Norvin
Carpal Tunnel
Reged: 10/10/03
Posts: 1540
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On and off for the last several months, I have been trying to think how I could turn a standard Dobsonian mount in something like a GEM. I think I have a good idea how to do it.
I need a good software program to draw perfect lines with, copy & paste, reverse lines, has different colors, etc. I also need a small electric motor than can run off a 12 volt battery pack or power source and has plenty of torque to move a lot of weight easily (~75 lbs.). It also must have adjustable speed.
If my idea works, I think I could supply a new mount for a 12" Dob for ~$200 (maybe less) that tracks as well as a GEM and better than a tracking platform. RA would work, but I haven't figured out Dec. yet. As long as it is polar-aligned, RA should be enough.
Now don't get excited yet. This is only a very rough idea currently. But if my idea can work, a lot of people could get an Orion® SkyQuest™ XT12 Classic Dobsonian (or similar) for $859 currently and have a new wooden mount that tracks for an additional $200.
I think I can make it work for Dobsonian telescopes as small as 6".
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 Norvin
10" Black X Class (GSO) Dobsonian
Norvinian Dobsonian Telescope Mount
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snorkler
Aperture Aficionado
Reged: 10/11/04
Posts: 8722
Loc: Bay Area, California
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I, for one, would stand in line with money in hand for a $200 EQ platform for my XT10i. I'd love to have tracking, although it would drive my Intelliscope computerized object locator crazy.
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The greatest danger in the dark is your weak heart. Have you done 30 minutes of cardiovascular exercise today or yesterday?
Avg over 9000 miles
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Norvin
Carpal Tunnel
Reged: 10/10/03
Posts: 1540
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I hate it when I have these ideas floating around in my stupid head, lol.
If the idea works, I hope John Dobson likes it. It is the same idea. Providing Astronomy to everyone.
The next logical step would be to draw the design out then choose materials and then build a prototype.
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Norvin
10" Black X Class (GSO) Dobsonian
Norvinian Dobsonian Telescope Mount
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snorkler
Aperture Aficionado
Reged: 10/11/04
Posts: 8722
Loc: Bay Area, California
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Sign me up for #2, autographed by the maker, of course. It'll be a collector's item. Be sure to make it out of hardwood, as the gears will eat through soft wood.
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The greatest danger in the dark is your weak heart. Have you done 30 minutes of cardiovascular exercise today or yesterday?
Avg over 9000 miles
Avg over 3000 miles
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Norvin
Carpal Tunnel
Reged: 10/10/03
Posts: 1540
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That is a concern. It has been years since I made anything out of wood. I took carpentry classes back in high school so hopefully it is like riding a bike (you never forget). Anyway, I need to find a hardwood that is extremely affordable, lite in weight, easy to get, and extremely durable.
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Norvin
10" Black X Class (GSO) Dobsonian
Norvinian Dobsonian Telescope Mount
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Norvin
Carpal Tunnel
Reged: 10/10/03
Posts: 1540
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Over the next few days, I am going to build a small model of the mount out of cardboard. There are 2 or 3 problems I have to iron out.
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Norvin
10" Black X Class (GSO) Dobsonian
Norvinian Dobsonian Telescope Mount
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miniventures
Something Else
Reged: 09/13/03
Posts: 11197
Loc: Powell Butte, Central Oregon
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Good luck, Norvin, hope you work it out -- it would be a fine addition to the astro world.
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LarryC
Volunteer
http://www.sunrivernaturecenter.org
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spaceydee
Postmaster
Reged: 04/16/04
Posts: 15893
Loc: Where the Kittens Are
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I look forward to seeing your model!
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Dee
space-scientist
student violinist
Nexstar8i,SV80S,80/9D,FC100,94 Brandon,TMB92SS,GM8
8" f/7 Discovery,12.5" Portaball, PST
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Kieken
sage
Reged: 10/03/04
Posts: 235
Loc: Kapellen, Belgium
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This sounds very nice, I hope you can work it out (and eventually produce those things).
One point: make the tracking as good as possible so that us dob users can join the world of astrophotography without high costs and stuff  .
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WO Megrez 110 ED on Vixen Sphinx
Celestron 12" Starhopper
Celestron 80/900 Powerseeker
4.5" Newton on regreased EQ-2
D40x / Nikkor AF-S 18-55 / Nikkor AF-S 55-200 / Tamron AF 28-200mm Super II Macro
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ForgottenMObject
Post Laureate
Reged: 09/11/04
Posts: 3589
Loc: Maryland, US
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Hmmmm... would TurboCAD work for the CAD program? (Not sure if they even still sell that - it was a cheaper cousin of AutoCAD.)
Sounds like a great idea!
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Matthew
IDA member
XT8i, 10x50 binoculars, lots of eyepieces
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Norvin
Carpal Tunnel
Reged: 10/10/03
Posts: 1540
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Well the basic cardboard model I made seems to work. So now I will buy some wood and build a prototype over the next few weeks as I am sure I will have to move things around, recut wood, run into problems, etc.
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Norvin
10" Black X Class (GSO) Dobsonian
Norvinian Dobsonian Telescope Mount
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Norvin
Carpal Tunnel
Reged: 10/10/03
Posts: 1540
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I guess I could make the prototype out of pine. I might start work on it this weekend and maybe get it done during the same weekend or the next one.
The design is so simple that it is funny. I have yet to see anything like it and I have looked extensively on the web to be sure.
I looked at tracking platforms for Dobs. The prices being asked are outrageous from something that will only track accurately for an hour. Maybe two.
I want my mount to be able to track for a maximum of 3 hours. The more the better, but 3 hours is the goal.
The prototype will not have a motor. I am not good with electric motors. As I said in a previous post above, I need one that has plenty of torque, adjustable speed with extremely slow speed to allow tracking but also fast enough to move the mount back to a different location somewhat quickly. I also need this motor to be able to shut down if a certain amount of tension is met.
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Norvin
10" Black X Class (GSO) Dobsonian
Norvinian Dobsonian Telescope Mount
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Norvin
Carpal Tunnel
Reged: 10/10/03
Posts: 1540
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I have now made detailed drawings of the mount. At this point, I don't think the mount will be able to handle a 12" GSO and Synta Dobsonian OTA. It should handle 6" - 10" GSO and Synta OTAs just fine.
I will now need to go buy the wood. From a suggestion from rboe, I am going to try to use ash for the wood.
It turns out I won't have to rely on my high school wood shop skills after all, lol. A friend of my Dad owns a wood shop that my Dad's friend and his son own and operate. They should be able to cut the wood the way I need it cut cheaply.
The remaining problems are finding a motor to allow tracking and seeing if the mount will support the OTA correctly.
I have no idea what motor I could use. The requirements it would have to perform are...
- Has to have a 1 inch diameter wheel that allows a thin steel cable to be wrapped around the wheel once and not tangle or twist.
- Has to have adjustable speed to allow 1X - 10X (or faster) sidereal speed.
- Has to have plenty of torque to move the weight, but also has to have a way to automatically turn off once a certain point of motion from the mount has been reached so the motor doesn't burn itself out or ruin the mount.
- Must run from 12 volts of power and have a speed controller preferably with a dial for fine-tuning the speed.
As for the OTA, I am so confident the mount will work that I am going to cancel my order for the Orion SVP 8" Reflector and order a 10" Dobsonian either from Orion, Sean's, or DBA. Does anyone know of a vendor that carries Orion Classic Dobsonians that perhaps ships for free?
Lastly, instead of calling it a "Dobsonian Polar-Aligned Motorized Tracking Mount", I am now going to call it the "Norvinian Dobsonian Telescope Mount" for 2 reasons...
- 'Norvin' literally means 'Friend From The North'. Since my mount allows polar-alignment using Polaris (The North Star), Polaris becomes your new northern friend.
- Norvin is my name, lol.
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Norvin
10" Black X Class (GSO) Dobsonian
Norvinian Dobsonian Telescope Mount
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snorkler
Aperture Aficionado
Reged: 10/11/04
Posts: 8722
Loc: Bay Area, California
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The altitude motor used by Stellarcat in its ServoCat drive system sounds like it meets your specifications.
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The greatest danger in the dark is your weak heart. Have you done 30 minutes of cardiovascular exercise today or yesterday?
Avg over 9000 miles
Avg over 3000 miles
Edited by snorkler (10/11/05 12:51 AM)
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Norvin
Carpal Tunnel
Reged: 10/10/03
Posts: 1540
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Do you have a link to it and a price? Remember, the whole idea for my mount is to allow affordable tracking for Dobsonian telescopes.
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Norvin
10" Black X Class (GSO) Dobsonian
Norvinian Dobsonian Telescope Mount
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anat
sage
Reged: 06/03/04
Posts: 234
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I recommend Hurst motors. It costs about $60 each.
http://www.myhurst.com/hurstmfg/qseries.jsp?series=Series+LSG35+Geared+Stepping+Motor
You can find a motor driver from:
http://www.tomhole.com/EQ%20Platform.htm
http://www.kitsrus.com/kits.html#k109
I also developed a motor driver with an ASCOM driver.
Anat
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Astro-physics 155EDT
Borg 60ED
Losmandy G11 Gemini
Hypermodded Canon 450D
LVI SmartGuider
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Norvin
Carpal Tunnel
Reged: 10/10/03
Posts: 1540
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Thanks I'll check into that.
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Norvin
10" Black X Class (GSO) Dobsonian
Norvinian Dobsonian Telescope Mount
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netwolf
member
Reged: 09/03/05
Posts: 86
Loc: NSW, Australia
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Hi Norvin,
Hats of to you, great idea you have. Any way to make the polar alignment work for us south of the equator folk. Do you forsee shipping this item overseas for sale, either fully made or in a kit form. I have a GSO 10" dob.
Do you have any sketches you can share at present. There are some guys in the Iceinspace forums downunder who are also working on a similar solution, using a wedge under the dob base.
Regards
Netwolf
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Norvin
Carpal Tunnel
Reged: 10/10/03
Posts: 1540
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netwolf: I'll have to get back to you on that. I have to build the prototype first.
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Norvin
10" Black X Class (GSO) Dobsonian
Norvinian Dobsonian Telescope Mount
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Norvin
Carpal Tunnel
Reged: 10/10/03
Posts: 1540
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This is getting funny. I was going through the drawings I made for my mount and came up with another design that should work just as well and is somewhat simpler. So I now have 2 DESIGNS!!! Both allowing Dobsonian telescopes to be polar-aligned and to track.
This new design should easily allow 12" and quite probably bigger Dobsonians to be polar-aligned.
At any rate, tomorrow I am going to go get the wood to build both designs.
At this point, I am reluctant to discuss the designs or show pictures of either (upon building them) as I will seek a patent on both designs. Perhaps one of the CN members who is an attorney could guide me with the patent process.
netwolf: Either design should be able to work in the Southern Hemisphere.
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Norvin
10" Black X Class (GSO) Dobsonian
Norvinian Dobsonian Telescope Mount
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