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EQ platform - large latitude change

ATM DIY
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#1 tincanandstring

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Posted 25 April 2019 - 12:41 AM

I purchased an Osypowski EQ platform on the classifieds here about 8 years ago. It worked great with my 10” f5.6 Orion PDSE until I began to have back issues and needed to sit to observe. Latitude about 33.5 N.

I have retired to a warm place at 11 degrees N. The platform had been put away and simply got shipped here. On my meager SS spending money, a new $1000+ platform is out of the question, so I gave the operation of the platform some thought. My current Dob is 8” f5, eyepiece much lower to the ground.

 

The platform has the xtal circuit and 4 button box, only RA used. What could I do to use it here, other than getting out the saw and rebuilding? If it sits flat on the ground here, the stars would revolve around a point 22.5 degrees above the NCP.

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Edited by tincanandstring, 25 April 2019 - 01:02 AM.


#2 tincanandstring

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Posted 25 April 2019 - 12:47 AM

What if I mounted the platform on a wedge, south end 22,5 degrees higher? This should put the polar axis on the NCP.

 

The double south bearings are still inclined away from the front of the platform, but the lower CG of the load might cause instability.

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#3 tincanandstring

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Posted 25 April 2019 - 01:00 AM

So if I added a wedge facing opposite on top, this should stabilize things. I need to calculate the CG location and adjust with weights or whatever, and I need a safety so a bump won’t send the moving top section downhill. I think a couple of roller blade wheels, one for each north sector, on brackets attached to the lower wedge/base assembly might work.

 

I have larger stepper motors, can change out the existing or add one for each north bearing, and I have a number of stepper controller boards and larger MosFets , if necessary.

 

Of course, everything will be bolted together and tested with static weights before anything with glass in it gets mounted. The top 3/4 plywood will probably become a ground board, a bolt and Teflon pads should do the trick. 

 

Have I made any fundamentally wrong assumptions here, might this work?

 

Frank

A bunch of dusty scopes...

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Edited by tincanandstring, 25 April 2019 - 01:06 AM.



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