PHD2 won't calibrate "star didn't move.."

[kalasinman]

Feeling a bit frustrated after 3 nights of trying to get a calibration.

750mm reflector with Orion TOAG, QHY5L-II mono, on Ioptron ZEQ25GT mount

I see lots of stars in PHD2. I can see mount moves in response to calibration steps and manual guide commands.

I made a bad pixel map.

Cables supplied in metal box with new QHY.

I've manual selected, and let PHD2 select a star.

I have mount guiding speed at 1.0x.

I've used calculated guide steps (50) and selected guide rates as high as 5000.

Drift minimum to trigger correction .05 pixel.

I have spent some time tuning the mount, as I can get decent stars at 60 seconds or more unguided, and PA seems quite good from PA scope, but no drift align.

I've spent at least 5 hours over the last three nights with the same result.

Seeing is poor as low contrast (see attached), but I took a set of subs unguided last night with 1/3 throw aways. Just trying to get this sorted while the moon and seeing make bad imaging, so I can have fun when the dark returns.

Comments appreciated.--Jack

[Leveye]

When i first started using my Zmount with PHD I had this issue. In almost every situation it came down to the tension I had on the RA and DEC tension knobs.Seems some of these knobs and springs were cut too long and bottomed out to quickly. There is a mod you can do to double up on the springs under these knobs  ( smaller springs are inserted into the larger ones that come with the mount) so you don't have to crank them down so hard and for the mechanisms to function more easily and smoothly with less tension applied to them.

If your main tension knobs and springs are cut any longer than mine pictured here and in the other pictures you will want to replace the main springs and double up on the springs for sure. Some of the Zmounts have this issue.

Thanks goes out to Paul Chasse for finding this problem and coming up with this modification procedure and pictures. It worked like a charm for me. Highly recommended.

[kalasinman]

Very Interesting. Thanks Chris! Fortunately I just ordered the spring kit from Paul. In a week to 10 days I should have them. I'll look at screw length later today, just going out now.--Jack