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LXD75 R.A. Drive Worm Gear problem - Advice?

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#1 rnoelle

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Posted 09 March 2009 - 09:25 PM

Greetings:

My RA drive mysteriously quit operating (moving) after doing a routine alignment. Upon investigation, I find that the worm gear simply is not engaging the main drive gear. The worm gear shaft is straight and turns smoothly without play. I've tried various adjustments on the little worm gear bracket and it will sometimes turn the main gear but then lets go. The main gear teeth are concave ... are they supposed to be?

Any enlightenment would be appreciated. I know just enough to be dangerous!

--Bob

#2 David Pavlich

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Posted 09 March 2009 - 10:38 PM

Hmmmm...that's odd. There should be enough adjustment to get the gears to mesh. Are you sure that the motor/gear is engaging the worm? There isn't a whole lot of wiggle room for the two gears to mesh.

The RA teeth are slightly concave. Also check to make sure the one of the gear set screws hasn't loosened up or sheared off.

David

#3 Skywatchr

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Posted 09 March 2009 - 10:43 PM

That's what it sounds like, the set screw came loose or sheared on the aluminum spur gear.

Jeff

#4 rnoelle

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Posted 09 March 2009 - 10:53 PM

Thanks for the reply David ...

I first opened the little door to see that drive gear was in fact turning the other gear thats connected to the worm shaft. I then removed the motor housing to expose the worm gear bracket. All the screws were tight, but when I turned the worm gear by hand, the main drive would not move. I removed the worm gear bracket to inspect and it all looks good to me.

The worm gear bracket appears to be correctly held in position by the two outer screws, I am not sure about the proper tension adjustment of the center one, but it was tight.

Does that help?

#5 rnoelle

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Posted 09 March 2009 - 11:14 PM

Jeff, thanks to you too for jumping in here.

Ah, I think I just figured this out ... it must have been the screw adjustments on the worm bracket. When I originally reassembled the worm bracket I tightened the outer screws. In that position, the worm would *not* <--(edit) fully engage the drive gear. The trick is to have those outer screws a little loose and then apply all the tension with the center screw. Everything seems to mesh very smoothly now.

Does that sound correct, or could I have other issues?

#6 Skywatchr

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Posted 10 March 2009 - 03:27 PM

As long as it works!

Jeff






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