Jump to content

1912116577_Solarchallenge2022banner.jpg.913a200cf105ddeae9f37765cb1d0c73.jpg

Autofocusing an old TAL reflector?


abmwinnoch
 Share

Recommended Posts

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 ?

2022-02-17 12.08.11.JPG

Link to comment
Share on other sites

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?

Link to comment
Share on other sites

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.

Link to comment
Share on other sites

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.

Link to comment
Share on other sites

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.

 

IMG_20220217_183403_2.jpg

Link to comment
Share on other sites

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.

 

IMG_20220217_183403_2.jpg

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.

EE2811CB-AEBC-4C08-84D7-B9D3AB012CCB.jpeg

48D6D083-B8E5-4147-BCFD-A804F512D615.jpeg

Link to comment
Share on other sites

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

 

Momentary Push Button Switch OFF-ON.png

Link to comment
Share on other sites

  • 2 weeks later...
  • 1 month later...

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.

1232.jpg

1231.jpg

1233.jpg

  • Like 1
Link to comment
Share on other sites

Create an account or sign in to comment

You need to be a member in order to leave a comment

Create an account

Sign up for a new account in our community. It's easy!

Register a new account

Sign in

Already have an account? Sign in here.

Sign In Now
 Share

×
×
  • Create New...

Important Information

We have placed cookies on your device to help make this website better. You can adjust your cookie settings, otherwise we'll assume you're okay to continue. By using this site, you agree to our Terms of Use.