Autofocusing an old TAL reflector?

[abmwinnoch]

Hi- due to a (very) extended wait for my new OTA I have been using my old TAL optics for use with my ASI294MCpro on an EQ6-R mount. With NINA / sharpcap I can run sequences and automate most aspects of imaging, bringing this 'made from Russian tanks' 1990's relic kicking and screaming into the modern astrophotographical age ! One thing I haven't tried doing with it yet is attaching an electronic focuser to it. I think the focus knob comes off, or at least turns to adjust resistance- not tried this but I'm sure I've seen this on a youtube vid. Anyway has anyone on here ever tried to remotely focus a TAL ?

[banjaxed]

Those focuser knob grooves look like they would take the GT2 timing belt if you could find a way to attach the motor.

[abmwinnoch]

2 minutes ago, banjaxed said:

Those focuser knob grooves look like they would take the GT2 timing belt if you could find a way to attach the motor.

Can you elaborate please- what is the GT2?

[banjaxed]

9 minutes ago, abmwinnoch said:

Can you elaborate please- what is the GT2?

I am adding a pic of one of my diy focusers so you will see what I mean.

[abmwinnoch]

Interesting! How do I go about getting/building one of those?

[Peter-uk]

I have one of these motors and was thinking of using it for the same thing, but at 10rpm i thought it would be a little slow how do you find it?

[banjaxed]

16 minutes ago, abmwinnoch said:

Interesting! How do I go about getting/building one of those?

 

17 minutes ago, abmwinnoch said:

Interesting! How do I go about getting/building one of those?

If you are interested I can give you my contacts for motors and fixings.

[banjaxed]

15 minutes ago, Peter-uk said:

I have one of these motors and was thinking of using it for the same thing, but at 10rpm i thought it would be a little slow how do you find it?

The reason I built my own focuser motor unit was the Skywatcher one is extremely slow especially when using on a Mak. I use a 30 or 40 rpm motor with a forward/reverse + speed controller, all of which cost less than the Skywatcher motor focuser kit. I can give you details if you would like me to. I think your 10 rpm might be a bit slow but it depends on the maximum voltage it will take.

[Peter-uk]

Yes, I think I might have to look for another motor as the two I have at the moment, one is only 10 rpm but the other one

is 3000 rpm.  As I have a speed controller forward and reverse which I could use on this.  I think this motor is a bit heavy.

I have ordered some momentary switch buttons which I think will help me.

This is what I was playing with in the garage moments before I saw your last thread.

 

[banjaxed]

14 hours ago, Peter-uk said:

Yes, I think I might have to look for another motor as the two I have at the moment, one is only 10 rpm but the other one

is 3000 rpm.  As I have a speed controller forward and reverse which I could use on this.  I think this motor is a bit heavy.

I have ordered some momentary switch buttons which I think will help me.

This is what I was playing with in the garage moments before I saw your last thread.

 

You can get good reversible motors from Amazon and eBay for around £10.00 plus fixing bracket if you need one. Your controller is exactly the same as the ones I use but mine are mounted in a plastic box, see below.

[Peter-uk]

Yep Just ordered a 60rpm one from ebay, the fixing bracket and control box i think i'll do on the 3D printer to start with

If it works out well i can machine them all out of aluminium

Here is a pic of the buttons I ordered so I can have them work like a jog control

 

[banjaxed]

I have not used a 60 rpm motor yet but you can always reduce the voltage if you find it too fast. Looking forward to see how your project turns out.

[CCD-Freak]

Just thought I would throw out another idea for mounting the motor via a finder mount shoe.

 

 

[Peter-uk]

I have got around to finishing this project at last.  I changed the motor out for a much slower 10rpm.  Included the dew heater into the support ring for the

auto focuser.  Got rid of all the switches and are using the remote control (white box in image is the receiver and the tab in front of it is the transmittor) 

I know this works up to about 10 meters.  As it is remote control I added a clutch in so that I do not break anything when I over run the focuser.

Also hoping to use the same ring to support a dew shield, but that is another project.  Just added the post for the time being.

[Starman18]

Nice ideas. Thanks! Will try as a later project.