900 Clutch Plug Help


rrumfield
 

After sometime off from using my 900GTO mount, I realized I needed to replace the clutch plugs on the right ascension unit.  I ordered the removal tool and new plugs.  The first plug removal was a learning experience and didn’t get totally removed, the other three were no problem.  I started to disassemble the R.A unit to get the first plug out.  I didn’t realize it was filled with plastic rollers.  At present I have been able to re-assemble it with two rows of rollers and a center axis that just doesn’t seem to now fit into the RA head properly.  Does anyone have the procedure to re-assemble the unit?  Should I send all back to Astro-Physics at this point?

Help,
Bob


Sean Curry <sxcurry@...>
 

Hi Bob,

I did this a few years back with my AP900 - all the clutch plugs were stuck and I disassembled it to remove them. I can't remember the exact process, but putting it back together wasn't too difficult - you shouldn't need to send it back to AP. If I remember correctly, George at AP sent me some helpful instructions, which I can't seem to find right now. One piece of advice he gave me was to keep all the Delrin rollers in a box so that the cat didn't start playing with them!

Maybe contact George and get his advice.

Sean

On Sat, Sep 26, 2020 at 1:42 PM rrumfield via groups.io <rrumfield=mac.com@groups.io> wrote:

After sometime off from using my 900GTO mount, I realized I needed to replace the clutch plugs on the right ascension unit.  I ordered the removal tool and new plugs.  The first plug removal was a learning experience and didn’t get totally removed, the other three were no problem.  I started to disassemble the R.A unit to get the first plug out.  I didn’t realize it was filled with plastic rollers.  At present I have been able to re-assemble it with two rows of rollers and a center axis that just doesn’t seem to now fit into the RA head properly.  Does anyone have the procedure to re-assemble the unit?  Should I send all back to Astro-Physics at this point?

Help,
Bob


rrumfield
 

Sean thanks for the reply.  I didn’t see your message until just now.  After a sleepless night, my wife and I started this morning and reassembled our mount.  After some trial and error we figured out how to put it back together.  We just put the motor on the RA.  I haven’t applied any electricity to the mount until I get some help with making certain the gears are meshed properly.  We only took the motor off by using the two unpainted bolts and it seemed to go back on the RA gear ok.  I’m calling Astro-Physics tomorrow to get some info on how to know the gears are meshed properly.

Bob


Roland Christen
 


I’m calling Astro-Physics tomorrow to get some info on how to know the gears are meshed properly.
Loosen the 2 bolts. Then gently snugh one of the two to use as a pivot while the other is still loose. Gently push the motor box into mesh while simultaneously tightening the loose bolt. Finish by tightening the other bolt. That's it, you are good to go.

It is not important to have very tight mesh in RA. Gentle mesh and even slightly loose will not affect imaging or guiding performance. It is more important to not have worm gears binding. You will get much smoother performance and lowest PE with gentle mesh and even slightly loose mesh. This is true of every mount ever made.

Rolando


-----Original Message-----
From: rrumfield via groups.io <rrumfield@...>
To: main@ap-gto.groups.io
Sent: Sun, Sep 27, 2020 12:09 pm
Subject: Re: [ap-gto] 900 Clutch Plug Help

Sean thanks for the reply.  I didn’t see your message until just now.  After a sleepless night, my wife and I started this morning and reassembled our mount.  After some trial and error we figured out how to put it back together.  We just put the motor on the RA.  I haven’t applied any electricity to the mount until I get some help with making certain the gears are meshed properly.  We only took the motor off by using the two unpainted bolts and it seemed to go back on the RA gear ok.  I’m calling Astro-Physics tomorrow to get some info on how to know the gears are meshed properly.

Bob


George
 

Bob,

 

Contact me directly.    I can help you with photos and instructions.

 

Regards,

 

George

 

George Whitney

Astro-Physics, Inc.

Phone:  815-222-6538 (direct line)

Phone:  815-282-1513 (office)

Email:  george@...

 

From: main@ap-gto.groups.io [mailto:main@ap-gto.groups.io] On Behalf Of rrumfield via groups.io
Sent: Saturday, September 26, 2020 3:42 PM
To: main@ap-gto.groups.io
Subject: [ap-gto] 900 Clutch Plug Help

 

After sometime off from using my 900GTO mount, I realized I needed to replace the clutch plugs on the right ascension unit.  I ordered the removal tool and new plugs.  The first plug removal was a learning experience and didn’t get totally removed, the other three were no problem.  I started to disassemble the R.A unit to get the first plug out.  I didn’t realize it was filled with plastic rollers.  At present I have been able to re-assemble it with two rows of rollers and a center axis that just doesn’t seem to now fit into the RA head properly.  Does anyone have the procedure to re-assemble the unit?  Should I send all back to Astro-Physics at this point?

Help,
Bob


rrumfield
 

George,

Sorry for the delay in getting back to you. My wife helped me and after a few fits and starts the RA piece is back together and all is well.  The new clutch plugs are installed and leveling should be a breeze.  The Declination system did not need the clutch plugs replaced.  I came home early today from work and we followed Rolando’s procedure to mesh the gears on the RA drive.  All drive directions work smoothly.  We can’t wait to put the weights back on and add our 130 f6.3 StarFire GTX.  If we have any problems I’ll contact you all, but fir now I think we are ok.

Regards,
Bob Rumfield