"
102mm Celestron C102HD
Tasco 7TE5 60mm Classic
Tasco 9TE5 60mm Classic
Celestron Ultima 2000 SCT
Remains of an 8 inch dob
Celestron Comet catcher(orange tube)
1960 Edscorp Space Conquerer 6inch f/8
10x50 Bushnell Binoculars.
11T 4.5 inch Tasco reflector Lunograsso?
60mm Telescope Club
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droid
rocketman
Reged: 08/29/04
Posts: 4046
Loc: ohio
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Rob; hey off topic here ...forthis thread....but I found this sight you might be interested in.
http://www.acquerra.com.au/astro/cooling/index.html
--------------------
12 inch Truss Reflector "John"
102mm Celestron C102HD
Tasco 7TE5 60mm Classic
Tasco 9TE5 60mm Classic
Celestron Ultima 2000 SCT
Remains of an 8 inch dob
Celestron Comet catcher(orange tube)
1960 Edscorp Space Conquerer 6inch f/8
10x50 Bushnell Binoculars.
11T 4.5 inch Tasco reflector Lunograsso?
60mm Telescope Club
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droid
rocketman
Reged: 08/29/04
Posts: 4046
Loc: ohio
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Just lookin in...errr well tryin to look in ...lol.
I know watching a mirror grind is kinda like watchin grass grow, you know whats happenin, but its so slow happenin.
--------------------
12 inch Truss Reflector "John"
102mm Celestron C102HD
Tasco 7TE5 60mm Classic
Tasco 9TE5 60mm Classic
Celestron Ultima 2000 SCT
Remains of an 8 inch dob
Celestron Comet catcher(orange tube)
1960 Edscorp Space Conquerer 6inch f/8
10x50 Bushnell Binoculars.
11T 4.5 inch Tasco reflector Lunograsso?
60mm Telescope Club
|
rwiederrich
Goldfinger
Reged: 11/17/05
Posts: 8334
Loc: Bremerton Washington
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Quote:
Just lookin in...errr well tryin to look in ...lol.
I know watching a mirror grind is kinda like watchin grass grow, you know whats happenin, but its so slow happenin.
Kinda like that.
I came across an issue with your blank..and I think there is some stress issues with it. After fine grinding last night I noticed some strange striations on the surface of the glass. To my knowlwedge I didn't create them. They kinda look like flakes of crystal. It's wierd.
Anyway I did a polarizing check to see if there is any internal stress in the blank. From what I gather I should see a pretty grey image...if stress is present it looks like chromatic reflections. Almost like a prism across the glass surface. I didn't know what to expect...but I saw this on the sagittal side and on the backside. Now I'm calling on all the mirror gurus and experts to interpret just what exactly I'm seeing. Doesn't look like any stress reflections I have ever seen.
These annealing stress test images were done using an adjustible polarising filter.
This first images is the *inside* image.
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www.goldmtobservingcenter.com
A great place for amateur astronomers, and ATM's to come and enjoy their hobby.
http://tech.groups.yahoo.com/group/HomemadeRefractorTelescopes/ My homemade refractor group.
www.vimeo.com/6014031
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rwiederrich
Goldfinger
Reged: 11/17/05
Posts: 8334
Loc: Bremerton Washington
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This is the backside *outside* image.
You can see the chromatic reflections.
This is stress.
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www.goldmtobservingcenter.com
A great place for amateur astronomers, and ATM's to come and enjoy their hobby.
http://tech.groups.yahoo.com/group/HomemadeRefractorTelescopes/ My homemade refractor group.
www.vimeo.com/6014031
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rwiederrich
Goldfinger
Reged: 11/17/05
Posts: 8334
Loc: Bremerton Washington
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And this is the *inside* image taken from the sagittal surface.
Personally...I'm not sure of the stress level of this blank...nor do these reading. tell me anything I can interpret.
I'm ready to go to the next grit..about 32 micron..but wanted to stress test this blank first.
So can any of the testing experts lend a hand?
Rob
--------------------
www.goldmtobservingcenter.com
A great place for amateur astronomers, and ATM's to come and enjoy their hobby.
http://tech.groups.yahoo.com/group/HomemadeRefractorTelescopes/ My homemade refractor group.
www.vimeo.com/6014031
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rwiederrich
Goldfinger
Reged: 11/17/05
Posts: 8334
Loc: Bremerton Washington
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Lastly...I checked to see if somehow I was inducing the internal images...and could find no source. These images are showing the internal stresses and striations and demarcation of the glass matrix. At least that is what I believe...till an expert tells me otherwise.
The regularity of the striations tends to cause me to believe they are not a real issue to the final figure or finish of the mirror....however....I need more information.
Rob 
--------------------
www.goldmtobservingcenter.com
A great place for amateur astronomers, and ATM's to come and enjoy their hobby.
http://tech.groups.yahoo.com/group/HomemadeRefractorTelescopes/ My homemade refractor group.
www.vimeo.com/6014031
|
rwiederrich
Goldfinger
Reged: 11/17/05
Posts: 8334
Loc: Bremerton Washington
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I went out to the shop and again did some testing. I first put my 17" up to the test and..bamn..nice grey surface..no shadows of chromatisizm or striations. Free from any stress...as it aught to be since it was well annealed.
Now back to the 12.5" I tested it again..even rotated it and the images got worse... Strands reaching all over the mirror surface...bright chromatic hues.
Now from what I gather, and what I know about the subject...*this aint' right*. I could be missing something very obvious...so I retain opinion till I heard from Mark..or one of the other experts.
Rob
--------------------
www.goldmtobservingcenter.com
A great place for amateur astronomers, and ATM's to come and enjoy their hobby.
http://tech.groups.yahoo.com/group/HomemadeRefractorTelescopes/ My homemade refractor group.
www.vimeo.com/6014031
|
droid
rocketman
Reged: 08/29/04
Posts: 4046
Loc: ohio
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Hmmmm I knew I was in over my head.....but wow , now Ive drug you down with me...
Im really sorry.....honest.
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12 inch Truss Reflector "John"
102mm Celestron C102HD
Tasco 7TE5 60mm Classic
Tasco 9TE5 60mm Classic
Celestron Ultima 2000 SCT
Remains of an 8 inch dob
Celestron Comet catcher(orange tube)
1960 Edscorp Space Conquerer 6inch f/8
10x50 Bushnell Binoculars.
11T 4.5 inch Tasco reflector Lunograsso?
60mm Telescope Club
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rwiederrich
Goldfinger
Reged: 11/17/05
Posts: 8334
Loc: Bremerton Washington
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Quote:
Hmmmm I knew I was in over my head.....but wow , now Ive drug you down with me...
Im really sorry.....honest.
That's not a problem Andy. It is very important we know the stress of the blank we are working on....cuz figuring it will be a nightmare...or once done the stress will faulsify the figure and leave you with a pretty useless mirror.
I got a call out to Mark for some professional advice. He'll chime in soon I'm sure.
So.......if this falls through...don't feal bad...this is what I'll do...I'll cut you a 13" blank from my stock. and we can begin again.....
I know what this particular blank meant to you...but if it's too stressed....I'm not wasting my time on it. I'll let my students use it to practice on.
We'll wait on the pros for the final word....K?
So what do you think of seeing *Inside* your blank?
Kinda cool huh? The double pass polarizing reveals the stress.
Rob
--------------------
www.goldmtobservingcenter.com
A great place for amateur astronomers, and ATM's to come and enjoy their hobby.
http://tech.groups.yahoo.com/group/HomemadeRefractorTelescopes/ My homemade refractor group.
www.vimeo.com/6014031
|
droid
rocketman
Reged: 08/29/04
Posts: 4046
Loc: ohio
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looked like it was poured in a waffle iron....ooops no one uses waffle irons nowadays ,I keep forgetting...again sorry.
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12 inch Truss Reflector "John"
102mm Celestron C102HD
Tasco 7TE5 60mm Classic
Tasco 9TE5 60mm Classic
Celestron Ultima 2000 SCT
Remains of an 8 inch dob
Celestron Comet catcher(orange tube)
1960 Edscorp Space Conquerer 6inch f/8
10x50 Bushnell Binoculars.
11T 4.5 inch Tasco reflector Lunograsso?
60mm Telescope Club
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rwiederrich
Goldfinger
Reged: 11/17/05
Posts: 8334
Loc: Bremerton Washington
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Quote:
looked like it was poured in a waffle iron....ooops no one uses waffle irons nowadays ,I keep forgetting...again sorry.
Yeah...but once I rotated the mirror the pattern changed to less regular formations...more like phsycodelac...giberish.
I again tested an 8" blank just to see and it was clean of stress. Strange images for sure... turn off the polarized light and turn on the overheads and all is clear and well again. Stress is a deceptive assassin...hiding till you least expect it....then...BAMN!
Sorry...I get excited now and again.
Rob (Mark..were you is?)
--------------------
www.goldmtobservingcenter.com
A great place for amateur astronomers, and ATM's to come and enjoy their hobby.
http://tech.groups.yahoo.com/group/HomemadeRefractorTelescopes/ My homemade refractor group.
www.vimeo.com/6014031
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