Please help with my Synguider

[nebulosity. (Jo)]

G'day

I'm having no end of troubles with my Synguider and I hope Someone can help me. I am imaging with a 1200mm fl newt on an iOptron ieq45 and an 80mm f5 guide scope. The main drama I'm having is with the guide star driving of the screen, I get the guide star focused, centred, do an auto calibration and as soon as it stars guiding, the star will drive of the screen in either Ra or Dec (and some times at an angle) what is coursing this?

The mount is well polar aligned, up to 1 minute or more exposures possible with good stars.

The Ra/Dec axis of the guider is precisely aligned with the Ra/Dec axis of the mount, (I find the more precisely this is aligned the longer the guide star will star centred (up to 5 min) before moving off the screen.

The star generally takes around 20 seconds, once it stars moving to be fully off the screen.

The star does not drift off, it is driven off, without guiding going it will stay centred for ages.

The guide speed on the mount it set at 0.25x, I have tried all different speeds up to 1.0x with no benefit

On the mount I have set the guide port to reverse and normal with no difference.

I have played around with the guiding aggressiveness and have it set on around 300.

I've spent over 20 hours trying to get it working and still haven't got a single proper guided sub, I'm running out of ideas so would appreciate any help.

Cheers
Jo

[midnight (Darrin)]

Hello Jo,

I have a NexGuide which is a rebadged Synguide so they should be the same.

The only thing I can suggest is to watch if you can, the mount's present RA & Dec during the calibration. I do this on my G11 by watching the hand controller's ra,dec position so I know it is driving the correct motor.

If the mount is indeed responding to the guider (and it sounds as if it is) then possibly the ra/dec corrections are somehow reversed? I don't know but check the synguide and your mount during the calibration to make sure it is correctly performing this critical routine. It's good to see you're making use of the aggressiveness as I find it makes a noticeable difference.

Unfortunately, I'm on remote assignment with my gear in storage so can't really help much more.

Good luck,
Darrin...

[nebulosity. (Jo)]

Originally Posted by midnight

Hello Jo,

I have a NexGuide which is a rebadged Synguide so they should be the same.

The only thing I can suggest is to watch if you can, the mount's present RA & Dec during the calibration. I do this on my G11 by watching the hand controller's ra,dec position so I know it is driving the correct motor.

If the mount is indeed responding to the guider (and it sounds as if it is) then possibly the ra/dec corrections are somehow reversed? I don't know but check the synguide and your mount during the calibration to make sure it is correctly performing this critical routine. It's good to see you're making use of the aggressiveness as I find it makes a noticeable difference.

Unfortunately, I'm on remote assignment with my gear in storage so can't really help much more.

Good luck,
Darrin...

Thanks a lot for your help Darren

The guider does move the mount during calibration, not much though, maybe one or two arc min?

I'll double check to make sure the the signal is right, in the mount settings I can reverse it, which I have tried, I guess I'll try again

Cheers
Jo

[Tony_ (Tony)]

I also have a nexguide - it keeps the guide star centered for hours, problem I have is with flexure.
If it's guiding for 5 minutes then it must be working (at least to some extent). When it starts to drift - does it drift in any particular direction? eg. in the RA direction.
Also if the auto cal is working it will automatically choose the correct signal direction. If it is a standard set-up problem it should occur as soon as you start guiding?
I don't know anything about your mount but if it has backlash compensation or PEC apparently during guiding it is best to have these off.
Unfortunately there are probably a lot of possibilities. You will just need to eliminate them. I doubt whether it is the aggressiveness or guide speed.

Good Luck,
Tony.

[midnight (Darrin)]

Originally Posted by nebulosity.

The guider does move the mount during calibration, not much though, maybe one or two arc min?

Yes this is correct. Mine only moves about 1 to 2 arc minutes during calibration in each direction.

Originally Posted by Tony_

Also if the auto cal is working it will automatically choose the correct signal direction

Agreed. It will ( one hopes!) Work out direction and compensate for any guide camera orientation.

I can really only think that somehow the correction signal from the guider is reversed during guiding. It seems to be the only logical explanation without knowing more about your mount. So explore that Jo & try eliminating each possible cause one by one. I hope you get there as the guider does a good job without the need for a computer.

Cheers,
Darrin...