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Old 08-12-2018, 05:53 PM
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multiweb (Marc)
ze frogginator

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G11 Backlash

I've been plagued with guiding issues for a few months now. Not a major issue at F/5 with the FSQ and its 3asp image scale but defintely with the C11 at 3m and even more with my CN-212. It's just unforgiving and lately it got worse. So I had to do something about it and pull my fingers.

I went through checking everything I could think of: the worm meshing, the end blocks, the bearings, changed gearboxes a couple of time, checked the couplings between the gearboxes and the worm to no avail.

Eventually I had to narrow it down to the coupling. Logically that was the only place that could have that much play. Problem with the new losmandy worm blocks is you can't see jack squat when they're mounted. The old system had a removable cover so you could inspect and tweak things with the worm mounted and meshed to the gear.

So this arvo I took the DEC worm block out and well... check the video below. I made a little red paint dot on the gearbox shaft as a reference marker. See the delay between the shaft rotation and the coupling starting to rotate when I apply pressure on it in the second half of the footage.

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Old 08-12-2018, 09:20 PM
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Peter Ward
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Humm...I'd have stripped the mount down, cleaned and re-lubricated all the bearings (the literally bind in very old grease). Same with the RA gear and worm (clean and re-lube) .

The coupling does have some designed-in play, but a drop of Loctite on the shaft would ensure the worm and motor shafts are not slipping.
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Old 08-12-2018, 09:41 PM
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multiweb (Marc)
ze frogginator

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I do that once a year. Never liked those couplings. They're a bit too short and there's not enough overlap for the clamps to properly hold the shafts. I ordered two new sets from huco. They're longer. That should do the job.
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Old 08-12-2018, 09:54 PM
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Peter Ward
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Quote:
Originally Posted by multiweb View Post
I do that once a year. Never liked those couplings. They're a bit too short and there's not enough overlap for the clamps to properly hold the shafts. I ordered two new sets from huco. They're longer. That should do the job.
Fair 'nuff
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