mitaccio
super member
Reged: 03/17/09
Posts: 147
Loc: Tooele, Utah
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Either I'm a poor internet searcher, or it's actually hard to find instructions on making an equatorial platform. I want to make one for my 10" lightbridge and don't think $700+ for one is a fair price.
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LightBridge 10"
Messier Checklist 47/110
Edited by mitaccio (06/30/09 06:23 PM)
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Jason D
Post Laureate
Reged: 10/21/06
Posts: 3750
Loc: California
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Join the Eq platform yahoo group. There are plenty of plans and expertise over there
http://tech.dir.groups.yahoo.com/group/eqplatforms/
Jason
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XT10 classic with premium optics
Tri-knob CR2 with compression rings
Round Table Platform
4.5" StarBlast
6" StarBlast6
TV EPs
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wirenut
professor emeritus
Reged: 09/21/06
Posts: 603
Loc: m'dale Pa
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if you google Warren Peters equatoral platform you'll find plans and explaination and a account of his build. I dont know if that will give you the excel spreadsheet to figure out deminsions. the yahoo group I'm sure has that on file or if not go to stellafanes website look in thier ATM links page they have aseveral plans and spreadsheet too.
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8"GSO dob
EQ platform
8,17 mm hyperions & FT rings
21mm stratus
25,15,9 mm plossls
ultima barlow
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14dobguy
scholastic sledgehammer
Reged: 12/09/08
Posts: 819
Loc: rhode island
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nice thread mittacio...i am also in the market for an equatoral table,and $700 for one is just way too much for my pockets.
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Brian
14" dob
sky commander
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14dobguy
scholastic sledgehammer
Reged: 12/09/08
Posts: 819
Loc: rhode island
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has anyone on here (cloudy nights) built an equatoral table? and if yes,can you give an idea of the complexity,or a 1-10 how hard it is.i just joined the yahoo group,and it looks a bit intimidating...although i AM up to the challenge lol.
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Brian
14" dob
sky commander
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Lenardo
sage
Reged: 02/19/09
Posts: 233
Loc: Ma
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i've looked into it, the Hardest part imo is the motor, the rest is fairly straight forward wood working.
one round cut, per rail
one straight angle cut per rail
i'd say, woodworking ~5
electronic controls ~7.5
and assembly
i priced out all but the electronics @ 100 dollars, add ~40 for electronics.
Edited by Lenardo (06/30/09 09:10 PM)
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14dobguy
scholastic sledgehammer
Reged: 12/09/08
Posts: 819
Loc: rhode island
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thanks lenardo...i figure e-bay for the stepper motors...e-bay for everything haha.baltic birch at the depot is $55 i am in no way trying to hijack your thread mitaccio...but i am also very interested in building one.
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Brian
14" dob
sky commander
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Gene Baraff
sage, 1930-2010, Rest In Peace
Reged: 03/22/09
Posts: 265
Loc: Berkeley Heights, N.J.
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In re: the Yahoo Equatorial Platforms Group:
After you choose the type of E.P. you want (Cylindrical runners, like Chuck Shaw or Warren Peters - or Vertical North Sector VNS - like Tom Opatowski builds and sells) you'll find plans and spread sheets for the dimensions in the the Files Section of that group. You'll also find the Sacred Texts (the original papers by Shaw, Peters, Shouldice and d'Autumne) there. Then, you'll find spreadsheets for working out the torque and speed requirements. But best of all, you'll find a fantastically friendly and experienced coterie of forum members who will be more than glad to answer any concern or question you might have.
Gene Baraff
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Lenardo
sage
Reged: 02/19/09
Posts: 233
Loc: Ma
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personally -i am going the shaw/peters route whenever i get around too it.
i've joined the yahoo group and am doing the design in autocad whenever i am bored at work.
Edited by Lenardo (06/30/09 11:34 PM)
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wojo
sage
Reged: 09/28/07
Posts: 218
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Hello
I too was a little doubtfull about the electronics for the motor. So I decided to use a gear head motor and just speed up or slow it down with a pot ( potentiometer) the people I contacted recommended a steeper motor with a controller but said a pot would also work.
So I did and it works fine. A small gear head motor from American scientific. and a pot from radio shack. The motor should be about 5-7rpm. and the pot helps slow it down or up . Getting the angles right is important , and there final positioning on the ground board right. but it's only a matter of trial and error.
The only thing I did not care for is the setup time. It has to be perfect or the object of desire slowly drifts out of the center. So setting up every time is a pain, at least for me. Would work great, if you didn't have to move scope in and out (observatory)
Total cost was about 75.00 And could have been cheaper if I scrounged more Parts instead of buying them.
Good info on Stellefanes site. Pm'd Jan Van GASTEL and he was VERY helpfull. HOPE this helps................WOJO
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Vincent Becker
sage
Reged: 09/16/08
Posts: 209
Loc: France
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Here are some pages about the EQ platform made by my father:
http://www.telescope-amateur.net/?/200_La-table-equatoriale/Construction-de-la-table-equatoriale
And the 2-axes motorization (alt motor added by myself):
http://www.telescope-amateur.net/?/200_La-table-equatoriale/La-motorisation
And even a polar finder:
http://www.telescope-amateur.net/?/200_La-table-equatoriale/Le-viseur-polaire
It is in French but has a lot of pictures. You can navigate in each section with the numbered list on top and bottom of each page. Feel freee to ask any questions!
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Vincent Becker
10" dobsonian on EQ platform (home-made by my father)
8" string newtonian as travelscope (home-made by myself  )
Orion 80ED and GSO 200/1000 on Atlas EQ-G for astro-imaging
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reiner
super member
Reged: 09/28/05
Posts: 118
Loc: Freiburg, Germany
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I have detailed instructions on how to design and plan a sturdy low profile equatorial platform, either with circle segment or vertical north segment. You can find it
here under "eq platform"
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Reiner
22" and 14" Dobs on EQ platforms and Deep Sky Observing
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Ed Jones
Pooh-Bah
Reged: 04/06/04
Posts: 1476
Loc: Sin-sin-atti
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They don't any simpler or cheaper than this.
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Ed Jones
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mitaccio
super member
Reged: 03/17/09
Posts: 147
Loc: Tooele, Utah
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Quote:
Here are some pages about the EQ platform made by my father:
http://www.telescope-amateur.net/?/200_La-table-equatoriale/Construction-de-la-table-equatoriale
And the 2-axes motorization (alt motor added by myself):
http://www.telescope-amateur.net/?/200_La-table-equatoriale/La-motorisation
And even a polar finder:
http://www.telescope-amateur.net/?/200_La-table-equatoriale/Le-viseur-polaire
It is in French but has a lot of pictures. You can navigate in each section with the numbered list on top and bottom of each page. Feel freee to ask any questions!
Lucky I speak french well enough to follow. Looks like your dad makes a good EQ platform.
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LightBridge 10"
Messier Checklist 47/110
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Vincent Becker
sage
Reged: 09/16/08
Posts: 209
Loc: France
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Thank you! It is very efficient. The only drawback is that it is quite high due to the south axis and the 45° motorization. A platform with two sectors, with a vertical one to the north, is more compact;
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Vincent Becker
10" dobsonian on EQ platform (home-made by my father)
8" string newtonian as travelscope (home-made by myself )
Orion 80ED and GSO 200/1000 on Atlas EQ-G for astro-imaging
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kcbridgeman
member
Reged: 03/26/09
Posts: 92
Loc: Kansas City, MO
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I have built one for a fellow astronomer using Warren Peters design. I had to create the excel program he uses that I can e-mail to anyone who wants it. It's pretty straight forward. I also have the .pdf that explains his design. Just pm me.
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Orion XT10/Telrad/Stellarvue F50M RACI
Numerous Eyepieces
Starry Night Pro Plus 6/Pocket PC w/Pocket Stars
Who are we? What are we? We find that we inhabit an insignificant planet of a hum-drum star lost in a galaxy tucked away in some forgotten corner of a universe in which there are far more galaxies than people. ~ Carl Sagan
Edited by kcbridgeman (07/06/09 09:46 PM)
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arpruss
scholastic sledgehammer
Reged: 05/23/08
Posts: 952
Loc: Waco, TX
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Quote:
Either I'm a poor internet searcher, or it's actually hard to find instructions on making an equatorial platform. I want to make one for my 10" lightbridge and don't think $700+ for one is a fair price.
Well, one can find them for about $300, so $700 is an overestimate. E.g.:
http://home.netcom.com/~tlsystem/
http://supernorthstars.tripod.com/id1.html
Of course, maybe these ones are junk.
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Coulter Odyssey 13.1" split-tube
Coulter Odyssey 8"
Home-made 7.8" F/4 dobsonian travel scope
Home-made 68mm F/5.3 achro (typically used as finder on 13.1")
Skymaster 15x70
BPTs4 8x30
32mm Plossl, 30mm GSO SV, 30mm Rini, 27mm Kellner, 13mm Hyperion, 6mm TMB/BO Planetary, Owl 2X Barlow
Palm TX with AstroInfo and RescoViewer
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Jim Romanski
Pooh-Bah
Reged: 01/02/05
Posts: 1017
Loc: Guilford, Connecticut
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The links section on the Stellafane website is always a good place to start looking for ATM info:
Take a look at some of their equatorial platform links:
http://stellafane.org/misc/links.html#Platforms
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Jim
17.5" Dob "Project"
13.1" Coulter
8” Cave
NP 101 on a CG-5
25x100 binos
Naglers, Ethos, etc.
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Steven Aggas
sage
Reged: 04/15/08
Posts: 474
Loc: Arizona
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Quote:
They don't any simpler or cheaper than this.
They might not, but you'll notice the polar bearing will not pass through the center of gravity of the platform/scope combo, therefore this construction will be very top-heavy and could tip over quite easily when at the beginning or ending of the travel, or, in other words, the amount of travel is very limited on either side of a flat platform before the scope becomes tippy.
I built the D'Autumn version for my 20" in 1995. Not much internet back then, so I designed my platform based upon the pictures in Mr. D'Autumn article that ran in S&T. I'll give him credit since only the drive mechanism was different.
My platform was balanced in 3D and used for ccd imaging with good results.
Things to avoid, or, consider: 1. Flexure caused by the use of flimsy materials in the platform can make observing frustrating, as much as flimsy materials used in the scope mount can be. 2. Getting the CG of the scope/platform determined and on-axis with the virtual pole close is all that's needed, within +/- 1 inch should be good. 3. Friction drive system. Since the platform will want to pivot East-West as the platform rolls around its pole, the telescope when pointing East or West and then raised or lowered in altitude could overpower the friction drive of the platform if the altitude bearing friction is too high, or at least higher than the amount need to get the platform to skip over its friction drive.
Steven
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Mr. Wizard
Walking on a Dob: http://darkskyobserving.com/MtGraham.html
Elements in Harmony I, an 8"f6 German Equatorial - Stellafane Winner,
II a 20"f4.2 Newt-Dob - Astrofest Winner,
III a 6"f3.5 Finder/Newt-Dob, and
IV a 36"f4.5 Newt-Dob - "If it's up there, it's in here."
Apache-Sitgreaves Center for Astrophysics
www.DarkSkyObserving.com
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Ed Jones
Pooh-Bah
Reged: 04/06/04
Posts: 1476
Loc: Sin-sin-atti
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No my platform is not top heavy or tipsy at all! Even when I use it with scopes it wasn't designed for and it tracks just fine with no slippage because it has 2 drive motors. Comparing performance, cost and aesthetics I'd say you're not even close.
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Ed Jones
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