Weird issues with PHD2 (probably some speed issues) #S6


hendrik
 

Hi there, 

i am new here, hope i am doing this right :')

I have recently build two onstep drives, one mks and one Fysetc (for a diy startracker and for my LXD75). This works absolutely brilliant, in combination with a hypertune to the mount this is bang accurate and backlash is more or less not existant it seems (feels like a new mount, awesome). 

The only issue i am having:
When i start calibrating guiding in PHD2 my mount sometimes slews like 1 to 2 degrees on the first calibration step. I checked all my settings etc and everything seems fine. 
PHD suggests a 1550mS calibration step for the guiders focal length and guide speed on 0.5, i have tried reducing the calibration step to like 150mS and then calibration is fine till PHD is trying to compensate backlash while calibrating (it will do that forever and error out). 

My usual starting sequence is:

Polar align using sharpcap
Power on fystetc and wait for GPS lock
Connect the fysetc to the pc and make sure everything is fine in the ASCOM driver (coordinates, time etc), here comes part one that might be the issue (have not tried this yet). I use the ASCOM device hub (i find it convenient). 
I start tracking on the device hub. 
I go to the guiding tab in the webinterface of onstep and click 0.5 (noticing that no speed gets highlighted but that might be normal, also if there is a way to set this to default to 0.5 guiderate with some setting i would love to hear that since i have not found anything about it). 
I slew to my target using stellarium (connected to ASCOM via the device hub) and maybe align it a bit using the slew buttons on the device hub screen, the rate on the device hub shows Variable 1*sec. (this might explain the one to two degrees)
Start calibrating PHD2 and then the issues seem to start

Yesterday i got the guiding to work when i go into the web interface, click slew speed to slowest and then 1x again and after that i did no more slews using stellarium or the device hub and went straight to calibrating. 
Stopped guiding to aligning the target in my frame again using the controls in the hub, and it goes haywire again. Slewed back to target in stellarium then did the clicking of the speeds in the webinterface of onstep and guiding worked again.

(in both cases working and not working it does make no difference if i have PHD connected directly to the onstep ascom driver or to the device hub). 


Typing this i just realized that 1 Deg Sec in the hub  * 1550mS of PHD2 = about 1.55 degrees of movement which might be it. But i would like to know how those rates relate to each other, if i slew using a rate set in the device hub  or i slew in stellarium does onstep switch to that rate and stick with it? And am i right in clicking the 0.5 on the guiding tab in the webinterface to set it to the 0.5 that PHD2 expects the mount to be at. 

Thanks to anyone who can demystify this for me, if it means stop using the device hub then so be it :')

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