Autoguiding Problems

[Hagar]

HELP, HELP, HELP

I have an EQ6 Goto mount with an ED80 as an imaging scope and a WO 66 as a guide scope fitted with a meade DSI.
My attempts at auto guiding have been less than impressive using both PHD and guidestar through a GUSB adapter. The results I am getting are little if any better than the EQ6 can deliver without the guiding. Can anyone give me the settings for guide speed etc for either of these programs.

My mount is permanently set up on a pier and is pretty well polar aligned. I must be doing something wrong or have a setting wrong somewhere. Adjustment pulses are getting to and adjusting the mount.

Please Help
Doug:shrug:

[iceman]

Hi Doug

I have an EQ6 and use a 80mm f/5 refractor for guiding, with my DMK21AF04. I use PHD Guiding with the GPUSB to connect to the mount.

I used it for the first time the other night, and didn't have any problems at all - it stuck on the star the whole time.

What exactly is the problem? Is it not sticking on the star? What's the exposure time the DSI is using?

I didn't set any settings in PHD - just let it auto-calibrate and it was fine on the settings it chose.

[DeanoNZL]

Hi Doug,
I use PHD as well, and the settings will have to be adjusted for a small scope.
See attached pic for my settings when using a W/O 66mm
Using 1.5 sec exposure.
Also, it may be advisable to change the hand controller guiding rate to 1.0
See if you can isolate the problem, as Iceman says.:thumbsup:
Hope this helps

[Alchemy]

try as previously suggested a 1x guide rate, this will be set through your hand controller, that rate is 15 arc secs per second.
When you auto calibrate does the star go through its routine then lines turn green, and if you watch while guiding does the program seem to over correct, (the star bounces back and forth... this could suggest to fast a guide rate,) i find if possible for me that a one second interval works well

[Hagar]

I have gone through the setup proceedure , the lines turn green and all seems well except the finished photos show quite a bit of star trailing and if watched closely thestar used for guiding seems to bounce around a lot..
If the clouds allow I will try again tonight using some of the above ideas.
Thanks again.. It's great to have this site where you can often fix problems without too much hair loss....(I don't have much left( or right ))

thanks
Doug

[wysiwyg]

Doug,

If you are using PHD the orientation of the camera is taken care of by the calibration. I on the other hand cannot get PHD to calibate correctly, it keeps telling me that there is not enough movement in the star or RA axis, go figure.

I use guidedog (free download) to guide, the only thing is you have to align the camera to match N E S W with your hand controller, it takes few adjustments but works fine.

Guidedog is GPUSB compatible also, I use it as well.

I usually allow between 1 and 3 seconds exposure.

[Dennis]

Hmm, this is quite puzzling as the imaging ‘scope and guide scope have relatively short focal lengths (WO 66 = 400mm?) and I would not expect to see too much guide star movement if every thing is clamped down securely. Even with poor seeing (3 or 4 arc secs) I would not expect to see a star grossly bouncing around?

If the guide star is bouncing around a lot, then I would investigate how firmly the guide scope is attached to the mounting plate, how firmly the DSI is attached to the guide scope (grub screw), is the screw in adapter unscrewing (cable drag?), have you locked the focus knob to prevent the focuser from slipping, etc.

You can have problems if there is flexure between the guide scope and the imaging ‘scope. So, if the guide scope/auto guider tracks the guide star reasonably faithfully but the imaging scope/camera moves slightly relative to the guiding system, you will get star trails and this would be worse at long focal lengths.

This flexure can be caused by inadequate mounting of guide scope or imaging scope, allowing one, the other or both to make small movements as the mount changes orientation. If the guide camera flexes in the eyepiece holder, it can slip or rotate as the cables drag on it and so you will be chasing this movement as well.

Similarly, if the imaging camera is not firmly attached to the focuser, it may suffer from micro movements e.g. cable drag may cause it to physically move.

Cheers

Dennis

[DeanoNZL]

Hi All,
Doug, have you flash upgraded to v 3.12 on the hand controller?
It would also pay to check the backlash settings for RA & DEC.
These may make it jump if set too high.

[Hagar]

Thanks all. With a little perseverence and a few DSI connection problems thanks to Vista, it works.

Realy makes a big difference. Now all I have to do is get some better way to focus and I will be up there with the best.(Joke)ha ha.
Again many thanks

Doug