PHD doesn't move my mount in RA but will move it in Dec

[John Coffin]

Last night I tried out my new EQ8. I am using EQMOD connected to my PC via an EQdirect connection to the socket marked 'handset'. The EQdirect cable is routed through a Pegasus Astro UPB v 3. I am using an off axis guider with my C11 and a focal reducer x 0.63

I have no problem slewing the mount using EQMOD but when I tried perform a guiding calibration in PHD2 it failed because the star wasn't moving  enough, any movement was due to tracking errors and seeing. I was using the calibration assistant and the mount was at zero declination and 5 degrees from the meridian.

I've tried increasing the calibration step from the recommended 150ms to 2000ms and this made no difference. I've tried reinstalling PHD2, and also the latest development version but still no joy.

I then tried guiding manually in PHD2. I could move the mount in Dec but not RA. I checked that the clutch was tight enough.

I've had not trouble with PHD2 with my AZEQ6 and have been performing spectrometry of symbiotic stars for many years and getting average RMS between 0.6 and 1.2 arc seconds. I upgraded my kit to a C11 and a side-by-side mounted refractor in order to perform simultaneous photometry with the spectrometry. My AZEQ6 had trouble coping with the extra weight, so I bought the EQ8. 

These are screenshots of my EQMOD settings. 

 

Does anyone have any advice please? 

I've also attached the logs from PHD, sorry there are so many. I wasn't sure which ones are relevant. 

Thanks, John Coffin 

[Bryan]

John:  Just for future reference.  If you use the built-in log uploader (see How to Get Help with PHD2 at the top of the forum), then you can choose the specific logs for the date that you are investigating.  It is a single link to the Guide and Debug logs, which you can copy and paste.  

At times, the Debug log, in particular, will be too large to attached to a post.

Bryan

[Bruce Waddington]

This is most likely to be a problem with the RA axis on the mount. The software is working correctly, the mount driver isn't reporting any errors, but obviously the axis isn't responding.  I think you will probably need to open up the RA drive system and figure out why the axis isn't moving smoothly and easily.  The pulse guide commands are very short and result in only small amounts of energy being applied to the RA motor.  This is why being able to slew the mount doesn't tell you anything about its ability to be guided - the amounts of energy being used will often vary by a factor of 50x.  A common source of problems like this is that the drive system it meshed too tightly but there could be other problems such as lack of lubrication or accumulated dirt on the gears.  Obviously, you also need to confirm that your cable routing doesn't interfere with movement of the axis when you're pointing near Dec=0.

Hope you can track it down quickly,

Bruce

[John Coffin]

I've spoken to Dave Woods from Dark Frame who rebuilt this mount from new for me. It is likely that the drive belt in RA is a little too loose, so I have tightened it and am waiting for a clear night. 

Thank you for your help with the diagnosis and I take your point about the correct way to upload the log files. 

John

[John Coffin]

I've finally cured the problem. There appears to be a bug in the latest motor controller firmware update 3.45

After reverting to 3.39 my EQ8 responded normally to guiding commands. I am using EQMOD, I don't know if the bug affects Green Swamp Server.

Thanks for your advice.

[John Coffin]

Just to be clear, tightening the driver belt for RA didn't help.