PHD Guiding help (wont calibrate)

[Mick UK]

I keep getting the following error message using PHD..it stops calibrating at 61 every time.

"phd guiding RA calibration failed star did not move enough"

any help greatly appreciated:(

[steppenwolf]

Try clicking on the 'brain' icon and increasing the 'calibration step (ms)' figure to something around the 1500 mark - this commonly resolves the issue as it increases the amount of movement applied to the mount during calibration.

[Mick UK]

Thanks Steve,

Much appreciated:)

[BlueAstra]

Happened to me once when the cable came slightly out of the guide cam and it lost comms with the mount (it had a guide output). Still sent a picture to the laptop so it was really confusing.

[SlipperySquid]

Also had this problem mate last night! Was my first try at guiding and I spent 6 hours fiddling about and swearing! it was great.

Anyway I was having the same problem nothing I did would get it to calibrate UNTIL I looked under the MOUNT header, then I chose "on camera" I think that was it anyway!

and then it would guide! and calibrated within about 7 steps.

[Mick UK]

Cheers all, i will report back on which idea worked in about 5 months when the sky decides to clear!

[RobH]

Another trick is to nudge the mount to the north before starting calibration. The first DEC calibration command is North and doing this takes up the backlash. With my old LX200, DEC calibration would sometimes fail if this wasn't done.

I suppose the same applies to RA, but I never had any trouble with this and can't remember which direction the first calibration move is.

Cheers

Rob

Edited August 6, 2010 by RobH

[Mick UK]

I havent done any guiding before so do i assume that every time i move to a new target i will have to callibrate PHD?

[SlipperySquid]

Dont think you HAVE to but it's best I think.

Plus it literally takes seconds to calibrate...mine takes less than a minute now I ahve it set right!

[Uranium235]

Ive had the same error message before too, and that was down to not plugging the st4 guide cable in fully... doh!

I only re-calibrate if im imaging a completely different part of the sky - eg: going from M101 through the meridian to M31. If its just a short(ish) jump, then no need to. Good polar alignment will help a lot... oh, and choose "north" or "south"... not "auto" as you will get backlash. Choosing north/south or means that the gears only need to correct in one direction in DEC - its just a case of figuring out which way it likes to drift. For me its North on the East side of the meridian, and South for the West.

Let us know how you get on anyway, and try not to get too steamed up when it wont guide for toffee....lol.. it happens to us all at some point.

Edited August 7, 2010 by Uranium235

[Steve 1962]

Hi Mick

I've had similar problems in the past, the solutions in my case were (on different nights) making sure that;

The correct cables are properly connected - I tape mine into place with duct tape these days just to be sure.

The mount is correctly selected in the Mount menu - "Ascom" when I used to guide with a webcam via EQMOD and "On-Camera" now that I've got a QHY5V connected to the ST4 port on the mount.

The calibration steps long enough - mine are set to 1200mS.

I only generally re-calibrate if I move the mount to a completely field of view of the sky and I seem to get away with it most of the time.

Hope this helps

Steve

[Ant]

Try clicking on the 'brain' icon and increasing the 'calibration step (ms)' figure to something around the 1500 mark - this commonly resolves the issue as it increases the amount of movement applied to the mount during calibration.

I had that error message loads of times - Steve suggestion fixed if pretty much every time.

Make sure that the wires to the scope are not snagged and that the scope is balanced (and both axis locks are locked).

Cheers

Ant

[IvanT]

I was playing with PHD tonight and couldn't get it past the North alignment step (without going into manual mode). Kept failing at 61 with "Dec calibration failed turn off Dec guiding".

I tried upping the step ms setting from 750 to 1500 to 2000 but it didn't make a difference to the North cal problem (it did make East West cal a lot faster). When calibrating it did the East, West & Backlash without a problem but I didn't any movement at all when doing North. I used the manual mode to nudge it North which got it past the calibration and it started guiding. After < 2 mins, it started beeping & I could see it was loosing tracking on the guide star.

Reading about it, a common problems seems to be poor polar alignment, so I re-checked & confirmed my drift alignment. Drift alignment kept a star pretty much in the centre of the reticule for a couple of mins before it started to drift out, so I don't think that is the problem.

My guide camera is a QHY5, any suggestions as to the settings I should use for that setup?

Having sorted my a noob focus problem with the finder/guider this is the next one for me to overcome. One step closer to guided AP and Christmas hols approaching. I really want to get this one sorted so that I can concentrate on honing my AP skills.

As usual, any help/suggestions greatly appreciated.

[SlipperySquid]

Have you tried removing and reinstalling the camera drivers and phd? maybe need updated ones. I'm using PHD version 1.12.0 and the latest drivers for my Orion Starshoot autoguider (nearly the same as the qhy5) and have no problems in windows 7? Just an easy idea to start on if you havent tried it already? Is there anyone you could borrow another st4 cable from to see if it is your cable?

[adamsp123]

Ivan, have you checked your DEC balance both with the scope horizontal and scope vertical, if you have too much of an inbalance then DEC won't calibrate in my experience.

Also I have a cable issue as well, corroded contacts, I replaced them with Astronomiser quality ones and never had a problem since.

Edited December 23, 2010 by adamsp123

[IvanT]

Have you tried removing and reinstalling the camera drivers and phd? maybe need updated ones. I'm using PHD version 1.12.0 and the latest drivers for my Orion Starshoot autoguider (nearly the same as the qhy5) and have no problems in windows 7? Just an easy idea to start on if you havent tried it already? Is there anyone you could borrow another st4 cable from to see if it is your cable?

I've only just recently installed it for the first time. It's ver 1.12.0 It is Win 7. Thanks for the suggestion though.

[IvanT]

Ivan, have you checked your DEC balance both with the scope horizontal and scope vertical, if you have too much of an inbalance then DEC won't calibrate in my experience.

Also I have a cable issue as well, corroded contacts, I replaced them with Astronomiser quality ones and never had a problem since.

I'll re-check it, I have it balanced with the 1000d etc in place but last night I must admit I didn't have the 1000d connected and hadn't re-adjusted the balance to compensate. Thanks for the suggestion, I give it a whirl.

[carastro]

I had this problem recently and it toook me ages to figure out what the problem was.

It was moisture having got into the Guide camera not giving sharp enough stars (through leaving it in the Observatory), won't make that mistake again. Duh!

The joys of trying to fathom out the cause were a real PITA.

[IvanT]

I had this problem recently and it toook me ages to figure out what the problem was.

It was moisture having got into the Guide camera not giving sharp enough stars (through leaving it in the Observatory), won't make that mistake again. Duh!

The joys of trying to fathom out the cause were a real PITA.

So it was able to calibrate East West & clear Dec Backlash, but failed to calibrate North due to moisture?

[carastro]

So it was able to calibrate East West & clear Dec Backlash, but failed to calibrate North due to moisture?

The problems varied, starting with poor guiding, then deteriorated into not being able to calibrate at all, then as it was recovering (drying out) it calibrated RA but would not calibrate North Dec.

Eventually it went back to working OK with no changes made.

Carole

[IvanT]

Hehe, bet that was a fun night :-)

Sounds like there can be lots of reasons for what appears to be a common problem. Think I've eliminated bad polar alignment, next on my list is balance and I'll keep moisture buildup in mind also.

Thank Carole

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[carastro]

Hehe, bet that was a fun night

It was a "fun" 3/4 weeks!!!!

I've still got some hair left!!

Good luck

Carole

[IvanT]

Checked my balance last night and and found it was quite a bit top heavy camera end of the scope. Corrected that, tried calibration again (up at 2500ms), had to nudge the scope north with my hand to to get Dec cal done.

Now don't all laugh, this may be very silly, but, should the sidereal tracking on the HC be turned on or off while guiding? With it off I found that PHD calibration worked without any intervention. After it went to guiding though, the guide star tracked off the left edge of PHD until eventually loosing tracking.

Has the tracking rate option on the HC to be set normally?

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[dmahon]

Tracking should be turned on. If it isnt, and guiding is working, the guiding should keep the stars reasonably still anyway - but guiding is intended as a correction to tracking, rather than to be used instead of.

If PHD won't calibrate, the first check is that PHD is actually talking to your mount (either via "on-camera" ST4, via ASCOM pulse guiding, or whatever). I think the way to do this is to use tools, manual guide - and then move the scope.

[DIYASTRO]

Just wondering... is it possible to test system to check if GPUSB is making connection etc using the simulater instead of a real camera when doing calibration? I know that the GPUSB check programme would do this but will the mount callibrate when using the simulated camera

Boyd