Having Problems with my autoguiding

[Darien]

Hello all,

Couple of days ago I went out to continue the imaging of the fireworks galaxy, My polar alignment was relatively ok so on that note I continued to do my 3 star alignment procedure in the area where the object was located. Despite that the my PHD software didn't show, "The RA and Dec axis are questionable"... my graph still looked a bit crazy and was unable to pull out a 200sec image and only a 180sec image. Any suggestions? or recommendations? I have the Celestron AVX mount.

[LightBucket]

Hi,

first of all what mount is it..? And you say your polar alignment is ok, it needs to be very close, not just ok..!

[Darien]

I have a AVX mount

[LightBucket]

4 minutes ago, Darien said:

I have a AVX mount

Sorry, yes my mistake...you did say I just did not see it...

I really think you need to get the PA as close as possible, and if still having issues, then start to look at other things...

[Ibbo!]

Also check balance and cable tugs.

[Darien]

Should it be east heavy?

[wimvb]

Have you read this?

https://openphdguiding.org/tutorial-analyzing-phd2-guiding-results/

My guess: backlash in DEC (at least partly)

[MarsG76]

Check Backlash settings on the DEC/RA motors... I had a spiking issue on DEC while autoguiding and adjusting the backlash on DEC seems to have solved it.

[Darien]

1 minute ago, MarsG76 said:

Check Backlash settings on the DEC/RA motors... I had a spiking issue on DEC while autoguiding and adjusting the backlash on DEC seems to have solved it.

I initially had my RA and DEC at 10 on back slash.

[Darien]

should I set RA to 0 and put like 5 on DEC +/-

[MarsG76]

1 hour ago, Darien said:

should I set RA to 0 and put like 5 on DEC +/-

that all depend on how much backlash you have... my backlash is at the level of 77 +/- on RA and +/- 43 on DEC. I came to that conclusion by attaching a 1/4" CCD (IS DMK21au618) to the and controlling the mount on a star using the arrow keys via NexRemote, and tweaking the numbers until the movement of the star was instantaneous/near instant in all 4 directions (of course tweaking one axis at a time). Directions to test were forward, forward, back, forward, back, back and repeat.

After I was happy with the response, the dec spikes have all but disappeared. On a good test night of guiding using the same CCD I was getting guiding accuracy of 0.81 RMS (previously 2.6ish) , that is at 2000mm on a 5.4um pixel... so equates to roughly 0.4 arc second RMS... Of course the proof will be in the imaging pudding. 

[newbie alert]

If you show the guide log  I'm sure someone can help..

You say you're using a avx? with what other equipment? Also PA needs to be done as best as the seeing allows,what method are you using?

[Darien]

On ‎9‎/‎25‎/‎2017 at 01:18, newbie alert said:

If you show the guide log  I'm sure someone can help..

You say you're using a avx? with what other equipment? Also PA needs to be done as best as the seeing allows,what method are you using?

This was from Last night. The PA method I'm using is a PA scope matching the Circumpolar constellations to the what is seen in the night sky making parallel to it.

[kens]

You'll never get good guiding without a good calibration. You've got serious issues there but it's hard to say more without seeing the actual log file.

[newbie alert]

Post up the guide log usually found in documents folder.. you say your PA was good..what was the RA and DEC errors  saying in the left hand box?