Guiding help

[Dave kay]

Hi folks,

So I’m looking for advice on guiding, as my guide system is not working properly. I have an eq3-2 mount with synscan goto. I have a guide scope attached to my zwo camera which I attach straight to the synscan auto guide port. The zwo is also attached to my computer and running with phd2.  This set up has worked fine in the past but isn’t playing ball at the moment. 
My mount doesn’t seem to step east when either guiding using phd2 or when I’m tracking without my guide scope. However, I can easily move the mount in all four directions manually using the synscan controller. I thought I might have a dodgy auto guide port connection, but buying a new cable has not solved this situation. 
If anyone could shed some light on this problem it would be greatly appreciated. 

Thanks in advance,

Dave. 
 

 

 

[Tommohawk]

On 16/12/2020 at 21:31, Dave kay said:

Hi folks,

So I’m looking for advice on guiding, as my guide system is not working properly. I have an eq3-2 mount with synscan goto. I have a guide scope attached to my zwo camera which I attach straight to the synscan auto guide port. The zwo is also attached to my computer and running with phd2.  This set up has worked fine in the past but isn’t playing ball at the moment. 
My mount doesn’t seem to step east when either guiding using phd2 or when I’m tracking without my guide scope. However, I can easily move the mount in all four directions manually using the synscan controller. I thought I might have a dodgy auto guide port connection, but buying a new cable has not solved this situation. 
If anyone could shed some light on this problem it would be greatly appreciated. 

Thanks in advance,

Dave. 
 

 

 

Normally when I guide with EQ3-2  I have the laptop controlling the mount using Stellarium via an FTDI cable, plugged into the Skywatcher goto unit.  The guidecamera plugs into the laptop and uses PHD to modify the tracking commands. The camera doesn't connect to the Skywatcher unit - only to the laptop.

I don't use the Skywatcher handset at all, though I recall there is a way of setting up using the handset. Is that what youre doing?

If your going to use a laptop, it's probably better to do it using 1st method.

 

Edited December 17, 2020 by Tommohawk

[Anthony1979]

1 hour ago, Tommohawk said:

Normally when I guide with EQ3-2  I have the laptop controlling the mount using Stellarium via an FTDI cable, plugged into the Skywatcher goto unit.  The guidecamera plugs into the laptop and uses PHD to modify the tracking commands. The camera doesn't connect to the Skywatcher unit - only to the laptop.

I don't use the Skywatcher handset at all, though I recall there is a way of setting up using the handset. Is that what youre doing?

If your going to use a laptop, it's probably better to do it using 1st method.

 

This is the exact way i do it with my eq5.... Easy and simple

[Budgie1]

2 hours ago, Tommohawk said:

I don't use the Skywatcher handset at all, though I recall there is a way of setting up using the handset. Is that what youre doing?

I also use the EQDIR cable on my EQ5, but when I started guiding I used the handset update cable connected to the laptop and plugged into the spare RJ11 socket under handset. You then go into the Utilities menu on the handset and set it to PC direct mode.  

This allows you to do away with the ST4 cable and have PHD2 send the commands direct to the mount. In PHD2 you have to set the mount to HEQ5 instead of "On Camera". 

[rickwayne]

Even if you prefer to stick with ST-4 for guiding, it's worth at least setting up a test with pulse guiding (as the others have recommended) to isolate the problem further.

What do you mean that it won't step east when you're tracking w/o your guide scope? What would ever issue a "step east" command? 

[Dave kay]

16 minutes ago, rickwayne said:

Even if you prefer to stick with ST-4 for guiding, it's worth at least setting up a test with pulse guiding (as the others have recommended) to isolate the problem further.

What do you mean that it won't step east when you're tracking w/o your guide scope? What would ever issue a "step east" command? 

My image always seems to drift right, with or without my guidecam. Im going to give my mount a good service tonight and follow the advice above and try to guide from my computer instead. 

[Dave kay]

Thanks for all the advice guys. I’ll try and guide straight from my computer instead. Let’s hope I have more success that way 🤞

[rickwayne]

1 minute ago, Dave kay said:

My image always seems to drift right, with or without my guidecam. Im going to give my mount a good service tonight and follow the advice above and try to guide from my computer instead. 

Is that direction aligned with either axis? If you're not guiding, the mount shouldn't be running the DEC motor at all, so consistent drift along the DEC axis just about has to be due to polar alignment. You can use PHD on stars on the celestial equator, one on the meridian and one near the horizon, and run the Guiding Assistant tool for a few minutes to check. That will quantitate things and give you a decent estimate of your polar alignment error.

If it's aligned with the RA axis...huh. Wrong tracking rate selected (e.g. lunar)? Do your PHD guide graphs show any particular pattern?

[Dave kay]

1 hour ago, rickwayne said:

Is that direction aligned with either axis? If you're not guiding, the mount shouldn't be running the DEC motor at all, so consistent drift along the DEC axis just about has to be due to polar alignment. You can use PHD on stars on the celestial equator, one on the meridian and one near the horizon, and run the Guiding Assistant tool for a few minutes to check. That will quantitate things and give you a decent estimate of your polar alignment error.

If it's aligned with the RA axis...huh. Wrong tracking rate selected (e.g. lunar)? Do your PHD guide graphs show any particular pattern?

I’m pretty sure it’s the RA blue line which just gradually wanders away from my target star. Sounds like I should take more care when setting my polar alignment. I’m going to try a few of the above ideas tomorrow and will feedback with a hopefully some success.