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Adjusting gear train and worm?

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#1 Whichwayisnorth

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Posted 19 April 2013 - 11:07 AM

Hope this is the right forum for this.
I was thinking about what "hypertuning" entails. I expect changing bearings out to better ones and having ring and worm lapped, polished etc. Also the gear box adjusted and all new and better grease used.

The question I have pertains to adjusting the gears in both the gear box and the worm. I know that some mounts actually have a end-user serviceable set of adjusters on the worm to tighten and loosen and change its tilt or slant. I did that on my CGE-PRO with good results. What is the *method* for testing those adjustments on the fly? Or lets step back, what is the initial adjustment before testing? Is there a known measurement of play between the teeth in the gear train? With a feeler gauge is there a measurement I should use? Or is it done by running an instrument that measures what the gears are doing while you tweak them? What are *harmonics* and how are they tested?

I assume it isn't as simple as running PEMPRO while turning a wrench but I wouldn't know where to start. I have several mounts to play with and I would like to start tinkering with them a little to see if I could improve them.

Thanks

#2 vorkus

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Posted 20 April 2013 - 08:17 AM

The first test is binding. You have to make sure the gears can make a full revolution without getting hard to turn. If you are adjusting a worm, then you better do a full rotation to check. If you are looking at the whole gear train, you can probably use your fingers in places to check. Other places you will have to run the mount and listen for stress in the motors. I did this to my Atlas. It takes time, but I ended up with a better mount afterwards.

#3 Raginar

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Posted 20 April 2013 - 08:57 AM

In the CGEM yahoo! group files section there is a good example written by Ed Thomas on how to adjust the worm on a CGEM.

Here is a link to how to do it on an Atlas:
http://www.astro-bab...m alignment.htm

When I would work on my CGEM, it was based on sound since it's hard to get to the gears themselves. Once you play with it, you'll get a feel for it.

Otherwise, consider just sending them to Ed. I found it really improved my CGEM and he is 'the' professional in that regards. It turned my average CGEM into a real performer, if only I'd learned not to try long focal length AP on it :).

Good luck!

#4 Cliff Hipsher

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Posted 20 April 2013 - 09:14 AM

Hope this is the right forum for this.
I was thinking about what "hypertuning" entails. I expect changing bearings out to better ones and having ring and worm lapped, polished etc. Also the gear box adjusted and all new and better grease used.

The question I have pertains to adjusting the gears in both the gear box and the worm. I know that some mounts actually have a end-user serviceable set of adjusters on the worm to tighten and loosen and change its tilt or slant. I did that on my CGE-PRO with good results. What is the *method* for testing those adjustments on the fly? Or lets step back, what is the initial adjustment before testing? Is there a known measurement of play between the teeth in the gear train? With a feeler gauge is there a measurement I should use? Or is it done by running an instrument that measures what the gears are doing while you tweak them? What are *harmonics* and how are they tested?

I assume it isn't as simple as running PEMPRO while turning a wrench but I wouldn't know where to start. I have several mounts to play with and I would like to start tinkering with them a little to see if I could improve them.

Thanks


What you need is a mechanic, ie, someone who knows about gear mesh, backlash, end play, run-out, etc. Also, this individual must have a finely tuned sense of feel and calibrated eye balls.

I spent over 20 years "tweaking" "small" gear trains in the Navy, and the only measuring devices I know of that will be useful are your Mark 1 Mod 0 fingers and eyeballs.

The point here is, you can see if a gear is not meshing properly, and by turning the gear train by hand you can feel the amount of backlash and slop, and using your sense of feel you can "measure" how freely the gear train rotates.

With that being said, you can buy either a full hypertune kit, just the instructional DVD, or you can have the mount done for you: http://www.deepspace...its_8_4227.html

#5 tomcody

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Posted 20 April 2013 - 09:33 AM

Just remember, all gears are not round, there will be a high spot (tight) and a low spot (loose) on the gear. Adjust for minimum clearance without binding at the high spot. This method protects your drive motors from damage.
Rex

#6 Whichwayisnorth

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Posted 20 April 2013 - 10:14 AM

My thought process is that if I can rock the DEC and/or RA and feel play in the worm/ring, I could adjust it to a point where I no longer feel the play in it but at the same time don't feel/hear any binding when I do a full revolution.

With regards to the gear train, if I could rock one Spacely Space Sprocket or Cogswell Cog and see/feel a bit of space between one and another, I could adjust those tighter. However that would increase the space between that adjusted cog and another. So I would have to re-adjust several. My goal would be to minimize the movement (backlash) in the gear train while at the same time not having any binding. I would also listen for the pitch to change to indicate that the teeth are not meshed properly. If I can get them smooth, quiet, and very little of any play in the teeth I'd have a winner.

However I have no idea if that kind of tinkering, if I get it to that point, would introduce more PE into the system. I should leave well enough alone but that isn't me. I need to tinker. I need to know how it works and why it works and if I can improve it.

Based upon the responses here I am starting to feel brave enough to give it a go.






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