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On Tue, Feb 25, 2025 at 03:41 PM, <tshelley@...> wrote:

Paul: The drive noise is what you'd hear if you touched the pointed end of a phillips screwdriver to a portion of the worm gear housing and the other end to your ear. I use the mounting bolts to avoid any moving parts. Otherwise the guiding is totally silent.

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Michael: This is some good advice. I'm afraid that it will be some time before I can get back to the hobby, darn that life thing.

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"Do you have a wavy washer in your clutch assembly? That, along with too much pressure could explain why the wear is both wavy and uneven." Yes I have the wavy washer, in the correct order. Now as to too much pressure, that's a possibility. My hand strength is very low and I've had to use a wrench to tighten the main axis clutches. So I could be putting too much pressure on the bearings. I tighten until I cannot move the scope manually.

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"I'd be most suspicious of binding in worm/ring gear interface."

I've spent a lot of time tuning this particular parameter, but I can certainly back off a little and see what happens.

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Thanks again for the great advice. I'll post again when I can do some controlled work with the new rig.

Tim

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Hi Tim,

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A lot of MBY's advice is excellent but you should NEVER use a tool or wrench to tighten the clutches.? Overtightening the clutches using a tool or strap wrench is one of the best ways to warp the thin aluminum clutch plates that are attached to the large axles.? You should never be able to fully lock up the Losmandy mount clutches, they are designed to slip on purpose.? If you do use a strap wrench you'll can distort the clutch discs permanently.? This will require having the clutch face reground or maybe flycut to correct so the clutches have the full friction surface area available.??

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Excessive clutch pressure also increases the load on the upper thrust bearings and can damage the thrust bearing races / washers. The standard part number for these thrust bearings are rated to approx. 6,600 pounds which sounds like a lot but the amount of pressure put on these bearings is very high when you crank down on the clutch knobs.? Think about it, how much load is being placed on these bearings once you take up all the slack in the RA axle then turn the RA clutch knob 1/4 of a turn against basically a solid block of aluminum and stainless steel?? Screws are very simple but also very powerful machines.? I don't know the thread pitch of the clutch knobs but that will be a lot of force with the only really compressible part being the plastic clutch disc.? Now I feel the need to go put a pitch gauge on the threads and calculate the load on those bearings.? But trust me it is quite high.?

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As far as spring loaded worm block adjustments go you want to use the lowest spring pressure that keeps the worm teeth fully engaged in the worm gear mating surface, no more.? This is a sort of dynamic load but you can get it to work for a variety of payloads and polar moments.? When adjusted just right the worm will be engaged but you will see the worm block moving slightly as the mount tracks.? You will also want to adjust the worm block lifting bolt to minimize the current used to get past the tight spot in the worm / worm gear.? I use an ammeter on my bench power supply to adjust my G11G and GM8G mounts and it works very well.?

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I recommend using the Losmandy grease kit but an easy to find, probably better grease is Superlube with Teflon spiked with 15% by weight molybdenum.? I have been using this blend for over a year and cannot say I see any improvement in wear on the thrust bearings or worms vs the standard Superlube with Teflon.? I have used Superlube with Teflon for decades and it has been the best mount drivetrain lube for several reasons.? Wear is very minimal, the pure synthetic base oil has minimal to no separation in extreme desert heat.? This means that when applied correctly Superlube won't melt, run off and migrate to contaminate your clutches.? Superlube also doesn't get stiff when cold and retains its very low start up torque which BTW is much lower than MP50's starting torque. These traits matter for consistent PE in hot or cold while guiding.? The easy to see translucent white grease shows contamination easily helping you to know when maintenance is needed.? Food grade grease is reasonably safe to handle.? ? ? ??

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