On Wed, Mar 12, 2025 at 03:32 PM, DaleN wrote:
Better! A bit of follow-up to my GM811G with poor Dec guiding for SVX140T:
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I followed a few of the great suggestions, namely reducing the CW moment arm and Dec guiding aggressiveness.
i ordered a 21 lb CW, and installed it at the top of the shaft, with an 11 lb up against it. A 7 lb midshaft for balancing. So now at 39 lbs CW rather than 29, but much higher on shaft, so moment arm is greatly reduced.
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dialed back the Dec Aggression to 60, and stretched the guide imaging to 3 sec from 1.5. Got down to ~.45” both RA and Dec for a while, but more generally .7” ish for each for several hours, with low eccentricity. Much better. I’ll see if I can’t dial that in better now.
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many thanks for the suggestions!
CS, Dale
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There are differing schools of thought on this based on what I have observed others doing and when asked why I got a lot of different answers.? IME ideally you want to use enough counterweight so you can position the counter weight mass up as high as reasonably possible (mechanical interference is the obvious limit and varies based on where you are) and still achieve good balance.? I use the small 7lb. counterweight on the end to make fine adjustments easier.? Using this method requires having the most counterweight available.??Of course the heavier the payload the more counterweights end up on the shaft and they also tend to naturally move up the shaft which is ideal.
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Chip Louie Chief Daydreamer Imagination Hardware?
Astrospheric Forecast - South Pasadena, CA?
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Chip Louie