When DIY focuser ends up being as big as the optics ;)

[kbrown]

It looks a bit ridiculous but does the job well. The one thing that has put me off from doing more wide field imaging with my lenses is the lack focus control. It's quite fiddly to do manually with some lenses. Can't wait to test this out

[JeremyS]

Now that looks serious! 

[tomato]

Very nice! How is the toothed ring fixed to the lens body, just a tight fit or by some other means?

[kbrown]

5 minutes ago, tomato said:

Very nice! How is the toothed ring fixed to the lens body, just a tight fit or by some other means?

I tried to get it stay on just as a tight push fit but it just kept popping off as the edge of the focuser ring is beveled and there's not much to grab onto. Thought of double sided tape but I don't think that would have worked very well. In the end I just glued it on with four drops of superglue.

[Astronomist]

nice work!  where did you get the motor/gearbox assembly or is that 3D printed also?  

[bottletopburly]

On 09/11/2022 at 17:35, kbrown said:

kept popping off as the edge of the focuser ring is beveled and there's not much to grab onto

I just ordered a shapeways follow focus adapter as I couldn’t find a suitable adapter on thingyverse or anyother 3D site ,that one clips on to the shallow recess on the nifty fifty that’s set back 6mm from front of lens 

http://www.shapeways.com/product/9ZMKHDM3G/nifty-fifty-canon-50mm-f1-8-follow-focus-adapter

[kbrown]

On 13/11/2022 at 14:20, Astronomist said:

nice work!  where did you get the motor/gearbox assembly or is that 3D printed also?  

The focuser itself is my BullsEye Focuser I posted a while back: http://knowhere.myqnapcloud.com/WordPress/2021/09/04/bullseye-diy-focuser/

For this I used a small 6Nm NEMA 11 stepper motor.

Gears and the bracket are all 3D printed also. All designed in FreeCAD.

Edited November 16, 2022 by kbrown