Another Guiding Request - Please help

[Sabalias]

Hi All,

I was wondering if a kind soul could lend me their wisdom regarding the attached PHD2 guidelog. First time out since April for me and something is very, very wrong. It's an HEQ5 Pro with Rowan belt mod; I've tuned out the backlash as much as I am able (but it looks ridiculously high in the log). I may have mucked up the PHD2 calibration (easy fix of course) or perhaps there is something else going on. Any ideas would be gratefully received.

PHD2_GuideLog_2023-09-04_153511.txt

PHD2_DebugLog_2023-09-04_153511.txt

Many thanks,

Stu🤯

Edited September 5, 2023 by Sabalias

[michael8554]

As you've already posted this on the PHD2 help site, you should try their suggestions before contacting us "amateurs".

Michael

[Mark2022]

2 minutes ago, michael8554 said:

As you've already posted this on the PHD2 help site, you should try their suggestions before contacting us "amateurs".

Michael

It's the Post Police!

[Sabalias]

15 minutes ago, michael8554 said:

As you've already posted this on the PHD2 help site, you should try their suggestions before contacting us "amateurs".

Michael

I posted here first as I didn't have a google account but then realised that I might benefit from the input there so I sucked it up and 'went google'. You never know though - someone here might have seen the same results specifically....

Stu

[vlaiv]

Looks to me like some sort of cable snag.

You have the same issue in both RA and DEC - which is unusual because DEC should really "stay put" without too much corrections, however you graph is almost the same in both axis:

I'm guessing that cable is pulling on OTA in such way that it moves both axis and when you do RA correction - it actually manages to make cable give a little and it takes more for DEC to recover - then cable tightens up again, RA correction manages to get a bit more slack of the cable and DEC slowly follows.

Binding would produce similar RA behavior but I'm not sure it would have the same impact on DEC though.

[Sabalias]

5 minutes ago, vlaiv said:

Looks to me like some sort of cable snag.

You have the same issue in both RA and DEC - which is unusual because DEC should really "stay put" without too much corrections, however you graph is almost the same in both axis:

 

I'm guessing that cable is pulling on OTA in such way that it moves both axis and when you do RA correction - it actually manages to make cable give a little and it takes more for DEC to recover - then cable tightens up again, RA correction manages to get a bit more slack of the cable and DEC slowly follows.

Binding would produce similar RA behavior but I'm not sure it would have the same impact on DEC though.

Thanks Vlaiv, that was what I wondered last night but I couldn't find anything obvious. I'll try again tonight to see if I can spot any external interference. I've reworked my backlash adjustments in case there is binding.

Stu

[michael8554]

Yep, for once us amateurs came to the same conclusion as the PHD2 guys, a cable snag.

They suggested setting up at the same Alt and Az, to see what may be catching.

Michael

[Sabalias]

1 hour ago, michael8554 said:

Yep, for once us amateurs came to the same conclusion as the PHD2 guys, a cable snag.

They suggested setting up at the same Alt and Az, to see what may be catching.

Michael

Indeed. I saw the answer in the PHD2 forum and was, at least, relieved to hear that it was something I could probably fix. I've checked and rechecked the backlash adjustments in case it's binding and I'll have a look at the scope in situ during daylight hours to see if there is a snagging issue. Will post back here in case it's something someone might find useful.

Stu