dawsonian2000
Pooh-Bah
Reged: 07/26/06
Posts: 1434
Loc: Riverview, FL, USA
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Hey Netwolf,
Believe me, it took a long time to come up with the idea for this fork mount. You can do it too with time, patience, and tools.
BTW - Thanks so much for the links! I already know about Optic Craft Machining, but the other one really seems to have some good prices on parts, etc.
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Clear Skies, Forever!
The Vega Sky Center
10" (254mm) F/5.65 Homebuilt Fork Mounted Newtonian Reflector
5" (127mm) F/9.4 Homebuilt Refractor
4" (100mm) F/13 Carton Homebuilt Refractor
3.1" (80mm) F/6 Scopos ED APO Refractor
4.5" (114mm) F/8 Tasco 11te-5 Newtonian (under restoration)
2.4" (60mm) F/16.7 Tasco 7te-5 Refractor
2.4" (60mm) F/15 Jason Discoverer 313 Refractor
http://www.vega-sky-center.com
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eric moerman
super member
Reged: 11/08/03
Posts: 279
Loc: belgium
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Today some more milling done.
Pictures is of the coupling between Dec.axis and the cradle.
eric
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eric moerman
super member
Reged: 11/08/03
Posts: 279
Loc: belgium
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axis and cradle disassembled.
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dawsonian2000
Pooh-Bah
Reged: 07/26/06
Posts: 1434
Loc: Riverview, FL, USA
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I like the system you have here. I think Art may be leaning toward the same type of design for his DEC axis now that I understand it better. I wish I would have done something like this myself. Thanks to you, and Art Bianconi, the knowledge I am gaining here will help me tremendously with my next project. Thanks to you both. 
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Clear Skies, Forever!
The Vega Sky Center
10" (254mm) F/5.65 Homebuilt Fork Mounted Newtonian Reflector
5" (127mm) F/9.4 Homebuilt Refractor
4" (100mm) F/13 Carton Homebuilt Refractor
3.1" (80mm) F/6 Scopos ED APO Refractor
4.5" (114mm) F/8 Tasco 11te-5 Newtonian (under restoration)
2.4" (60mm) F/16.7 Tasco 7te-5 Refractor
2.4" (60mm) F/15 Jason Discoverer 313 Refractor
http://www.vega-sky-center.com
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eric moerman
super member
Reged: 11/08/03
Posts: 279
Loc: belgium
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Today i geth the pieces back from lasercutting. 
They will be used for the forkarms and the base of the mount.
eric
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Art Bianconi
Post Laureate
Reged: 03/06/06
Posts: 4659
Loc: Delaware River Valley, New Jer...
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Mel, thanks for the acknowledgment. The truth be told, 99% of what I know, I learned from others.
It's not possible to "pay back" such generosity so I am "paying forward" (Robert Heinlein), instead.
Art
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“Everything is on its way to somewhere. . . . . everything!"
____________________ George Malley (John Travolta)
________________________ "Phenomenon"
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dawsonian2000
Pooh-Bah
Reged: 07/26/06
Posts: 1434
Loc: Riverview, FL, USA
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Same here... in the form of my website to show others what I have learned from others and through innovation. I continue to learn from amateurs like yourself and others for future projects to develop new ideas. My associate Gary Barabino is also an awesome resource in my continuous growth. The pleasure is indeed all mine... 
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Clear Skies, Forever!
The Vega Sky Center
10" (254mm) F/5.65 Homebuilt Fork Mounted Newtonian Reflector
5" (127mm) F/9.4 Homebuilt Refractor
4" (100mm) F/13 Carton Homebuilt Refractor
3.1" (80mm) F/6 Scopos ED APO Refractor
4.5" (114mm) F/8 Tasco 11te-5 Newtonian (under restoration)
2.4" (60mm) F/16.7 Tasco 7te-5 Refractor
2.4" (60mm) F/15 Jason Discoverer 313 Refractor
http://www.vega-sky-center.com
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dawsonian2000
Pooh-Bah
Reged: 07/26/06
Posts: 1434
Loc: Riverview, FL, USA
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Great looking components for your fork head! How will they be joined together? Will they be welded?
--------------------
Clear Skies, Forever!
The Vega Sky Center
10" (254mm) F/5.65 Homebuilt Fork Mounted Newtonian Reflector
5" (127mm) F/9.4 Homebuilt Refractor
4" (100mm) F/13 Carton Homebuilt Refractor
3.1" (80mm) F/6 Scopos ED APO Refractor
4.5" (114mm) F/8 Tasco 11te-5 Newtonian (under restoration)
2.4" (60mm) F/16.7 Tasco 7te-5 Refractor
2.4" (60mm) F/15 Jason Discoverer 313 Refractor
http://www.vega-sky-center.com
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eric moerman
super member
Reged: 11/08/03
Posts: 279
Loc: belgium
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Mel,
the components of the fork head and arms will be screwed and glued togheter.
Today i could work some more (10 hours :smirk )on the mount.
Most of the milling is done,only some smal parts,so now i can start assembel al the things.
Here are some pictures of the base plate and polar disk bolted togheter.
You can also see the pieces on top of the polar disc that will be used to disassembel the fork arms from the disc for transport
2 pictures is of the fork arms whit the dec house togheter.
eric  (for my wife who lets me go to work on telescope al day long  )
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eric moerman
super member
Reged: 11/08/03
Posts: 279
Loc: belgium
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2 picture whit 1 of the plates disconnected
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eric moerman
super member
Reged: 11/08/03
Posts: 279
Loc: belgium
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mount and 1 of the forks.
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dawsonian2000
Pooh-Bah
Reged: 07/26/06
Posts: 1434
Loc: Riverview, FL, USA
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Eric,
All I can say is... WOW, what a fork mount!!! I love the low-yield design and the meticulous care you put in the fork arms. But, I am curious - what type of glue you will be using since your mount is metal?
Thanks for keeping us all updated with the progress of you telescope. It will go a long way in instilling new techniques in the design and construction of home-built fork based telescopes to all interested amateurs.
--------------------
Clear Skies, Forever!
The Vega Sky Center
10" (254mm) F/5.65 Homebuilt Fork Mounted Newtonian Reflector
5" (127mm) F/9.4 Homebuilt Refractor
4" (100mm) F/13 Carton Homebuilt Refractor
3.1" (80mm) F/6 Scopos ED APO Refractor
4.5" (114mm) F/8 Tasco 11te-5 Newtonian (under restoration)
2.4" (60mm) F/16.7 Tasco 7te-5 Refractor
2.4" (60mm) F/15 Jason Discoverer 313 Refractor
http://www.vega-sky-center.com
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eric moerman
super member
Reged: 11/08/03
Posts: 279
Loc: belgium
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Mel,
yes,i tried to keep the whole thing as low as possibel to the ground.
When i look to the east or west the fork arm will be clearing the ground whit around 5 cm (2 inch).
Thats 1 of the bad things in the desing of the lightspeed in my opinion that its pretty high of the ground so i try'd to change that.
My tube is 2.60m (around 102")long so the lower it is the smaller the ladder i can use.
There is glue that is specificly made to glue metals .
If you want i will look whats the name of it at my work place.
When the arms are completly assembeld i will also fill the up as much as possibel whit PU foam,that will also keep the whole thing togheter more and dampen any vibration.
eric
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dawsonian2000
Pooh-Bah
Reged: 07/26/06
Posts: 1434
Loc: Riverview, FL, USA
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Eric,
When I built my fork mount, I also wanted to make it as low as possible for observing, but at the same time I had to be sure the mount did not hit anything as it is swung into various positions.
I like your idea to add PU foam inside the fork arms for dampening, especially since metal has a tendancy to transmit vibrations due of its molecular structure. The foam will undoubtably eliminate this problem.
Thank you for offering to provide me with the name of the metal adhesive you will be using. I look forward to receiving the name of it! 
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Clear Skies, Forever!
The Vega Sky Center
10" (254mm) F/5.65 Homebuilt Fork Mounted Newtonian Reflector
5" (127mm) F/9.4 Homebuilt Refractor
4" (100mm) F/13 Carton Homebuilt Refractor
3.1" (80mm) F/6 Scopos ED APO Refractor
4.5" (114mm) F/8 Tasco 11te-5 Newtonian (under restoration)
2.4" (60mm) F/16.7 Tasco 7te-5 Refractor
2.4" (60mm) F/15 Jason Discoverer 313 Refractor
http://www.vega-sky-center.com
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netwolf
super member
Reged: 09/03/05
Posts: 127
Loc: NSW, Australia
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Eric,
Perhaps this is a noob question, but i cant work out how you intend to polar align? its seems you have built it for a particular Latitude?
Mel same question to you with your wodden fork how do you adjust your latitude for polar alignment?
I am in awe of both your mounts, you guys think you can make and ship one to me in Sydney Australia?
Regards
Edited by netwolf (08/07/06 09:42 AM)
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Art Bianconi
Post Laureate
Reged: 03/06/06
Posts: 4659
Loc: Delaware River Valley, New Jer...
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You are correct Mel: foam will help dampen vibrations in virtually any material but in the context of adding strength, it is even more beneficial.
I came across this statement while searching for some carbon fiber. It addresses a popular question far better than I can.
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"Why use core Materials when making composite sandwiches?
The use of core materials can be very advantageous. When core material is used to double the thickness of a structure, the relative stiffness increases 7 times. The strength increases 3.5 times while the weight only increases 1.03 times. When core material quadruples the thickness, the relative stiffness increases an incredible 37 times, the strength increases 9.2 times, but the weight only increases a mere 1.06 times."
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To be truly effective, however, the foam is best poured into the fork and allowed to expand to fill every nook and cranny.
I would calculate the internal volume of the fork in cubic centimeters and catylize just enough of "Pour-N-Place" foam to fill that void plus 5%.
You can alter the density of the expansion by constraining it in a volume less than what it is looking for. There is nothing to be gained by doing so.
Typically, I pour my catylized foam into a carboard box just a bit larger than the part I wish to make; wait a few minutes then tear the box apart.
Hand fitting foam to a precise interference tolerances is not effective in my experience.
I too am very interested in the adhesive used to bond metals.
Thanks
Art
==================================
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“Everything is on its way to somewhere. . . . . everything!"
____________________ George Malley (John Travolta)
________________________ "Phenomenon"
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eric moerman
super member
Reged: 11/08/03
Posts: 279
Loc: belgium
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Hi,
i did ofcorse also check that the mount and fork never hit anywhere,they clear the legs and the ground whit about 5 cm.
The adhesive i will use is from Loctite,buth i already forget what type it was   
Tomorow i look again and will post it here.
I remember they discreibe it as structural adhesive buth there are still around 7 different type's.
Art,i happend to work before in the oil and gas bussines for insulating gas and oil tanks(the big ones you see in the harbor).
In there they also had some foam you just puth togheter and then you had around 1 min.before it started to work.
I still have around 10 liter of it in my house now 
I think the foam is preventing the skin from buckling and by this way make the arms much stronger and siffer,like you writhe before Art.
In the same time it also dampens vibration verry good so thats 2 good points from adding only 1 more member.
If you always try to do this you geth a verry effective build scope.
Netwolf;no its no a "noob" question.
There is indeed no way to change the latitude,its build for belgium(51°).
I do not intend to travel far whit this scope,only to England ,Germany and France so they are al around the same latitude.
To polar alingn i use screws at the end of the legs for now.
Later i will make the base of the mount moveble in altitude and azimut.
If you want i can make you a mount,no problem. 
Thank you al for the compliments.
eric
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dawsonian2000
Pooh-Bah
Reged: 07/26/06
Posts: 1434
Loc: Riverview, FL, USA
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Netwolf,
My answer to the latitude adjustment is pretty much the same as Eric's. I do not intend on moving anytime soon so I basically built-in the declination of the fork to 30 degrees for New Orleans, LA (my home town) should I decide to take a trip there to see my friend and colleague Gary Barabino.
My latitude here in Riverview, FL is approximately 27 degrees. But, I have devised a means to incline the mount for higher latitudes that will utilize a large bolt and t-nut, a wind nut, and a washer. I will post the plans and photos on my website as time permits.
Also, if by chance I should move to a higher latitude locale, I could drill additional holes for the lowers bolts on both sides of the two Fork Mount Base upright supports that hold the RA Axis Support Housing and pivot the housing upwards from the bottom (See attached illustration).
If I had a choice, I would go with Eric's mount. But, I would be happy to assist you if you are looking to build one using wood. 
--------------------
Clear Skies, Forever!
The Vega Sky Center
10" (254mm) F/5.65 Homebuilt Fork Mounted Newtonian Reflector
5" (127mm) F/9.4 Homebuilt Refractor
4" (100mm) F/13 Carton Homebuilt Refractor
3.1" (80mm) F/6 Scopos ED APO Refractor
4.5" (114mm) F/8 Tasco 11te-5 Newtonian (under restoration)
2.4" (60mm) F/16.7 Tasco 7te-5 Refractor
2.4" (60mm) F/15 Jason Discoverer 313 Refractor
http://www.vega-sky-center.com
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Art Bianconi
Post Laureate
Reged: 03/06/06
Posts: 4659
Loc: Delaware River Valley, New Jer...
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The RA box on my 8" travel scope must have a lot of angular travel, not simply for the purpose of polar alignment, but to allow it to store compactly in the travel case.
Art
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“Everything is on its way to somewhere. . . . . everything!"
____________________ George Malley (John Travolta)
________________________ "Phenomenon"
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rwiederrich
Goldfinger
Reged: 11/17/05
Posts: 12501
Loc: Always Dark skies of Belfair W...
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There has been a great deal of very interesting talk, and fork mount design ideas being discussed here. I thought I would post a pic of a very nice homemade fork design/scope that belongs to the San Diego Astronomy Assoc.
It is a 16"f/5.2 Newtonian.
I think they did a great job.
Image is several years old.
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http://tech.groups.yahoo.com/group/HomemadeRefractorTelescopes/ My homemade refractor group. www.goldmtobservingcenter.com
www.vimeo.com/6014031
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