rwiederrich
Goldfinger
Reged: 11/17/05
Posts: 8683
Loc: Bremerton Washington
|
|
Quote:
Rob; in the last photo above, there is a small scope, haning seemingly on the wall, on what appears to be a single arm mount, 4.5 inch???
You are correct. That is a 1950's Laffaette reflector with a helical focuser...and very nice optics I might add. On a homemade single arm Alt/az mount with elevation adjustment.
This is the resting place for this scope when it is not mounted on its cement pier out on the scope field here at GOMOC.
After getting home from a dental convention today...I went out and began grinding on your 3rd attempt mirror.... 
Probably should change the thread title to reflect the current situation.. 
The finish is very fine and now I'm working on a 1/4" of the edge to bring it into the sphere...so I set the machine up to work the edge with roughly 1/3 tool overhang during the stroke. Lots of grit and minimal water drip.
Once the edge's worked on for a session(1.5hrs), I will set up for a cross stroke to blend zones...then back at the edge setup. I'll repeat this repetition back and forth for several sessions.
However....the initial hogging went well because I used a smaller diamond blade(4") to hog out the sagitta....instead of the 9" blade. This gave me a nice curface to begin grinding with.
I have dental convention tomorrow as well...but will work on your mirror when I return as well...maybe around 2:00 pm.
I'll put in some time tomorrow and my hope is to be ready for 12 micron early this coming week.
The edge of the mirror is waay better then the last one....there are some edge chips on the back...but compared to your original blank and the last one I cut out...its nice...r.
Sad to say...  ..but this last mirror nightmare caused me to re-evaluate some of my techniques and I am glad I was able to make some changes for the better.
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: 4258
Loc: ohio
|
|
soooo................are you getting to the "root " of the problem at these conventions????
Ive got a good feeling about this mirror , Ive already asked about finding 14inch tubing ,minimum, in another thread, will worry about spiders and cells and such until such time as I can afford ot buy them or I fall into them,lol
Still like your set up there in your shop.
I have an early/mid 1980 Tasco 4.5 inch reflector that gives sweet images, but its mount is a travesty,lol.
You ever post images for how you made the single arm mount?
--------------------
12 inch Truss Reflector "John"
102mm Celestron C102HD " Carl "
Tasco 7TE5 60mm Classic
Tasco 9TE5 60mm Classic
Celestron Ultima 2000 SCT "Wilma"
Celestron Comet catcher(orange tube)
1960 Edscorp Space Conquerer 6inch f/8
10x50 Bushnell Binoculars.
60mm Telescope Club
|
rwiederrich
Goldfinger
Reged: 11/17/05
Posts: 8683
Loc: Bremerton Washington
|
|
Quote:
soooo................are you getting to the "root " of the problem at these conventions????
Ive got a good feeling about this mirror , Ive already asked about finding 14inch tubing ,minimum, in another thread, will worry about spiders and cells and such until such time as I can afford ot buy them or I fall into them,lol
Still like your set up there in your shop.
I have an early/mid 1980 Tasco 4.5 inch reflector that gives sweet images, but its mount is a travesty,lol.
You ever post images for how you made the single arm mount?
Not on these pages....it was made years ago. Kinda nifty actually. It is hollow and three sides of the four sided arm were built around a wooden core. These 3 sides were formed to fit the mood core exactly....welded together...when all was good..the core was removed and the fourth side was welded on and the whole thing was finished. It's something to see.
Images of it are floating around CN somewhere.....
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: 4258
Loc: ohio
|
|
okie dokie then ....a 14inch tube is not going to be easy,lol.
Time to rethink, truss tube???
hows the feline problems working out, air horms working?
--------------------
12 inch Truss Reflector "John"
102mm Celestron C102HD " Carl "
Tasco 7TE5 60mm Classic
Tasco 9TE5 60mm Classic
Celestron Ultima 2000 SCT "Wilma"
Celestron Comet catcher(orange tube)
1960 Edscorp Space Conquerer 6inch f/8
10x50 Bushnell Binoculars.
60mm Telescope Club
|
rwiederrich
Goldfinger
Reged: 11/17/05
Posts: 8683
Loc: Bremerton Washington
|
|
Quote:
okie dokie then ....a 14inch tube is not going to be easy,lol.
Time to rethink, truss tube???
hows the feline problems working out, air horms working?
It's been raining and the beasts are in the house. Soon as I walk in the shop I shut the door behind me(looking for kitties as I do). Back to grinding today.
I haven't heard from the fellow who wanted a 13" mirror blank from me about a month ago...and so I'm thinking of putting that blank on the grinder and hogging it out as well. I'm needing a 13" for the Cincinnatti mill pier I've been working on too....so I might do that if I don't hear from this gentleman like soom.
Grinding..grinding today.
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: 8683
Loc: Bremerton Washington
|
|
Well..lots of stuff going on today.
2 things of importance.
I spent lots of time working the edge....and blending and I have the edge done I believe. I took these pictures prior to the final sessions of edge and blend. I'm pretty happy the over all surface is nice and even and finely frosted...no scratches at all. Edge 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: 8683
Loc: Bremerton Washington
|
|
Fine ground mirror from top....
--------------------
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: 8683
Loc: Bremerton Washington
|
|
After I took the pic..I tooled up for more edge grinding and subsiquently full width blending.
That is done now...and probably tomorrow afternoon I will begin 12 micron fine grinding...that won't take long...I'm sure. I built the polishing tool/lap already and when ready...will soften the pitch in warm water and press it on the mirror...channel it...repress and then begin polishing.
The second thing is...students came buy and we made the pitch polishing tool for that 8". And put a flash polish on the mirror so see what it looks like.
Here are some pix of the process..
First we heated and melted pitch on the stove.....
--------------------
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: 8683
Loc: Bremerton Washington
|
|
I took a 4" aluminum tool and damed it with tape to hold the pitch.
--------------------
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: 8683
Loc: Bremerton Washington
|
|
Then we took a pre made aluminum mold...coated with polishing slurry and pressed the warm pitch into it to form the channels and make the familiar polishing tool....
--------------------
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: 8683
Loc: Bremerton Washington
|
|
After this I quickly applied some slurry to the already set mirror and pressed it onto the mirror to form the curve to the newly channeled polisher.
--------------------
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: 8683
Loc: Bremerton Washington
|
|
The mirror students were amazed I took the time to fine grind the mirror for them.....It realy saved us time in the long run.
Here we set the machine up with the polishing tool in place and polishing commenced...
--------------------
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: 8683
Loc: Bremerton Washington
|
|
This went on for about an hour...and we spent time chatting and cleaning up around the shop. We then popped the tool off so we could see the progress....it was polishing nicely(It was moving along faster then I had hoped). Here is a pic of the tool next to the mirror on the table.
--------------------
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: 8683
Loc: Bremerton Washington
|
|
Well....this was fun..but everyone had to leave..they were going to the fair....and just popped in on their way.
Well since we did a flash polish I wanted to see what shape the mirro was in..so I mounted it on the test stand and tested it. The mirror I had placed the day earlier worked very well....I was able to locate the mirror fast by watching the reflection of the video monitor....Once found and roughly aligned..I walked back to the tested and fine tuned the image.
WOW! This mirror is still very rough. Even though you can see a farely nice polish on the surface.....it is far from anything I would consider close to being done.
Here are some images of the video monitor.
--------------------
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: 8683
Loc: Bremerton Washington
|
|
Doing a KE test and a shadowgram you can see a donut in the middle.
--------------------
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: 8683
Loc: Bremerton Washington
|
|
I would welcome any and all evalutions of this particular mirror at this time...just to see what other mirror makers have to say for this particular mirrors correction and subsiquent evaluation.
I will probably shorted the stroke and focus on the center. Along with many other things.
Rob(been a fine day)
--------------------
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: 4258
Loc: ohio
|
|
wow it went way faster this time , nearly polishing after only what a few days, sweeeeet.
In the first picture you can see the donut also, but as a slight darkening with a bright central peak, and a ighter outer ridg.
These images you show are cool.
--------------------
12 inch Truss Reflector "John"
102mm Celestron C102HD " Carl "
Tasco 7TE5 60mm Classic
Tasco 9TE5 60mm Classic
Celestron Ultima 2000 SCT "Wilma"
Celestron Comet catcher(orange tube)
1960 Edscorp Space Conquerer 6inch f/8
10x50 Bushnell Binoculars.
60mm Telescope Club
|
rwiederrich
Goldfinger
Reged: 11/17/05
Posts: 8683
Loc: Bremerton Washington
|
|
Quote:
wow it went way faster this time , nearly polishing after only what a few days, sweeeeet.
In the first picture you can see the donut also, but as a slight darkening with a bright central peak, and a ighter outer ridg.
These images you show are cool.
Thanks...Andy.
IT'S FUN....I'm kinda like an open book...I got no trade secrets to hide...or protect.
I'm sure the professionals would find lots of things wrong with my technique and approach.
I'm heading out to the shop now to begin fine grinding on your mirror...so hopefully we'll be testing it some time next week. Hopefully....
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
|
Spoonsize
Vendor/Clothing
Reged: 08/27/04
Posts: 3334
|
|
It would surely be interesting just to be able to play with this 8" setup. If I had the time, I'd wonder what it would look like if the stroke were changed to have a 1/4 tool overhang and polish all the way from one side to the other.
Rob....do you use red rouge to polish?
|
rwiederrich
Goldfinger
Reged: 11/17/05
Posts: 8683
Loc: Bremerton Washington
|
|
Quote:
It would surely be interesting just to be able to play with this 8" setup. If I had the time, I'd wonder what it would look like if the stroke were changed to have a 1/4 tool overhang and polish all the way from one side to the other.
Rob....do you use red rouge to polish?
Actually..no. I use Cerium. I have rouge. and was going to make my own slurry...but lost energy to do so.
I worked that 8" some more and was able to soften that *donut* quite a bit. However the surface is still rough enough that I might go back to fine grinding to clean it up and really take down that donut...then back to polishing.
Andy's finished up last night with good results. Nice finely soft frosting with no scratches at all.
I'll probably run it a bit more today just to be sure before I begin hot pressing the polishing tool for polishing.
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
|
bgilb
member
Reged: 07/05/09
Posts: 79
|
|
That shadowgram is the most interesting shape. TUE, followed by a mount of oblateness, followed by a hole, followed by the most crisp cylindrical hill I've ever seen. It should all be easily fixed though.
|
droid
rocketman
Reged: 08/29/04
Posts: 4258
Loc: ohio
|
|
Rob ...dumb question alert
" Actually..no. I use Cerium. I have rouge. and was going to make my own slurry...but lost energy to do so."
whats the differance between Cerium and rouge ??? if any ?
--------------------
12 inch Truss Reflector "John"
102mm Celestron C102HD " Carl "
Tasco 7TE5 60mm Classic
Tasco 9TE5 60mm Classic
Celestron Ultima 2000 SCT "Wilma"
Celestron Comet catcher(orange tube)
1960 Edscorp Space Conquerer 6inch f/8
10x50 Bushnell Binoculars.
60mm Telescope Club
|
neo
professor emeritus
Reged: 02/12/08
Posts: 724
Loc: Iasi, Romania
|
|
With Cerium you can polish faster and much cleaner but for the best optics rouge is your friend. It gives the best polish, the glass surface is very smooth. And for even more ambitious results the rouge can be milled for an even finer surface. The downside is that is very messy and polish slowly than other compounds.
--------------------
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
|
rwiederrich
Goldfinger
Reged: 11/17/05
Posts: 8683
Loc: Bremerton Washington
|
|
Quote:
With Cerium you can polish faster and much cleaner but for the best optics rouge is your friend. It gives the best polish, the glass surface is very smooth. And for even more ambitious results the rouge can be milled for an even finer surface. The downside is that is very messy and polish slowly than other compounds.
Indeed..I just fine wet ground some red rouge and filled a 2 gallon drum with it.
I will let the heavy particles settle and scim off the water and begin to seporate the particles.
Yes..indeed..rouge is extremely messy and stains everything....I will try my new batch on a recently fine ground 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: 4258
Loc: ohio
|
|
Have you made the tool thingy , with the grooves in it made already?
--------------------
12 inch Truss Reflector "John"
102mm Celestron C102HD " Carl "
Tasco 7TE5 60mm Classic
Tasco 9TE5 60mm Classic
Celestron Ultima 2000 SCT "Wilma"
Celestron Comet catcher(orange tube)
1960 Edscorp Space Conquerer 6inch f/8
10x50 Bushnell Binoculars.
60mm Telescope Club
|
rwiederrich
Goldfinger
Reged: 11/17/05
Posts: 8683
Loc: Bremerton Washington
|
|
Quote:
Have you made the tool thingy , with the grooves in it made already?
The polishing tool...or as it is know as....the pitch lap..Yes. It is made and will be hot pressed onto the mirror when I'm satisfied with its fine grinding.
I will probably fine grind with 9 micron first.
I've only reached fine grinding with 12 micron...probably not smooth enough...and will take waaay to long to polish.
From what I gather a good test is when you can easily read large newspaper print through the 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: 4258
Loc: ohio
|
|
Hey this is exciting weve ( you've ) not gotten this close before ....hehehehehehehehehe.
I swear if any one ever takes the time to read over this thread...wow.
Bad glass, bad cats, bad luck.... 
--------------------
12 inch Truss Reflector "John"
102mm Celestron C102HD " Carl "
Tasco 7TE5 60mm Classic
Tasco 9TE5 60mm Classic
Celestron Ultima 2000 SCT "Wilma"
Celestron Comet catcher(orange tube)
1960 Edscorp Space Conquerer 6inch f/8
10x50 Bushnell Binoculars.
60mm Telescope Club
|
rwiederrich
Goldfinger
Reged: 11/17/05
Posts: 8683
Loc: Bremerton Washington
|
|
Quote:
Hey this is exciting weve ( you've ) not gotten this close before ....hehehehehehehehehe.
I swear if any one ever takes the time to read over this thread...wow.
Bad glass, bad cats, bad luck....
Well..it's a very steap learning curve...when one needs to take into account...bad glass..bad cats..and bad luck.
1)....I fixed the bad glass thing. 1 point for me
2)....I fixed the bad kitty thing. 2 points for me
3)....fixing the bad luck thing with prayer. 3 points
Hopefully the earth won't open up and suck my whole shop into it next.....
I bet every amateur...not to mention professional mirror maker has their own nightmare stories.
Everyone here just gets to read about mine....cuz I'm stupid and I post it.....
I've learned a few things using these machines...and one of them is to leave the mirror on the table till testing....and continue to create a randomness in the stroke..ie..edge then full sweep..then back to edge...etc.
I've worked out my video monitor system with my foucault/rochi tester..which will help in your mirror testing and figuring.
So..all those bad things do actually have fruit produced from them. It just never feels like it at the moment.
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: 8683
Loc: Bremerton Washington
|
|
Quote:
Hey this is exciting weve ( you've ) not gotten this close before ....hehehehehehehehehe.
I swear if any one ever takes the time to read over this thread...wow.
Bad glass, bad cats, bad luck....
It's also a good testiment to the expeditiousness of replacing what was lost. First replacing your bad glass...then replacing the severely damaged mirror with a newly cut one..hogging..and fine grinding. It has all happened relatively quickly...I think. Learning the machines...while heavily modifying them and grinding a mirror at the same time can be daunting...not to mention inventing drip systems...grit despensing systems...etc.
It's been real fun fer sure.
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
|
droid
rocketman
Reged: 08/29/04
Posts: 4258
Loc: ohio
|
|
Quote:
Hopefully the earth won't open up and suck my whole shop into it next.....
Rob
Tell me you knocked on wood, threw salt over your shoulder, after typing that ... 
--------------------
12 inch Truss Reflector "John"
102mm Celestron C102HD " Carl "
Tasco 7TE5 60mm Classic
Tasco 9TE5 60mm Classic
Celestron Ultima 2000 SCT "Wilma"
Celestron Comet catcher(orange tube)
1960 Edscorp Space Conquerer 6inch f/8
10x50 Bushnell Binoculars.
60mm Telescope Club
|
rwiederrich
Goldfinger
Reged: 11/17/05
Posts: 8683
Loc: Bremerton Washington
|
|
Quote:
Quote:
Hopefully the earth won't open up and suck my whole shop into it next.....
Rob
Tell me you knocked on wood, threw salt over your shoulder, after typing that ...
Is that sink hole evasion tactics..... 
If it's gonna happen its gonna happen to me..
I'm putting together some more aluminum polishing tools...a couple of 5~6" ones. I plan on using one for your mirror in conjunction with the full size polisher. I'll need it to figure.
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: 4258
Loc: ohio
|
|
Once your at the polishing stage,your looking at what?? a week? or so? I dunno,just womderin,lol.
Any new photos to tease me with
And honestly I do miss your dern videos, them was cool. 
--------------------
12 inch Truss Reflector "John"
102mm Celestron C102HD " Carl "
Tasco 7TE5 60mm Classic
Tasco 9TE5 60mm Classic
Celestron Ultima 2000 SCT "Wilma"
Celestron Comet catcher(orange tube)
1960 Edscorp Space Conquerer 6inch f/8
10x50 Bushnell Binoculars.
60mm Telescope Club
|
Spoonsize
Vendor/Clothing
Reged: 08/27/04
Posts: 3334
|
|
"I bet every amateur...not to mention professional mirror maker has their own nightmare stories", Rob.
Like most ATM's, when it came time to begin testing my first mirror, a 6"f/8, I built my knife edge tester. I followed the directions in Sam Brown's "All About Telescopes", an ATM guide. I made use of a single edge razor blade for the knife edge.
I found when using the tester that I could get a better view of the surface shadows when I got my eye closer to the knife edge. Towards the end of polishing, I found the shadow to be closer to the final desired shape than ever before, got very excited, turned to stand up too quick and found the knife edge slicing the side of my nose. Painful, yes, but even at the time it was too funny to keep me from laughing.
|
droid
rocketman
Reged: 08/29/04
Posts: 4258
Loc: ohio
|
|
Quote:
"I bet every amateur...not to mention professional mirror maker has their own nightmare stories", Rob.
Like most ATM's, when it came time to begin testing my first mirror, a 6"f/8, I built my knife edge tester. I followed the directions in Sam Brown's "All About Telescopes", an ATM guide. I made use of a single edge razor blade for the knife edge.
I found when using the tester that I could get a better view of the surface shadows when I got my eye closer to the knife edge. Towards the end of polishing, I found the shadow to be closer to the final desired shape than ever before, got very excited, turned to stand up too quick and found the knife edge slicing the side of my nose. Painful, yes, but even at the time it was too funny to keep me from laughing.
just a little to nosey for your own good....
Well if youve read this thread, youll see I sent the poor guy a peice of uhum....glass.
He agreed to make me a mirror,all I can say is it was pretty in a warped sort of way when he tested it for stress.
--------------------
12 inch Truss Reflector "John"
102mm Celestron C102HD " Carl "
Tasco 7TE5 60mm Classic
Tasco 9TE5 60mm Classic
Celestron Ultima 2000 SCT "Wilma"
Celestron Comet catcher(orange tube)
1960 Edscorp Space Conquerer 6inch f/8
10x50 Bushnell Binoculars.
60mm Telescope Club
|
rwiederrich
Goldfinger
Reged: 11/17/05
Posts: 8683
Loc: Bremerton Washington
|
|
Quote:
Once your at the polishing stage,your looking at what?? a week? or so? I dunno,just womderin,lol.
Any new photos to tease me with
And honestly I do miss your dern videos, them was cool.
In theory...I guess a week might be right...however..I do have a wife..who does require of me now and again...and so being just a *Hobby* I have to play it safe. I'll definately keep you updated for sure and I'll post lots of pix 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: 8683
Loc: Bremerton Washington
|
|
Quote:
"I bet every amateur...not to mention professional mirror maker has their own nightmare stories", Rob.
Like most ATM's, when it came time to begin testing my first mirror, a 6"f/8, I built my knife edge tester. I followed the directions in Sam Brown's "All About Telescopes", an ATM guide. I made use of a single edge razor blade for the knife edge.
I found when using the tester that I could get a better view of the surface shadows when I got my eye closer to the knife edge. Towards the end of polishing, I found the shadow to be closer to the final desired shape than ever before, got very excited, turned to stand up too quick and found the knife edge slicing the side of my nose. Painful, yes, but even at the time it was too funny to keep me from laughing.
When I built my KE I used thin galvanized steal and I ground a very sharp edge on it...I then fixed a double edged blade similar to yours to see if there was any difference between the 2. NOPE..the nice clean edge on the metal one I made was just as clean and sharp as the razor blade....so I removed the weapon from my tester.
Rob(razor cuts hurt)
--------------------
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: 8683
Loc: Bremerton Washington
|
|
Quote:
Quote:
"I bet every amateur...not to mention professional mirror maker has their own nightmare stories", Rob.
Like most ATM's, when it came time to begin testing my first mirror, a 6"f/8, I built my knife edge tester. I followed the directions in Sam Brown's "All About Telescopes", an ATM guide. I made use of a single edge razor blade for the knife edge.
I found when using the tester that I could get a better view of the surface shadows when I got my eye closer to the knife edge. Towards the end of polishing, I found the shadow to be closer to the final desired shape than ever before, got very excited, turned to stand up too quick and found the knife edge slicing the side of my nose. Painful, yes, but even at the time it was too funny to keep me from laughing.
just a little to nosey for your own good....
Well if youve read this thread, youll see I sent the poor guy a peice of uhum....glass.
He agreed to make me a mirror,all I can say is it was pretty in a warped sort of way when he tested it for stress.
I think you sent me an airplane cabin window.....tempered for high pressure...
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: 4258
Loc: ohio
|
|
nahhh......porthole from a boat is possible I guess since he worked at the marina, once upon a time.
But no airplane parts.
ohhh you were joking,
--------------------
12 inch Truss Reflector "John"
102mm Celestron C102HD " Carl "
Tasco 7TE5 60mm Classic
Tasco 9TE5 60mm Classic
Celestron Ultima 2000 SCT "Wilma"
Celestron Comet catcher(orange tube)
1960 Edscorp Space Conquerer 6inch f/8
10x50 Bushnell Binoculars.
60mm Telescope Club
|
rwiederrich
Goldfinger
Reged: 11/17/05
Posts: 8683
Loc: Bremerton Washington
|
|
Quote:
nahhh......porthole from a boat is possible I guess since he worked at the marina, once upon a time.
But no airplane parts.
ohhh you were joking,
I didn't mention the porthole...cuz folks have been using them for years to make mirrors and they generally aren't tempered. The older ones anyway.
Yesterday was a family day and I shut the shop down to spend time with my girls. Today I'm going to try some softer fine grade ALOX on your mirror to see if I can bring the grind to what I'm looking for....but then again...the grind is nice right now and there are no scratches at all...anywere(I just don't want to induce any by accident)...so I might heat up the pitch and hot press the polisher to it in stead. I'm gonna be polishing for quite some time anyway....what's a bit more time to get it right.
I'm using a full size tool.
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: 8683
Loc: Bremerton Washington
|
|
Well I made two polishing tools today. I stunk up the office early this morning while melting pitch in the lunchroom kitchen....(Oooops).
I went to the lab and melted the pitch for the 13" tool.
I used the same tried and true method to make my tools and now they have been polishing the mirrors for an hour now.
I made a 5" for the 8" mirro as well.
I decided to go with Cerium instead of rouge this time round. Rough is just do nasty dirty.
Here are some pic for all of you who have been following.
Here is one of the polisher just about 10 minutes after it was set in motion.
--------------------
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: 8683
Loc: Bremerton Washington
|
|
Another view.....in the back is my jug full of cerium. It is kept suspended by the use of a simple fish tank *bubbler*.
I use the same bubbled for both water jugs...it works very slick...cost almost nothing and it keeps the cerium suspended. The slurry is simply dripped on via a small dental tube and simple capillary action gives me the right amount.
We call the cerium solution...*mouses milk*...cuz it has to be extremely thin.
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: 8683
Loc: Bremerton Washington
|
|
This view shows both mirrors getting polished.
I use about 20lbs of weight on both over arms of each mirror. The 8in is looking pretty good now.
I'll probably machine polish the 13in for about 20 hrs before I check it. My goal is not to remove the mirror from the table till the polish is sufficent enough for testing.
Here is that side view images. Note the MD...energy drink for anyone wanting to make mirrors..
--------------------
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: 8683
Loc: Bremerton Washington
|
|
Here is a close up of the 8". Drip drip drip.....mouses milk....
This will run as well for about 15 hours.
I just need to charge the jugs with more water and cerium powder.
Emails have been coming in....and it looks like I'm gonna be busy.....
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
|
rwiederrich
Goldfinger
Reged: 11/17/05
Posts: 8683
Loc: Bremerton Washington
|
|
Finishing up the day...I wanted to test the 8" again to see if we took down that donut in the center.....
We remove most if it...but the surface still isn't free from small scratches. it's still rough.
Here are some more video images of the mirror surface.
As you can see the donut is doing away...but I still have an edge that is raised. No problem...better then a TDE...any day.
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: 8683
Loc: Bremerton Washington
|
|
And one with ronchi grading in place to see the sphere...
This is behind the radius of curve.
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: 8683
Loc: Bremerton Washington
|
|
Now onto Droids mirror......
I took the tool off to clean it and check the progress (if any). I found I was not getting full contact in the center...No problem.
I'll repress tomorrow and then increase the stroke to give me 1/4 overhang to begin with. Then let it run for.....many..many hours.
It was a trouble free day..... 
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: 4258
Loc: ohio
|
|
Quote:
Now onto Droids mirror......
I took the tool off to clean it and check the progress (if any). I found I was not getting full contact in the center...No problem.
I'll repress tomorrow and then increase the stroke to give me 1/4 overhang to begin with. Then let it run for.....many..many hours.
It was a trouble free day.....
Rob
Rob ,thats so coool.after all the problems weve had ,youve endured, this is coming close to fruitiion.
Hey as an aside, and off topic, with all the fires ,seemingly, yearly.And now with one in Oregon, how is GOMOC? fire prone area? I worry a lot ...lol
--------------------
12 inch Truss Reflector "John"
102mm Celestron C102HD " Carl "
Tasco 7TE5 60mm Classic
Tasco 9TE5 60mm Classic
Celestron Ultima 2000 SCT "Wilma"
Celestron Comet catcher(orange tube)
1960 Edscorp Space Conquerer 6inch f/8
10x50 Bushnell Binoculars.
60mm Telescope Club
|
rwiederrich
Goldfinger
Reged: 11/17/05
Posts: 8683
Loc: Bremerton Washington
|
|
Quote:
Quote:
Now onto Droids mirror......
I took the tool off to clean it and check the progress (if any). I found I was not getting full contact in the center...No problem.
I'll repress tomorrow and then increase the stroke to give me 1/4 overhang to begin with. Then let it run for.....many..many hours.
It was a trouble free day.....
Rob
Rob ,thats so coool.after all the problems weve had ,youve endured, this is coming close to fruitiion.
Hey as an aside, and off topic, with all the fires ,seemingly, yearly.And now with one in Oregon, how is GOMOC? fire prone area? I worry a lot ...lol
Yeah.....polishing will most likely be the longest of all the processes......combined.
I can see where it takes some of these guys a year to provide a custom mirror....6 months is probably more realistic.
No fires here at GOMOC...to green currently 
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: 4258
Loc: ohio
|
|
6 months??? holy cow,lol.
Hey dumb question......as the mirror nears completion.Im planning the scope. Im reading the Kreige book, and on page 115 , on the making of an 18 point flotation cell, he shows a circle devided into 6 segments, with each having a triangle in it ,with each triangle having three contact points on it.
Im wondering , why the center is left unsupported?
Is this a non issue, dumb question, ??? lol
--------------------
12 inch Truss Reflector "John"
102mm Celestron C102HD " Carl "
Tasco 7TE5 60mm Classic
Tasco 9TE5 60mm Classic
Celestron Ultima 2000 SCT "Wilma"
Celestron Comet catcher(orange tube)
1960 Edscorp Space Conquerer 6inch f/8
10x50 Bushnell Binoculars.
60mm Telescope Club
|
rwiederrich
Goldfinger
Reged: 11/17/05
Posts: 8683
Loc: Bremerton Washington
|
|
Quote:
6 months??? holy cow,lol.
Hey dumb question......as the mirror nears completion.Im planning the scope. Im reading the Kreige book, and on page 115 , on the making of an 18 point flotation cell, he shows a circle devided into 6 segments, with each having a triangle in it ,with each triangle having three contact points on it.
Im wondering , why the center is left unsupported?
Is this a non issue, dumb question, ??? lol
If you add up all the time I spent finding out(discovering) that your original blank was an ashtray...and that cutting glass blanks can be less fun then eating spaghetti...combined with one catastrophy upon another....you might just be getting your mirror in that 6 month time frame........You know...from the first day you had the crazy thought to ask ME to make it for you....
The mirrors stress points are calculated and the center is equally divided between the zonal suports....thus the stresses are translated equally across the mirror. Sometimes the distance between the 3 contact points can be used as a guide for the distance to the center. Sometimes the distance from the outer 3 contacts is the same distance from the edge as it is from the center.
Some have gotten very elaborate in their designs.
An 18 point silocone contact floating cell will be way adequate for this mirror. If you are going to use it soley for an alt/az mount a wire sling will be needed. Some say a nylon strap sling is better...some say no. It's up to you. If it is for that ball scope that has an almost endless rotation then RTV the floating cell to the mirror and then you can rotate the mirror. That is my plan for my 17" f/6 project.
Good luck..
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: 4258
Loc: ohio
|
|
Rob; I still havent been able to wrap my remaining brain cells around the intricate plans for the ball scope.
And Im starting to like the classic "Obsession" more and more.
Of course thats just as intricate on some ways, Id love ot do a side walk astronomers type ,but have yet ot find a sonotube distributer that sells 14 inch plus tubing.
So in short the hole with no support in the middle is not a problem.?
" An 18 point silocone contact floating cell " 18 silicon blobs on a round disc?
--------------------
12 inch Truss Reflector "John"
102mm Celestron C102HD " Carl "
Tasco 7TE5 60mm Classic
Tasco 9TE5 60mm Classic
Celestron Ultima 2000 SCT "Wilma"
Celestron Comet catcher(orange tube)
1960 Edscorp Space Conquerer 6inch f/8
10x50 Bushnell Binoculars.
60mm Telescope Club
|
droid
rocketman
Reged: 08/29/04
Posts: 4258
Loc: ohio
|
|
Well another weekend is upon us, lol.And I finally get a weekend off, yay......oh well have a nice weekend.
--------------------
12 inch Truss Reflector "John"
102mm Celestron C102HD " Carl "
Tasco 7TE5 60mm Classic
Tasco 9TE5 60mm Classic
Celestron Ultima 2000 SCT "Wilma"
Celestron Comet catcher(orange tube)
1960 Edscorp Space Conquerer 6inch f/8
10x50 Bushnell Binoculars.
60mm Telescope Club
|
rwiederrich
Goldfinger
Reged: 11/17/05
Posts: 8683
Loc: Bremerton Washington
|
|
Quote:
Well another weekend is upon us, lol.And I finally get a weekend off, yay......oh well have a nice weekend.
Glad you get some time off......you need it.
Just polishing today...and mewing lawns and fixing car headlights. And polishing.
I hope to put in about 7 hours into the mirror today.
That will make it around 10 hours of polishing.
Aaand 20 to go..there abouts before I even think about testing it.
I'm so glad this isn't being done by 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
|
droid
rocketman
Reged: 08/29/04
Posts: 4258
Loc: ohio
|
|
ok....at this rate....youll be testing within a week?????
If you were doing it by hand how long would it have taken???
--------------------
12 inch Truss Reflector "John"
102mm Celestron C102HD " Carl "
Tasco 7TE5 60mm Classic
Tasco 9TE5 60mm Classic
Celestron Ultima 2000 SCT "Wilma"
Celestron Comet catcher(orange tube)
1960 Edscorp Space Conquerer 6inch f/8
10x50 Bushnell Binoculars.
60mm Telescope Club
|
rwiederrich
Goldfinger
Reged: 11/17/05
Posts: 8683
Loc: Bremerton Washington
|
|
Quote:
ok....at this rate....youll be testing within a week?????
If you were doing it by hand how long would it have taken???
I can't imagine by hand..actually. But it still takes eons of time..by hand or machine.
And yes..I hope to be testing in a week. I'm just about ready to go out and shut it down for the evening...that will mean it polished for just about 7 hours today.
Add that to the 2 hours the other day...and we have about 9 hours in. Remember..polish polish polish....Cerium is like thin milk...and you just can't rush this.....A perfectly polished sphere is the goal.
Then I will use the subdiameter polisher to hand figure on the Porter table(possibly). This takes time...because you need to let the mirror rest(cool) between sessions before testing...to allow the mirror to cool to ambient and permit it to expell heat generated by figuring.
Like I said earlier...this process can take as long or longer then the actual grinding of the mirror.
If youadd those things up....
I'm heading out and I'll take a pic that I'll post later of its current 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: 8683
Loc: Bremerton Washington
|
|
OK...I went out and took the polisher off the mirror...cleaned things up and we are making progress... Slowly but surely...
Here are some pics. The first is looking through the mirror at the carpet backing...the flash is the bright spot.
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: 8683
Loc: Bremerton Washington
|
|
Washing the mirror with clean water...I never rub the mirror to remove the water/particles.
Flush then wipe with very clean cotton cloth.
--------------------
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: 8683
Loc: Bremerton Washington
|
|
This one show the polish that is begining on the edge and rund about 1/3 inside the edge.
--------------------
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: 8683
Loc: Bremerton Washington
|
|
A bit better one...The surface still has lots of polishing to get done...but this is the beginning.
The camera doesn't do any justice to the real image....
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
|
Colm
journeyman
Reged: 09/16/09
Posts: 7
Loc: SW Washington State
|
|
Looking good, Rob.
That ball scope design is pretty nifty, but where would I find a ball to hold an 18" mirror? (Actually, I just went over to the Obsession site, and now I want a 25"! The production models only cost about 20X my monthly income, but I should be able to build one for half that. What's a little money for killer aperture, right?  )
Anyway, I think I'll stick to the trusty old dob design and forget about spheres.
(dreaming of the day I need to climb a ladder to look through the eyepiece...).
--------------------
--James
Orion Astroview 6 EQ Newt
Orion XT8 Classic Dob
14" Home built Dob in planning
Two Eyes
|
droid
rocketman
Reged: 08/29/04
Posts: 4258
Loc: ohio
|
|
Colm; Im hopeing I wont need a ladder for this scope.AT f/5 itll be just a hair over 5 feet focal length.
Stand on the ground heigth.
--------------------
12 inch Truss Reflector "John"
102mm Celestron C102HD " Carl "
Tasco 7TE5 60mm Classic
Tasco 9TE5 60mm Classic
Celestron Ultima 2000 SCT "Wilma"
Celestron Comet catcher(orange tube)
1960 Edscorp Space Conquerer 6inch f/8
10x50 Bushnell Binoculars.
60mm Telescope Club
|
droid
rocketman
Reged: 08/29/04
Posts: 4258
Loc: ohio
|
|
see the basic info thread for more on the scopes specifics
--------------------
12 inch Truss Reflector "John"
102mm Celestron C102HD " Carl "
Tasco 7TE5 60mm Classic
Tasco 9TE5 60mm Classic
Celestron Ultima 2000 SCT "Wilma"
Celestron Comet catcher(orange tube)
1960 Edscorp Space Conquerer 6inch f/8
10x50 Bushnell Binoculars.
60mm Telescope Club
|
Colm
journeyman
Reged: 09/16/09
Posts: 7
Loc: SW Washington State
|
|
Droid,
I didn't say you were dreaming of that day, but that I was. 
However, I am considering trying to built a 13" f/5 myself. A Discovery/Obsession style Dob. I did have my heart set on about an 18" (small ladder at zenith scope), but decided that is probably biting off more than I can chew, considering this would be my first time building a scope, and that I am chronically ill and need to be able to move it around.
A 13" is definitely a step up from an 8" anyway.
I wish you the best on your project. I think you're in good hands with Rob.
--------------------
--James
Orion Astroview 6 EQ Newt
Orion XT8 Classic Dob
14" Home built Dob in planning
Two Eyes
|
droid
rocketman
Reged: 08/29/04
Posts: 4258
Loc: ohio
|
|
Colm; yeah I have a feeling the 13 inch will be my upper limit as well, I currenly have an 8 inch dob ,I throw it on my shoulder and carry it, the 13 inch wont be that easy,lol.
Diabetes, bad feet and back make this my last aperature jump,probably.
Im positive Im in good hands with Rob, its my hand once the mirrors done I don't trust,
--------------------
12 inch Truss Reflector "John"
102mm Celestron C102HD " Carl "
Tasco 7TE5 60mm Classic
Tasco 9TE5 60mm Classic
Celestron Ultima 2000 SCT "Wilma"
Celestron Comet catcher(orange tube)
1960 Edscorp Space Conquerer 6inch f/8
10x50 Bushnell Binoculars.
60mm Telescope Club
|
rwiederrich
Goldfinger
Reged: 11/17/05
Posts: 8683
Loc: Bremerton Washington
|
|
James...thank you so very much.
I'm putting my best foot forward.
I can tool up that new 13" and begin hogging it out as soon as you give me the word........
This means I need to cut out some more blanks...for everyone else....
Better git on 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
|
droid
rocketman
Reged: 08/29/04
Posts: 4258
Loc: ohio
|
|
Quote:
Better grit on that.
Rob
--------------------
12 inch Truss Reflector "John"
102mm Celestron C102HD " Carl "
Tasco 7TE5 60mm Classic
Tasco 9TE5 60mm Classic
Celestron Ultima 2000 SCT "Wilma"
Celestron Comet catcher(orange tube)
1960 Edscorp Space Conquerer 6inch f/8
10x50 Bushnell Binoculars.
60mm Telescope Club
|
rwiederrich
Goldfinger
Reged: 11/17/05
Posts: 8683
Loc: Bremerton Washington
|
|
Quote:
Quote:
Better grit on that.
Rob
As *true* as it gets....
I had a friend come over today and I gave him an extensive tour of my shops and mirror making outfit....I then fired up your mirror and gave him a class on grinding...pitch lap making...and worked our way over to the tester and I showed him how to test a mirror. I placed a couder mask on the 8" and showed him how to find zonal error and nulls.
We then went over to my machine shop and I repaired a poorly treated crayford focuser he has on his 12.5" newt.
The machined recess that the knob axle rides against was filed quite uneven...so it bound up all the time.
We simply removed the focuser draw tube and I leveled and squared it up on the mill and I milled it all flat again for him....Slick as butter and very smooth now.
He traded me about a dozen 4ft box angle channel plates. Super ATMing stuff for sure
About 20 minutes ago I shut the polisher down and cleaned things up...your mirror is coming along nicely. I will off set the stroke tomorrow to begin pulling in the center to the edge. Funny how these things polish out...sometime they polish from the edge in and sometimes from the center out. It's like a box of chocolates....ya never know what's your gonna get. 
Na... just kidding...I do know what I'm getting..
Rob(tired and I gots to git to beddy by) 
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
|
BradleyB
sage
Reged: 09/01/06
Posts: 300
Loc: Olympia, WA
|
|
Rob did give me a tour of his great shop. I saw first hand how mirrors are made and tested. It cleared up a lot of questions I had about the subject. Rob was being nice and discreet about just who messed up my focuser, it was I who filed the flat in an effort to increase friction between the roller and focuser tube. It actually did help in that regard, but as Rob mentioned it was not very flat so it bound up and had uneven motion. Now that Rob has machined it flat it looks and works very much better. Thanks Rob for the tour and work, I appreciate it.
Droid, your mirror looks like it's coming along well and will be the best of the three tries. Some rotten luck on those other two, but it will turn out better anyway.
Brad
--------------------
Tom L. made 12.5" f6, "Endurance"
C80ED fixed up
Edmund 60mm f/6
Jason 60mm f/15
|
rwiederrich
Goldfinger
Reged: 11/17/05
Posts: 8683
Loc: Bremerton Washington
|
|
Quote:
Rob did give me a tour of his great shop. I saw first hand how mirrors are made and tested. It cleared up a lot of questions I had about the subject. Rob was being nice and discreet about just who messed up my focuser, it was I who filed the flat in an effort to increase friction between the roller and focuser tube. It actually did help in that regard, but as Rob mentioned it was not very flat so it bound up and had uneven motion. Now that Rob has machined it flat it looks and works very much better. Thanks Rob for the tour and work, I appreciate it.
Droid, your mirror looks like it's coming along well and will be the best of the three tries. Some rotten luck on those other two, but it will turn out better anyway.
Brad
Brad..thanks for your kind words and descriptions.
Far to often mirror making can be very intimidating to those who have neer done it. But once realized..you can see that it is simply following well documented and tested techniques and practices.
*Third times a charm* might be a good moto...for the first time...but I hope such mishaps can be completely resolved..and no such *process* need occure any longer...
I can recut that blank that got beat up to a 10".....the first one Andy sent is only good for looking at and for practice work.
Again...thanks for stopping by and dropping off those wonderful aluminum channels.....
Droid's mirror is polishing out as I expected and progress is within acceptible limits currently.
Going out there right now to fire things up..it got down to 30* last night....brrrrrrr.
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: 4258
Loc: ohio
|
|
Rob; hey this may be the lst update for a couple of days depending on when thy get CN back up and running......I sent you a pm with my personal email addy in case you need to contact me.
I doubt anything will happen, but hey you never know with my luck
--------------------
12 inch Truss Reflector "John"
102mm Celestron C102HD " Carl "
Tasco 7TE5 60mm Classic
Tasco 9TE5 60mm Classic
Celestron Ultima 2000 SCT "Wilma"
Celestron Comet catcher(orange tube)
1960 Edscorp Space Conquerer 6inch f/8
10x50 Bushnell Binoculars.
60mm Telescope Club
|
rwiederrich
Goldfinger
Reged: 11/17/05
Posts: 8683
Loc: Bremerton Washington
|
|
Quote:
Rob; hey this may be the lst update for a couple of days depending on when thy get CN back up and running......I sent you a pm with my personal email addy in case you need to contact me.
I doubt anything will happen, but hey you never know with my luck
I emailed you...but it was returned....fatal error or something with your address....
What's wrong with CN?
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: 4258
Loc: ohio
|
|
ok resent it, CN will off line for at least 24 hours so they do upgrades, or at least thats how I understand it.
Starting well thi morning , youll probably read this the day after they come back on line, lol
--------------------
12 inch Truss Reflector "John"
102mm Celestron C102HD " Carl "
Tasco 7TE5 60mm Classic
Tasco 9TE5 60mm Classic
Celestron Ultima 2000 SCT "Wilma"
Celestron Comet catcher(orange tube)
1960 Edscorp Space Conquerer 6inch f/8
10x50 Bushnell Binoculars.
60mm Telescope Club
|
droid
rocketman
Reged: 08/29/04
Posts: 4258
Loc: ohio
|
|
Were back.....yay......  
--------------------
12 inch Truss Reflector "John"
102mm Celestron C102HD " Carl "
Tasco 7TE5 60mm Classic
Tasco 9TE5 60mm Classic
Celestron Ultima 2000 SCT "Wilma"
Celestron Comet catcher(orange tube)
1960 Edscorp Space Conquerer 6inch f/8
10x50 Bushnell Binoculars.
60mm Telescope Club
|
neo
professor emeritus
Reged: 02/12/08
Posts: 724
Loc: Iasi, Romania
|
|
Finally!
I've clicked on CN address 1000 times today to see if it's back on
It's quiet addicting, you know 
--------------------
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
|
rwiederrich
Goldfinger
Reged: 11/17/05
Posts: 8683
Loc: Bremerton Washington
|
|
Finally getting to Andy's mirror again. After a great 25th anniversary celebration..getting back to work was tough and very busy. I spent some time this eveing making some mods to the table of the machine... I removed the aluminum non-adjustible cleats...and machined some nice aluminum ones that are bolted to the side of the table..but have adjust knobs that press lightly against the mirror and keep it centered on the table.
During this mod I was polishing the mirror(till I had to actually bolt them on the table).
Now we've been polishing for several hours...looking good the center in pulling out to the edges.
I also took some new shadow grams of the 8" on the stand to see the finish of the sphere. I show these images to let you see the sequence and progress of my technique that will be used on Droid's mirror. Notice the heatwaves up the center of the mirror.
--------------------
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: 8683
Loc: Bremerton Washington
|
|
That black line is a crack in the TV screan cover.....
Here is another
--------------------
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: 8683
Loc: Bremerton Washington
|
|
Looking past the tester(undernieth) and down the rail at the mirror(small center dot can be seen)...and the shadowgram to the left.
--------------------
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: 8683
Loc: Bremerton Washington
|
|
And finally a cloeup of the shadowgram...video image.
I'm using this small TV till I get my larger one in place. I upgraded the camera to a high resolution one and changed lenses and lots of mods. I'm making sure I can get the tester to its optimal state before I begin testing Droids mirror and all the other ones I'm making.
Last pic.....I'm heading outside to shut things down for the night.
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: 4258
Loc: ohio
|
|
Welcome back Rob.Comgrats on 25 years married, seems like an eternity by todays marriage standards,lol.
Didnt come home to find cats in the shop....
--------------------
12 inch Truss Reflector "John"
102mm Celestron C102HD " Carl "
Tasco 7TE5 60mm Classic
Tasco 9TE5 60mm Classic
Celestron Ultima 2000 SCT "Wilma"
Celestron Comet catcher(orange tube)
1960 Edscorp Space Conquerer 6inch f/8
10x50 Bushnell Binoculars.
60mm Telescope Club
|
rwiederrich
Goldfinger
Reged: 11/17/05
Posts: 8683
Loc: Bremerton Washington
|
|
Quote:
Welcome back Rob.Comgrats on 25 years married, seems like an eternity by todays marriage standards,lol.
Didnt come home to find cats in the shop....
Thanks Andy......no kitties....
Polished your mirror much of the day and the center is coming in(out).
I decided to make a subdi tool...so I made a 75% tool from cast iron. It ran for about 1/2hr before I shut it down for the night. The center is coming along and the outer zones are completely polished out. So tomorrow will be the subdi tool for most of the day. It's looking very nice...and boy it shines.
I hope I can control the machine artifacts...so the mirror is as smooth as possible. Only the test will tell me that.
Once I get a nice polished sphere and good straight Ronchi lines.....I'm onto the figure.
It's gonna be sad to ship this mirror out....... 
Not really! I will have another 13"f/5 ready to begin grinding right behind it anyway.
And I have some folks sending my blanks in the mail to make mirrors too........So...
And I still haven't got to my 10"f/15 refractor yet...too many mods to my machines and stuff.
I completely tore down the Porter polisher today to work on the main belt and to add a belt tensioner to one of the ecenrtic tables. Then greased everything.
Then continued hogging out the new 13".
With the tester about were I want it and the polishing coming along...I'm pretty happy...and am more prepared for more folks to send me thier mirrors for grinding/polishing.
Rob(don't forget to watch the moon tomorrow morning to see the NASA impact)
--------------------
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: 4258
Loc: ohio
|
|
starting to sound like this is your day job...lol.
Need to hire some help?? lol
--------------------
12 inch Truss Reflector "John"
102mm Celestron C102HD " Carl "
Tasco 7TE5 60mm Classic
Tasco 9TE5 60mm Classic
Celestron Ultima 2000 SCT "Wilma"
Celestron Comet catcher(orange tube)
1960 Edscorp Space Conquerer 6inch f/8
10x50 Bushnell Binoculars.
60mm Telescope Club
|
rwiederrich
Goldfinger
Reged: 11/17/05
Posts: 8683
Loc: Bremerton Washington
|
|
Quote:
starting to sound like this is your day job...lol.
Need to hire some help?? lol
Actually...after setting the machine up in the morning to polish..I rarely tend to it..but maybe once every few hours.
Then after work(around 4:00)..I'm on it full bore..till about 7:30pm when my sweetheart returns from work..
All in all I let the machines work by themselves while I work here in the office with patients. Getting it done while...I'm getting it done..
I cold pressed the new subdi tool all night..so I'll go out and get things going.
See ya.
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: 8683
Loc: Bremerton Washington
|
|
Checking in on the status of the polishing of Droid's mirror...we can see the progress.
Here are some images of that progress.
First here is the new cast iron subdi tool.
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: 8683
Loc: Bremerton Washington
|
|
A bit of a closeup to demonstrate the clearity of the mirror....you can easily see the pad belieth.
--------------------
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: 8683
Loc: Bremerton Washington
|
|
Rinsed and dried off we can see the polished surface nicely and some nice reflections.
A bit more of the center needs more polishing...but that won't take long.
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: 4258
Loc: ohio
|
|
this is exciting, and yes , Im a wee bit antsi.....firstly because I cant wait to see the moon through it.And secondly Im wondering if your airhorn scared away murphy too?
Rob that looks like it could almost be usable now, I know its my imagination...lol.Good job.
--------------------
12 inch Truss Reflector "John"
102mm Celestron C102HD " Carl "
Tasco 7TE5 60mm Classic
Tasco 9TE5 60mm Classic
Celestron Ultima 2000 SCT "Wilma"
Celestron Comet catcher(orange tube)
1960 Edscorp Space Conquerer 6inch f/8
10x50 Bushnell Binoculars.
60mm Telescope Club
|
rwiederrich
Goldfinger
Reged: 11/17/05
Posts: 8683
Loc: Bremerton Washington
|
|
Finally...showing the ceiling light in the mirrors reflection. Almost there for a first test.
I'm very pleased with polishing....it simply runs without any intervention, and I check the slurry level and occasionaly re-establish the micro fasets on the tool.
I'll run it for the rest of the day and then check it again about 5:00pm.
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
|
rwiederrich
Goldfinger
Reged: 11/17/05
Posts: 8683
Loc: Bremerton Washington
|
|
Quote:
this is exciting, and yes , Im a wee bit antsi.....firstly because I cant wait to see the moon through it.And secondly Im wondering if your airhorn scared away murphy too?
Rob that looks like it could almost be usable now, I know its my imagination...lol.Good job.
Patients...my friend.
I didn't need an airhorn to keep Murphy away...just take this more seriously....
It is quite evident that one needs to be mindful of so much and not to take ANYTHING for granted. Least the glass(kitties not withstanding).
I will use this new subdi tool to figure the mirror too.
Glad you're liking it.
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: 4258
Loc: ohio
|
|
wow , on the down image you can really see the curvature, I stand corrected I think you could focus an image with it, not perhaps a good one,lol.
Liking it doesnt cover it, Im loving it.Man this mirror is awesome.
--------------------
12 inch Truss Reflector "John"
102mm Celestron C102HD " Carl "
Tasco 7TE5 60mm Classic
Tasco 9TE5 60mm Classic
Celestron Ultima 2000 SCT "Wilma"
Celestron Comet catcher(orange tube)
1960 Edscorp Space Conquerer 6inch f/8
10x50 Bushnell Binoculars.
60mm Telescope Club
|
rwiederrich
Goldfinger
Reged: 11/17/05
Posts: 8683
Loc: Bremerton Washington
|
|
Here is a similar image showing the glare from the bright sun off the 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: 4258
Loc: ohio
|
|
WO...............................W, thats awesome image, yeah ,I havent a clue what Im talking about, but Id say shes purty dern good,
your camera ok, lol
--------------------
12 inch Truss Reflector "John"
102mm Celestron C102HD " Carl "
Tasco 7TE5 60mm Classic
Tasco 9TE5 60mm Classic
Celestron Ultima 2000 SCT "Wilma"
Celestron Comet catcher(orange tube)
1960 Edscorp Space Conquerer 6inch f/8
10x50 Bushnell Binoculars.
60mm Telescope Club
|
Spoonsize
Vendor/Clothing
Reged: 08/27/04
Posts: 3334
|
|
A simple? question....
When You post an image of the shadows on the mirror in the test stand, what side is the light source on? This will, as you know, enable me to intrepret the shadows a bit easier.
Steve
Thanks much for the rouge!
|
rwiederrich
Goldfinger
Reged: 11/17/05
Posts: 8683
Loc: Bremerton Washington
|
|
Quote:
WO...............................W, thats awesome image, yeah ,I havent a clue what Im talking about, but Id say shes purty dern good,
your camera ok, lol
I'm still not satisfied with the polish in the center.....
I threw it on the tester and WOW....Unless I'm reading the shadowgram incorrectly...it looks like the inner zones and outter zones have an abrupt edge to them. It's like the mirror is almost a parabaloid all ready. I liken it to the subdi tool I ended the last session with. i finished this eveing with the full size tool and I will check again tomorrow. By eye alone the mirror looks awesome...and glazing light is very well reflected...however the Foulcault test will reveal all manner of goofy errors.
This is the image is saw.
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: 8683
Loc: Bremerton Washington
|
|
Quote:
A simple? question....
When You post an image of the shadows on the mirror in the test stand, what side is the light source on? This will, as you know, enable me to intrepret the shadows a bit easier.
Steve
Thanks much for the rouge!
That is a good question Steve...
The LED is slighty high and to the right...also my KE comes in from both the right and the left if I wish. However...it was from the right in those images.
Glad I got you...I quickly through the 13" on the tester and saw the image I just posted of both inner and outter zones acculted. Now I didn't get to do further analysis or evaluation but from this image what can be said of this mirror from the onset? If such is even possible.
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: 4258
Loc: ohio
|
|
Rob: what is that picture??? and what does it tell you??
--------------------
12 inch Truss Reflector "John"
102mm Celestron C102HD " Carl "
Tasco 7TE5 60mm Classic
Tasco 9TE5 60mm Classic
Celestron Ultima 2000 SCT "Wilma"
Celestron Comet catcher(orange tube)
1960 Edscorp Space Conquerer 6inch f/8
10x50 Bushnell Binoculars.
60mm Telescope Club
|
Spoonsize
Vendor/Clothing
Reged: 08/27/04
Posts: 3334
|
|
Rob, post a picture, you're drawing looks pretty good, I'd like to see how abruptly the shadow changes.
|
timo4352
super member
Reged: 04/16/07
Posts: 195
Loc: Northeast Ohio
|
|
Quote:
Rinsed and dried off we can see the polished surface nicely and some nice reflections.
That's looking really nice!
I've been following along Andy, and I'm excited for you! After all that's happened, and now getting this close, you must be about ready to bust... 
Maybe if were close enough I'll get a look through this legandary mirror someday...
I just found your OAA Yahoo group and requested to join.
Tim
--------------------
Orion 3.6CA Reflector
and 2 homebrew scopes --
8" Hubble Bubble ballscope
8" F/8 CHief - nearing completion
|
droid
rocketman
Reged: 08/29/04
Posts: 4258
Loc: ohio
|
|
ok, added you to the Ohio group.Had actually given up on the group lol.
But Ill work on it agin.
--------------------
12 inch Truss Reflector "John"
102mm Celestron C102HD " Carl "
Tasco 7TE5 60mm Classic
Tasco 9TE5 60mm Classic
Celestron Ultima 2000 SCT "Wilma"
Celestron Comet catcher(orange tube)
1960 Edscorp Space Conquerer 6inch f/8
10x50 Bushnell Binoculars.
60mm Telescope Club
|
rwiederrich
Goldfinger
Reged: 11/17/05
Posts: 8683
Loc: Bremerton Washington
|
|
Quote:
Rob: what is that picture??? and what does it tell you??
This tells me the mirror isn't a sphere but possibly a parabaloid. My KE test initially revealed stark differences between the inner zones and outter zones.
When My KE acculted the light returning from the mirror it cut in half the outer zone..leaving it split in half(white on one side and black on the other)...and also split the inner zone in similar fasion. Of course because the two zones have different Centers of curvature they would not darken the same. The inner zone being aculted farther away from its center of curvature reversed the shadow..so its darkened from the opposite direction.
In short..this tells me that the mirror has 2 distinct major zones. Not unlike a parabaloid...however further testing will reveal the nature of the zones...and what correction will need to be applied.
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: 4258
Loc: ohio
|
|
Holy smokes, Im glad you understand what you just typed.....
All I know is its purty.
--------------------
12 inch Truss Reflector "John"
102mm Celestron C102HD " Carl "
Tasco 7TE5 60mm Classic
Tasco 9TE5 60mm Classic
Celestron Ultima 2000 SCT "Wilma"
Celestron Comet catcher(orange tube)
1960 Edscorp Space Conquerer 6inch f/8
10x50 Bushnell Binoculars.
60mm Telescope Club
|
Spoonsize
Vendor/Clothing
Reged: 08/27/04
Posts: 3334
|
|
Yup, I'd do zonal testing immediately. Of course, if I had a set up like yours, I'd share the pics, as well as the "numbers". 
|
droid
rocketman
Reged: 08/29/04
Posts: 4258
Loc: ohio
|
|
Steve ; do you know what he just just typed...lol.
It sounds vaguely like bad news,lol.
--------------------
12 inch Truss Reflector "John"
102mm Celestron C102HD " Carl "
Tasco 7TE5 60mm Classic
Tasco 9TE5 60mm Classic
Celestron Ultima 2000 SCT "Wilma"
Celestron Comet catcher(orange tube)
1960 Edscorp Space Conquerer 6inch f/8
10x50 Bushnell Binoculars.
60mm Telescope Club
|
greenglass
professor emeritus
Reged: 01/22/06
Posts: 557
Loc: Ontario, Canada
|
|
It's a bifocal
--------------------
10" f/5 reflector
7x50 tasco binos
60/800 tasco luminova
|
Spoonsize
Vendor/Clothing
Reged: 08/27/04
Posts: 3334
|
|
Andy:
I've been following this thread carefully. I have an inkling about what he is doing and why, but have learned much from the "master" and look forward to seeing more!
|
droid
rocketman
Reged: 08/29/04
Posts: 4258
Loc: ohio
|
|
Quote:
It's a bifocal
cooool like my glasses.
--------------------
12 inch Truss Reflector "John"
102mm Celestron C102HD " Carl "
Tasco 7TE5 60mm Classic
Tasco 9TE5 60mm Classic
Celestron Ultima 2000 SCT "Wilma"
Celestron Comet catcher(orange tube)
1960 Edscorp Space Conquerer 6inch f/8
10x50 Bushnell Binoculars.
60mm Telescope Club
|
rwiederrich
Goldfinger
Reged: 11/17/05
Posts: 8683
Loc: Bremerton Washington
|
|
I have some video monitor images..I'll post a bit later..but here are some camera images.
This first one shows the first surface condition image.
If you look hard you can see the demarcation line between the inner and outer zones..The inner zones have a rougher surface.
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: 8683
Loc: Bremerton Washington
|
|
This image shows the inner and outer zones. Note the inner zone is near null.
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: 8683
Loc: Bremerton Washington
|
|
this image shows both zones seported by thier different center of curves...that is why the KE shodow is seen on both zones..but only opposite.
This is the original image I drew.
Now I need to finish polishing out the center and blend the two extreme zones together..creating a proper figure.
Fun stuff...
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: 8683
Loc: Bremerton Washington
|
|
Another showing shadows falling across central zone dip.
--------------------
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: 8683
Loc: Bremerton Washington
|
|
One last one showing the shadow fall on the outer zon left edge and inner zone right edge.
Hope you enjoyed the fun.
Now I have to correct all the issues......stuff we're supose to do...
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: 8683
Loc: Bremerton Washington
|
|
Quote:
Andy:
I've been following this thread carefully. I have an inkling about what he is doing and why, but have learned much from the "master" and look forward to seeing more!
I jumped back up the thread and read this post....*Master*.... I am so far from a master it is funny. Those boys are awesome..and can look at a mirror and tell you right off what you need to do. I have to study things a bit longer...and I gleen from thosse experts all the time..when I can.
I do know what the figure of this mirror is supose to look like...so I need to turn what is seen..into what is suposed to be seen.. 
I do appreciate the kudos though and am always encouraged by the posting here.
Every bit helps....
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: 8683
Loc: Bremerton Washington
|
|
Previous
Index
Next
Threaded
Edit
Reply
Quote
[Re: