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  #1  
Old 09-03-2018, 12:32 PM
sharkbite
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DIY RA Motor advice needed

Folks...

Due to recent discussions about barn door trackers on this forum my chronic DIY condition came back.

I have an old powerseeker 127 that does not see any use.

I also have some slow gearmotors and controllers collecting dust.
(0.5 RPM jobs)

It occurs to me i am but a suitably fashioned bracket away from
having a motorised EQ mount, albeit a flimsy and wobbly one.
(I intend to remove the OTA and use it to mount the SLR for widefield.)

Does anybody know the gear ratio of the RA control on these mounts?
I just need to know how fast to run the motor.....

Any help would be greatly appreciated.

cheers,
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  #2  
Old 10-03-2018, 12:24 PM
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OzEclipse (Joe Cali)
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Google search for the gear ratios.
You can also make a double arm type IV with a 0.5rpm, 3/8W thread and a 10.25 inch drive radius. More accurate dimensions can be calculated if you want to pursue this.
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Old 11-03-2018, 07:16 PM
Bucky1379
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Hi back.
I (still) have a Powerseeker 127 but was never happy with it until I replaced the mirror with a parabolic (they came with a spherical with a corrector lens in the focuser). You should be able to find my posts here somewhere.
I also put steel rods and cement into the tripod legs which made it MUCH more stable.
But I gave up on the RA drive and just bought one. It was $50.
I've now got a EQ3 that I found on a hard rubbish collection. I am working out gear ratio's for an RA drive for it at the moment. I'm going for a 1 RPM motor but I'm not sure of the sprocket ratio yet or exactly how to mount it. It also needs a way to disconnect it for fast manual slewing. There are some forum discussions here about it.
Maybe we can sort out a solution together.
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Old 11-03-2018, 08:02 PM
sharkbite
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Thanks guys

After my friend Google came up with little.....

As it happens the 127 ra markings are in hours.

To advance the ra 1 hour takes 4 turns of the ra knob.

So even my half rpm is screamingly fast.

I'll see how slow I can reliably control it and post the findings here.
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Old 13-03-2018, 12:53 PM
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bojan
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Have a look here... it may be of some help.

Last edited by bojan; 14-03-2018 at 01:08 PM.
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  #6  
Old 14-03-2018, 12:56 PM
sharkbite
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Quote:
Originally Posted by bojan View Post
Have a look here... it may be of some help.
Hi Bojan....

this link is all about eyepieces?

its called "Swan eyepieces feedback"
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Old 14-03-2018, 01:07 PM
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Quote:
Originally Posted by sharkbite View Post
Hi Bojan....

this link is all about eyepieces?

its called "Swan eyepieces feedback"
Ouch.. sorry... no idea how it happened (I must have been doing two things at the same time).

Here is the proper llink:
http://www.iceinspace.com.au/forum/s...&highlight=EQ3
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