Guidescope Issue

[smudgeball]

Hi all

Wasn't sure where to post this.

I recently moved away from Windows to Stellarmate on a raspberry Pi.

My really old QHY5 wasn't compatible so I purchased an Altair GPCam 130 mono.

All works fine in KSTARS/EKOS ( I use phd2 externally for guiding rather than the internal guider for EKOS)

It's all fine...except that in my previous setup I ran the QHY 5 with my WO 50mm guidescope, leaving my 102mm and 80mm scopes free.

Since moving to the altair guidecam, I can't achieve focus and the only way to guide is by using my 80mm scope.

That's a pain as I like having my dslr on there for widefield imaging.

I've tried every adapter/tube I have to get as much backfocus and everything inbetween, but can't achieve focus.

Have gone the other way all the way in, (even removed the locking ring)

No joy.

It's not as if I'm not up and running, I am as it works fine for guiding with the 80mm, but would love to be able to free up my 80mm and use the 50mm for guiding.

Does anyone have any successful experience with an Altair / WO 50mm guidescope ?

Thanks

 

Regards

 

Neil

[michael8554]

You can't just guess the spacers needed, you have to measure.

Measure 200mm back from the objective. 

Measure how far inside the camera the sensor is. 

With the focuser in midpoint of travel, mount the camera so that the sensor is at the 200mm point. 

Fine adjust focus with the focuser. 

Michael 

[smudgeball]

Thanks Michael

 

I will give the 200mm space a go.

 

Regards

 

Neil

[smudgeball]

On 17/10/2019 at 23:28, michael8554 said:

You can't just guess the spacers needed, you have to measure.

 

 

Finally got a break with weather tonight and tried the 200mm spacing tip.

It worked !!

The amount of travel between star in focus and out of focus is barely 5mm.

I would never have worked this out without this starting point.

Now able to guide with the little 50mm WO scope, freeing up my 80mm for widefield once more.

Many thanks to Michael for his input.

 

Neil