Re: Help needed with Losmandy G11 Pmc8 System. #G11

Jennifer Shelly


Glad you figured out part of the problem was the grease.

Do you have the original worm and blocks or have you upgraded to the one piece worm block?  I assume you have the original worm and blocks.  If that is the case then adjusting these can be tricky because you have to loosen both blocks and keep even pressure while you pinch, pivot, and tighten the bolts up again.  This important because you want to make sure the blocks are square with one another and the pressure on the worm making contact with the bearings is enough so you will not have any side to side play.  

I suggest checking for side to side play before committing to the adjustment.  You will need the remove the top plate to expose the worm and blocks for each axis. Then with the clutches locked grab the counterweight bar and move it from side to side while watching the worm and the blocks.  If you see any side to side play then you will need to pinch both worm blocks with your fingers, slightly loosen the block that is farthest from the motor, pinch the blocks a little harder, and tighten the worm block.  Be careful not to shift the worm block up/down or twist.  Keep the block steady. Check again for side to side play.  If the side to side play is eliminated then that may be all you need to do.  If not repeat the process until the side to side play is eliminated.

If there is no side to side play then the worm is likely out of mesh with the wheel.  That involves slightly loosening both blocks while pinching them together, slightly pivoting the blocks upwards towards the side farthest from the motor, and tightening the worm blocks while holding and pinching the blocks.  You will wish you have three hands.  If you have someone who can help loosen and tighten the worm blocks for you that will save you from some frustration.  You will need to manually rotate the axis by hand to check for binding.  If any area of the manual rotation become difficult to do by hand then you will have to adjust your pivot downwards.  If it seems too easy to rotate by hand or if the worm seems too far from the wheel then you will have to adjust your pivot upwards.  You will likely have to do many iterations to get it right.

I hope this helps and good luck.

Jennifer Shelly
AstroPorch, VA

: ES PMC-8 G-11, ES PMC-8 iEXOS-100
Scopes: ES ED127 FCD-100, Askar FRA 400, ES Levy Comet Hunter, ES N208CF, QHY Mini Guide Scope, Solomark F60 Guide Scope
Cameras: QHY600M, QHY128C, QHY168C
Misc: MoonLite CFL 2.5 / High Res Stepper / V2 Mini Controller, Baader SteelTrack NT / SteelDrive II, Baader UFC, Optolong 2" L-Pro / L-eNhance, QHY CFW3-L, Baader 2” LRGBSHO CCD
Imaging Software:  NINA, APT, SharpCap Pro
Processing Software: PixInsight, Lightroom, Premiere Elements

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