On Sun, Jul 11, 2021 at 02:56 AM, alan137 wrote:
On Sat, Jul 10, 2021 at 12:56 PM, Nick Ambrose wrote:
1. Guide assistant said my backlash was 3500 ms so it did not recommend turning it on. It recommended guiding in one direction which did not work well. Brian V said that PHD cannot accurately measure BL on the spring-loaded worms, so not to enable the comp
I have a very long post describing the DEC axis backlash
/g/Losmandy_users/message/71205
Thanks! I am going to check this out.
Unless DEC affects the RA, then it is less of a concern right now, although might need some attention
When I imaged at DEC=60, RA was insanely good. Last night was DEC=30 and definitely a few excursions
The RA spikes still persisted and I did everything in software I could think of to tweak them, and nothing really had an effect.
Guiding was closer to 0.8-0.9 (DEC=30 not 60). Still OK but for the spikes
Things I can think of?
1. My guider scale is just not good enough and I need (at some point) to upgrade. Definitely possible
2. PHD2 "bug" -> could be just some weird thing. Who knows (somewhat unlikely ?)
3. I did change the weight, moving it further East. Its a 7 pound weight so I thought it would generally be OK to move.
I put it close to the end of the CW bar, and PHD2 kept complaining it could not move the star enough so maybe this has more impact than I thought ?
Maybe check balance again
4. Related to #3 - maybe it's possible Gemini is not getting enough power (since it couldnt move the axis with the weight moved)
I have an 18V power supply but maybe there is some issue here ? (It steps up from 12V)
5. Wires - Next time I will tweak my wires. I think they are tight, but if I try to re-route them and things change, then I will at least have something to look at
Other than that, I guess I don't have much to do except ignore them and assume my images are not affected.
I'm processing one from last night right now, so we will see
It doesn't feel satisfactory but at this point I dont want to tinker, and definitely don't want to void any warranty
I know these things are tough to debug but it doesn't feel super satisfying honestly
Upgrading the guider is definitely a "good thing" though. I think I can easily get an ASI290 and drop it into the current scope, which will help somewhat
Then later I could look into a better scope - but that's going to need a lot better mounting hardware than I have
