Helical focusers for Telescope making workshop

[Anil (Anil)]

Hi all, i have designed these helical focusers for Telescope making workshop for ABAA (Association of Bangalore Amateur Astronomers.) This is a much better option over conventional cheap plastic focusers.

It has been designed from solid aluminium bars This design offers a fast & smooth helical movement, no slop, and backlash free performance, with 2 inch travel. Focusers are machined to very precise tolerances which is necessary to provide accurate alignment, each weighs around 550 grams.

[mental4astro (Alexander)]

Hi Anil,

Very nice looking collection of shiny new focusers! They certainly look robust. Any commercial outlook?

Are you maybe considering a 2" version?

How long is the draw-tube travel? Is the draw-tube longer than the focuser housing? This makes the travel capacity longer and more flexible for a range of applications.

I have one suggestion: maybe on the mounting surface of the focuser, either mill out a curved surface for better mounting to the scope, or mill out little 'legs'. These will allow for a more positive coupling to a round reflector tube. It may also help to further reduce weight, and doesn't compromise strength.

[Anil (Anil)]

Thanks for the comment, yes i am thinking of marketing it here in India. Here a branded creyford focuser costs $150 but my helical is a better alternative to cheap plastic Rack & Pinion focuser. i certainly look in to 2" version on my next project with long sliding draw tube. The present version has 3" drawtube with 2 " travel. I shall also consider your advice on milling out a curved surface for better tube contact & final product will be black anodized.


Regards,
Anil

Originally Posted by mental4astro

Hi Anil,

Very nice looking collection of shiny new focusers! They certainly look robust. Any commercial outlook?

Are you maybe considering a 2" version?

How long is the draw-tube travel? Is the draw-tube longer than the focuser housing? This makes the travel capacity longer and more flexible for a range of applications.

I have one suggestion: maybe on the mounting surface of the focuser, either mill out a curved surface for better mounting to the scope, or mill out little 'legs'. These will allow for a more positive coupling to a round reflector tube. It may also help to further reduce weight, and doesn't compromise strength.

[mental4astro (Alexander)]

Just one note on the 2" version, stick with the helical design, not sliding.

I did not mean to confuse you. I really like helical focusers! I've used both 1.25" and a 2" version on a scope I've made.

[Anil (Anil)]

2" version will be helical with long draw tube with 1.25 adapter. I shall share the picture soon.


Regards,
Anil

Originally Posted by mental4astro

Just one note on the 2" version, stick with the helical design, not sliding.

I did not mean to confuse you. I really like helical focusers! I've used both 1.25" and a 2" version on a scope I've made.