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G11G, new this year.

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One thing I've had a time with is balancing RA. I get a good feel in DEC even with lighter payloads, but I find both sides of RA are just sticky enough to make getting very good balance difficult. I am wondering how others deal with this. Is there such a thing as upgrading those bearings?

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What I have done a few times is lower the altitude to nearly parallel with the ground and then it's loose enough to get great balance. I messed with the idea of tilting the tripod temporarily because cranking the altitude that much is a bother, but yeah, bad idea. Did not manage to topple it if you are wondering.

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I do not believe it is the clutch per se.?

As my G11G got "broken in" it got easier to balance. Here is what I first did. Lower the altitude to nearly parallel with the ground, you can use 1 hand to turn the knob and the other hand to hold the weight of the counterweight rod. This takes the weight off the altitude rod and makes it a lot easier.

The next is a little tricky. Unscrew the altitude clutch knob about 1/2 inch. Then push the end back in about 1/4 inch. If easier, pull from the front. It helps to have someone to hold the rig, if you have to pull a little bit harder. This will keep clutch from touching, and it will be riding only on the bearings.

On Wed, Sep 4, 2024 at 07:03 AM, Ed Harp wrote:

G11G, new this year.

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One thing I've had a time with is balancing RA. I get a good feel in DEC even with lighter payloads, but I find both sides of RA are just sticky enough to make getting very good balance difficult. I am wondering how others deal with this. Is there such a thing as upgrading those bearings?

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What I have done a few times is lower the altitude to nearly parallel with the ground and then it's loose enough to get great balance. I messed with the idea of tilting the tripod temporarily because cranking the altitude that much is a bother, but yeah, bad idea. Did not manage to topple it if you are wondering.

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I do not believe it is the clutch per se.?

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For GOTO use payload balance is not as important as most people think. As long as your servomotors are not struggling while slewing the payload uphill on either side of the meridian you are fine.?

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For a visual user working the mount in PUSH-TO mode balance is important so the clutches can be left loose enough but with just the right amount of drag so the mount can be pushed with two fingers and yet stop and still have enough grip for the RA servos to track the mount.??

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Indeed, Chip. It's interesting to consider the load an electric motor can apply when using 1/10 amps with a 9000 to 1 gearbox. Without clutches, the occasional imposed condition would destroy the gearbox. Calculating this, {1.2 W * 0.001 kW/W * 738 ft-lbs/sec * 9000 sec = 7800 foot-pounds}, shows that even with a 99% loss or less current, there's still the potential for significant torque.

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The motors do not stall or lose encoder position before the clutch, fully engaged, slips. Leveling with a clutch that is free yet under some pressure necessitates estimating the force needed to overcome friction in the direction of rotation with the Dec horizontal, rather than at the balance point.

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Even so, we each use different OTA/counterweights at various declinations, and some might find the wavy washer aid from Losmandy beneficial to help balance their setup by reducing the disengaged load.

Thanks everyone.

I get quite better guiding when my very old 1995 G11 is very carefully balanced (needs good polar align too ). It has fresh grease and sometimes gives me below 0.5arcsec guiding, on good nights.?

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Only trick I use is for Dec balance, its done with AD set horizontaly, 90° on the side.

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Yes, with the RA horizontal for balance and great polar alignment, I am getting guiding at 0.4" most of the time.

On Wed, Sep 11, 2024 at 01:49 AM, Ed Harp wrote:

Yes, with the RA horizontal for balance and great polar alignment, I am getting guiding at 0.4" most of the time.

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I have been doing a lot of this stuff before I found the page I wish that I had found it sooner! Look at the balance, clutch washer assembly order and orthogonal alignment tips and follow his examples.?

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https://www.wilmslowastro.com/tips/g11gemini.htm

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Let me know if you have questions.?

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