Guiding problem with Celestron Advanced GT and ASI174MM cam

olexandr.kovalyov

Hi All,

I try start deepsky imaging using guiding. I use the following equipment: mount Celestron Advanced GT, guiding camera ASI174MM connected with ST-4 cable to mount. I use PHD2 software.

With connection everything is fine, but when I select guiding star and then start the calibration I have a problem: I see on the display that star is moved in the same direction and almost with the same speed like mount is just turned off, so calibration is failed. When I turn off calibration this quick moving is stopped, and motors are moved as expected again. I don't know, maybe there is some problem with drivers, or something like that? I installed all the latest versions of ASI drivers.

Or there is some problem with options in PHD2? I tried all possible solutions and it didn't help.

Maybe someone had similar experience and can help with solution?

einari

When you are doing calibration the calibration star should move in west, east, south and north.

Before calibration you should put your guiding parameters, focal length and pixel size (brain icon), so the calibration takes suitable number of steps.

olexandr.kovalyov

einari wrote:
When you are doing calibration the calibration star should move in west, east, south and north.

Before calibration you should put your guiding parameters, focal length and pixel size (brain icon), so the calibration takes suitable number of steps.

I entered all the required parameters, but such problem happens all the time

einari

Sorry I don't understand your problem.

The star should move while doing calibration.

Does it move outside the field?

olexandr.kovalyov

einari wrote:
Sorry I don't understand your problem.

The star should move while doing calibration.

Does it move outside the field?

Star is moved during calibration, and than PHD2 shows that calibration finished, but star is still moving in the same direction as I mentioned before. In fact guiding does not make it's function.

einari

Okay now I get it.

Something might be wrong then.

Have you checked the cables and connections?

As an alternative you could try guiding via as common.

olexandr.kovalyov

einari wrote:
Okay now I get it.

Something might be wrong then.

Have you checked the cables and connections?

As an alternative you could try guiding via as common.

I've checked this with two different ST-4 cables, result was the same. I will also try simple autoguiding in FireCapture(just to make sure if it works well) and another ASI224MC camera.

olexandr.kovalyov

I tried different cable, different camera ASI224MC, and then the problem still exists... Really don't know what to do...

Support@ZWO

If you change the camera and change cable and the problem is still exeist. I think the problem will cause by your AVX mount.

There is two posibilities:

1. AVX mount Guide port is damaged, cannot realize the command from computer.

2. AVX mount RA worm and gear have a big gap. So when the guide camera send the command to let the mount move to east, the mount didn't finished the gap then the calibration is already fail.

I think the second posibility is more identical to your description.

If the worm and gear have a big gap, you need to use some tools to make it tight again.