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Meade LX850 RA slew issue

Meade mount DIY equipment beginner
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5 replies to this topic

#1 balotin

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Posted 16 February 2020 - 12:26 PM

My mount isn't used that much but recently I went to a 12inch OTA from a 10 inch. During east to west slews the mount starts to jitter as the load comes down on the west side of the mount. Slews west to east are fine.

I have had the gear covers off and the motor to worm gear train seems fine- no mesh issues, no chewed up teeth.

I have not looked at the mesh of the worm to ring gear as I cant quite figure out how to get to it.

I have checked the balance of the RA axis with a spring scale and balance is good to a few ounces difference.

I know of one other Cn'er who has this issue as well.

Any advice appreciated, thanks!

#2 Spacetravelerx

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Posted 17 February 2020 - 11:27 AM

Hello Joseph,

 

It still sounds like a balance issue - I have experienced this too. An easy way to check is to gently apply a force with your hand on say where the camera is until the jittering stops.  This tells you what the counter force needs to be.  Anytime there is any equipment changes this will impact your balance.  

I have also noticed the slewing problem may be related to temperature. One thing I did with my other LX850 was just change the maximum slew rate to a slower rate.  This made moving to a new target painfully slow in the winter, but the jittering/vibration went away.


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#3 Starhawk

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Posted 18 February 2020 - 12:53 AM

It’s going to be in the worm mesh.  So, you get to find out how to adjust it. Note, you’ll need to drive al, the way across 180 degrees of mount movement to make sure it isn’t tight at any point- set the mesh where it is tightest or else you can burn out a motor.  See if you can get instructions on this model. 
 

-Rich

 

My mount isn't used that much but recently I went to a 12inch OTA from a 10 inch. During east to west slews the mount starts to jitter as the load comes down on the west side of the mount. Slews west to east are fine.

I have had the gear covers off and the motor to worm gear train seems fine- no mesh issues, no chewed up teeth.

I have not looked at the mesh of the worm to ring gear as I cant quite figure out how to get to it.

I have checked the balance of the RA axis with a spring scale and balance is good to a few ounces difference.

I know of one other Cn'er who has this issue as well.

Any advice appreciated, thanks!



#4 Karni12

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Posted 19 February 2020 - 09:45 PM

I had a 12" LX850 and had similar issues. I had to send it to Meade for repair. It burned out my motor. When I got it back 2 mouths later it did the same thing. That was when I put that garbage up for sale.



#5 schmeah

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Posted 22 February 2020 - 10:37 AM

I had a 12" LX850 and had similar issues. I had to send it to Meade for repair. It burned out my motor. When I got it back 2 mouths later it did the same thing. That was when I put that garbage up for sale.

I am always curious what the ad looks like when someone who freely describes his item as garbage on these forums puts it up for sale. 



#6 Donnie D

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Posted 20 March 2020 - 10:32 PM

Interesting that I was actually looking into purchasing the LX850 12".  Now, since I do not own one, but have read the instructions, please bear with my ignorance here as I am just as interested in this problem as the next guy. Here is my comment/question:  Ok, so the extra 'saddle plate' that they are referring to, to mount the Starlock. They say something in the manual about mounting the Starlock (scope) to the OTA on top instead of on the 'side saddle" - would this have anything to do with the slewing problem?

I noticed even at the beginning of the manual, they show two pictures of the rig. One has the Starlock Scope on the side-mounted and then another picture showing the Starlock scope on top of the OTA !  So, which is the best method. When or If I get this scope, then I would take it that I should mount the Starlock on top of the OTA and not use that side saddle 'thing" . Sorry for the ignorance here folks.  The point I guess I am trying to make is that it all comes down to correct balance. But, I am thinking that the balance should NOT have to be that much critical to be causing this problem.

I did own a 9.25 Edge before (sold it) and some of the time, it made the most oddest of grinding noises as it would pan through slews.

Oh, forgot. They did mention way into the later part of the manual to mount the Starlock guider to the TOP of the OTA for 12 and 14 inch models.

 

Donnie


Edited by Donnie D, 20 March 2020 - 10:34 PM.



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