Author Topic: Ascom Guidance?  (Read 222 times)

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NoelC

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Ascom Guidance?
« on: Jul 18, 2017, 08:27:45 »
Anyone got experience of Ascom troubleshooting?
My mount does not appear to be accepting Ascom Pulse Guide commands consistently.

I have been having immense problems using Ascom pulse guide (slew, position and track work fine). It sort of guides but produces very poor results which I assumed was mechanical. I have suspected the mechanics for the last year and a half, but finally ran it under manual guide with the Ascom monitor on and realised that only about one in ten guide commands are being accepted (isguiding=false).  When true; the mount moves, when false it doesn't.

Have tried setting the port buffer to 64 bits, changed priorities leads and connections.
Am using an FTDI EQDIR setup; have not actually run ST4 guiding to check if that works (yet).
The mount is an old HEQ5 Pro.
Synta mount, a bunch of telescopes and a shed (on wheels).

RobertM

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Re: Ascom Guidance?
« Reply #1 on: Jul 18, 2017, 09:27:08 »
There is the imaging session at my place.  These sessions are specifically for this type of Astro imaging issue.  You can either bring your heq5 or use my heq6 with your laptop and leads.

Robert

Apophis

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Re: Ascom Guidance?
« Reply #2 on: Jul 18, 2017, 10:25:41 »
With Pulse guiding your using both Axis. Much more accurate and what you want to be using with a GEM style mount.
The ST4 cable is not plugged in?
Roger
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NoelC

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Re: Ascom Guidance?
« Reply #3 on: Jul 18, 2017, 11:34:49 »
Robert - Thanks will PM you.
Apophis; agreed, with all the overwhelming arguments in it's favour I pitched my shoestring astronomy box and 'Star2000' guiding setup into the bin upgrading to an Atik camera with OAG and GP guidecam (which will only use ASCOM).

Since when; I have not been able to get the mount guiding cleanly (and consequently done little but spend money on replacing bits).  The guiding looks like its being affected by massive backlash and is occasionally almost usable.  But three out of four calibrations are useless.  Only last session did I try manually guiding, and realised there was something very wrong.
In manual, it guides a few steps in either RA or Dec (ISGUIDING=TRUE), then when you switch axis it stops working (ISGUIDING=FALSE) occasionally coming back again after several attempts.  Only did it for 2 mins, but it seems to be 100% if false - no movement.
Synta mount, a bunch of telescopes and a shed (on wheels).

RobertM

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Re: Ascom Guidance?
« Reply #4 on: Jul 18, 2017, 13:17:52 »
Robert - Thanks will PM you.
Apophis; agreed, with all the overwhelming arguments in it's favour I pitched my shoestring astronomy box and 'Star2000' guiding setup into the bin upgrading to an Atik camera with OAG and GP guidecam (which will only use ASCOM).

Since when; I have not been able to get the mount guiding cleanly (and consequently done little but spend money on replacing bits).  The guiding looks like its being affected by massive backlash and is occasionally almost usable.  But three out of four calibrations are useless.  Only last session did I try manually guiding, and realised there was something very wrong.
In manual, it guides a few steps in either RA or Dec (ISGUIDING=TRUE), then when you switch axis it stops working (ISGUIDING=FALSE) occasionally coming back again after several attempts.  Only did it for 2 mins, but it seems to be 100% if false - no movement.

Based on that I think it shouldn't be too hard to resolve or at least pinpoint your issues.

The Thing

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Re: Ascom Guidance?
« Reply #5 on: Jul 19, 2017, 09:58:47 »
Hi Noel,

I have an HEQ5 and when I first got it third or more hand from Robert it had a lot of mechanical issues, it's now had new bearing and belt drive and purrs like a kitten. And electrical issues,  I had problems as in some orientations the power connection became 'uncertain' and caused momentary dropouts, but not enough to disconnect the comms. The power connector is feeble and I have replaced it with an aircraft style connector after doing some research on line.

What software are you using for guiding? Make sure you have the latest ASCOM Platform installed and EQASCOM from the Yahoo group Files section not Sourceforge as they are quite old versions on there and they are always improving things. I'm using 2.00j. Have you used the Toolbox-Driver Setup to change from ST4 to PulseGuiding? 

I assume you are using PHD2. I use the development builds from openphdguiding.org as again they are always improving things (never had an issue with their development snapshots). Did you use the New Equipment Wizard to set up your new camera and guidescope combination? If not do it as it asks the right questions. You run it with only the guidecam connected to the laptop. Build a dark library and bad pixelmap, they become part of the equipment profile.

Then next time you have a chance to see a star in the sky (a few clouds don't matter), set up, calibrate (necessary) and use the PHD2 Tools/Guiding Assistant, it will help identify issues, suggest guiding settings for your new setup and do a backlash measurement. Also you can do a Star Cross test which will show up inequalities in mount movement very effectively.

Also take it to the experts at Roberts imaging session, I  won't be there as it's a bit of a long drive from Manche, Fr. ;)

Hope that helps, you probably know most of it already. Good luck and persevere!

Duncan
Life is like a box of chocolates, scoff it while it's in front of you.

NoelC

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Re: Ascom Guidance?
« Reply #6 on: Jul 21, 2017, 17:55:34 »
Thanks Duncan
I stayed up last night once it cleared to run the mount using ST4 using another camera (QHY5-II).
The mount seemed to respond correctly; and calibrate fairly cleanly.  However the tracking was not much better.
The Guiding Assistant still diagnosed massive Declination backlash (2450ms) and large polar alignment error  (which doesn't seem right) but the Dec guiding came in under 1".  However... the RA guiding was then all over the show (+-3").

Am going to Robert's imaging session so hope to get more understanding there.

Noel
Synta mount, a bunch of telescopes and a shed (on wheels).

Apophis

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Re: Ascom Guidance?
« Reply #7 on: Jul 21, 2017, 20:04:59 »
I used Eqmod pulseguiding at cairds for the first time last night , I posted the result M16 Eagle Nebula in Astrophotograpy section.
It seemed to go fine.
roger
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NoelC

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Re: Ascom Guidance?
« Reply #8 on: Jul 22, 2017, 11:02:43 »
Very nice Roger (I can see the Eagle).
Robert; thank you very much for hosting your excellent imaging workshop and for your in-depth insight.  I've got quite a lot to think about. Here's some of the points..

On the mount; your observations on the RA friction needs to be investigated (lateral force on main RA bearing and worm bearings - RA bearing too tight, worm bearings too loose).  Also RA backlash to be investigated.  From your observations DEC looked fine (contrary to what PHD Guiding Assistant is reporting).

Reviewing PHD Calibration charts- ASCOM pulse guiding clearly not working and giving very very weird results,
ST4 guiding working OK.

From reviewing PHD log data; tracking using ST4 is acceptable - I may have been over ambitious trying to image at f8 with un-tuned setup.  My maincam pixels are 4.54μm which is 0.6"/pix @f8.  Will try ST4 guiding at f6 (0.8"/pix) and bin main and guide cam given that seeing is unlikely to be better than 1-2" and binning the guidecam will give better star data for PHD to guide on.  Will also reduce the MinMo threshold to 0.2 or 0.3 (as opposed to 0.5).  Need to find some way of fitting the QHY camera to the Atik OAG.

Thanks again for your time and expertise.
Noel
Synta mount, a bunch of telescopes and a shed (on wheels).