Build Project: Dob Equatorial Platform

[SniffTheGlove]

Thanks Mark

[sandspider]

No, Problem. I'll be back when I start into my mount!

Mark

[sandspider]

Sean,

Was thinking about the drive for the platform. What would you thing of using a flexible rack and driving it with a pinion or worm gear? It should give very steady smooth movement from a simple system. I think the work gear would be better if it could be mounted correctly.

Mark

[SniffTheGlove]

Sean,

Was thinking about the drive for the platform. What would you thing of using a flexible rack and driving it with a pinion or worm gear? It should give very steady smooth movement from a simple system. I think the work gear would be better if it could be mounted correctly.

Mark

There are designs out there that use a plastic flexible rack, they use

http://www.conrad.com/Gear-rack.htm?websale7=conrad-intπ=237396&ci=SHOP_AREA_14780_1210078&Ctx={ver%2F7%2Fver}{st%2F3ec%2Fst}{cmd%2F0%2Fcmd}{m%2Fwebsale%2Fm}{s%2Fconrad-int%2Fs}{l%2Fint%2Fl}{sf%2F%3Cs1%3Erack%3C%2Fs1%3E%2Fsf}{p1%2F3862400e806a738709b186abca7d749e%2Fp1}{md5%2F92210bb1e91091f4eb782cc1764a0514%2Fmd5}

and then use associated gearing etc from the same company.

It would do the trick as long as the motor you choose has enough torque to shift the platform and your scope and also be controllable to alter for different speeds for sky or moon tracking. Best bet is a motorgearbox as stepper motors don't offer the same torque levels but then you will need a speed controller instead of an Arduino. I leanrt the hard way but was able to use the stepper motors and Arduino for my motorised focuser.

[sandspider]

Yes, I think this could be a good plan. I'll do some more research and let you know how I get on.

[Douglas]

Hi guys I've had a read of this thread and wonder how you are getting on with the projects. I too am planning to build a platform but I want to use the design where the north segments stay verticle which requires not using a circular cut but to instead use some trig equation (something like cos alpha alpha being the lattitude) to make more of an oval, however the math has me going crazy and I need some sort of program to draw the final result.

Any help would be great

[SniffTheGlove]

All my trig was done on my speadsheet and then verified on paper with my old technical drawing setup. The speadsheet is in my last post on page one of this thread. Not sure if it fits your plans but have a look at it, just fill in the green boxes in the cells with your data and it does the rest and the main stuff to note is the answers in the yellow cells.

[SniffTheGlove]

SGL User Stan has updated my Spreadsheet to add a complete list of Long/Lat coords for all US cities to help make the location setting easier.

Sean_Astro.xls