On 2/7/2025 11:41 PM, avishekaiyar via groups.io wrote:
No matter how much I tighten the RA clutch knob I am unable to fully lock the RA axis movement (and I really tightened the clutch). The Dec axis is fine....I am able to fully lock down that axis when I tighten the Dec clutch.
The clutches are just that.... friction clutches.? If any grease has made it onto the friction surfaces (and it will) they cannot be "locked".? NOR SHOULD THEY.? The more you tighten the clutches the more load you put on the thrust bearings.? The thrust bearings use cylindrical rollers that roll in a circle.? And if you think about the geometry of a cylinder rolling in a circle, it will be obvious that it CAN'T unless one end or the other slips.? And if they slip unevenly, you can get RA jumps.? So the tighter the clutches, the more drag and unevenness from the rollers.
Once I realized this I tried running with very loose clutches and all my RA jumping went away.? I don't know if it made a difference but I also cleaned the thrust bearings and re-greased with MP-50 since in essence, the rollers are a high pressure sliding interface.? I normally tighten until I feel contact and then go a maximum of 1/8 to 1/4 turn farther.? But, I can even run with the RA clutch fully loosened..... the rig is well balanced (that is key) and simply the weight of the rest of the mount and load is sufficient to provide enough friction.
My $0.02 anyway.
Paul
(another one)
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Paul Goelz
Rochester Hills, MI USA
pgoelz@...
www.pgoelz.com
