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Quick question on counterweight positioning

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4 replies to this topic

#1 LoveChina61

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Posted 03 April 2024 - 02:54 PM

Does it matter if the counterweights are on the top front edge of my LX200 Classic’s OTA instead of being underneath the OTA as the original Meade counterweight kits show it to be?

Mike

#2 WaveGuide

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Posted 03 April 2024 - 04:39 PM

Hello Mike,

My counterweight is on top of the OTA and the guidescope is underneath. It really doesn't matter, the essential thing is that the ota is balanced with ota both horizontal and vertical. I have mine biased very slightly east-heavy using a large elastic band, fork arm to pier (it's on a wedge). Lots of videos/tutorials online about balancing an LX200 type scope.

Cheers,

- Jack


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#3 DarkDesertSky

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Posted 03 April 2024 - 04:53 PM

   I would be very careful when loosening the clutch in that configuration as the scope may "flip", wanting to put the heavier counterweight system underneath the balance pivot point (the forks tines), resulting in the diagonal/eyepiece or image train combination striking the fork base with a lot of force. Physics people can jump in and describe the actual terms better than I. For lack of better words, with the weight system below the pivot point, it will have a tendency to remain at or near that point since gravity is pulling down on it and its already near its lowest point. With the majority of the weight above, gravity still wants to pull the heavier side downward, but it will have much more rotational travel (inverting itself, spinning top to bottom). I hope that makes sense...just trying to help. Is there a reason that your counterweight system can't be attached underneath?

 

Edit: This assumes that your counterweight system is heavier than anything attached to the bottom side, such as guide scope in the post above. 


Edited by DarkDesertSky, 03 April 2024 - 05:33 PM.

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#4 LoveChina61

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Posted 03 April 2024 - 06:32 PM

Thank you both very much for your comments. Very helpful as I plan to do a late-nighter to get everything going today.

Mike

#5 MikeBY

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Posted 04 April 2024 - 08:55 AM

You will want to position the counterweight on the opposite side of your guide scope or anything else you have piggybacked  on the main OTA. The purpose is to keep the center of mass close to the intersection of the two rotational axis regardless of the position of the OTA. You are balancing in 3 dimensions. 

 

Then, it's a good suggestion to create a small offset to keep the gear train loaded in the same direction at all times to avoid backlash float or shift. There are different ways of doing this, but that is a different issue.


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