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I have a 12" LB as a second scope to take out and about. I replaced the springs in the primary mirror cell before I used it and have removed the locking screws, which are in the wrong place anyway. I also have Bobs knobs for the primary and secondary.
Why Meade would build a truss Dob with only 3 sets of tubes is beyond me. I think you will find that there is movement between the top and bottom end of the scope also. With my particular LB I found that the lugs on the clamping brackets bottomed out before the clamp tightened up on the truss tube ends.
I measured the length of the lug and the thickness of the truss tube ends with a vernier caliper and found that the lugs was close to 1/16" to long. I filed the lugs down until they were 1/32" less than the thickness of the tress tube ends. Now, when I tighten the clamps they actually lock the tube ends.
To test if this is a problem with your LB, leave the top end off of your scope and just tighten the tubes into the brackets on the bottom end of your scope. Gently try and rock the tubes, if like my scope was originally, they move within the tightened bracket then imagine what happens when the top end is in place and you are moving your scope in alt and az.
I have made many other mods to the LB and it works quite well now but I would still prefer to see them with 4 sets of struts instead of only 3.
Regards
Trevor
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