Suggestions for attaching a Bahtinov mask to a F/5.9 refractor

[choochoo_baloo]

I've been pondering how I'm going to attach this Bahtinov mask to my William Optics refractor. A brief internet search has failed to give a definitive answer (which surprised me). Therefore I'm inclined to go for a custom fitting, and would like advice on the below sketch.

The plastic cylinder will be made from Delrin (I have some lying in the workshop). It's a shame to have to cut three slots in my new shiny Bahtinov mask, but I'm really struggling to think of an alternative design.

Suggestions will be gratefully received.

 

[johninderby]

Simple as using two nylon bolts. Have a look at the way Starsharp masks are made.

http://www.morris-engraving.co.uk/bahtinov.htm

[Stub Mandrel]

As you never, ever, use a bahtinov mask with the tube pointing at anything other than an upwards angle, you just need two pegs (I was supplied a mask with two M6 nylon screws) to hook over the end of the dewshield/scope. I've used the same arrangement for home made masks, or for smaller ones I have 3D printed them with a semi-circular lip. Has the great advantage that you can place and remove them without disturbing anything.

[hughgilhespie]

8 hours ago, Stub Mandrel said:

As you never, ever, use a bahtinov mask with the tube pointing at anything other than an upwards angle, you just need two pegs (I was supplied a mask with two M6 nylon screws) to hook over the end of the dewshield/scope. I've used the same arrangement for home made masks, or for smaller ones I have 3D printed them with a semi-circular lip. Has the great advantage that you can place and remove them without disturbing anything.

But..........if it does fall off it will probably break!

[choochoo_baloo]

14 hours ago, johninderby said:

Simple as using two nylon bolts. Have a look at the way Starsharp masks are made.

http://www.morris-engraving.co.uk/bahtinov.htm

 

Is your mask tapped to take the bolts - the mask seems only a few mm thick? Otherwise a sliding fit would be pretty useless.

[lux eterna]

Maybe this can help.

Ragnar

[Stub Mandrel]

19 hours ago, choochoo_baloo said:

Is your mask tapped to take the bolts - the mask seems only a few mm thick? Otherwise a sliding fit would be pretty useless.

I have one like that, they are just a tight fit and haven't ever fallen out. I use the same principle with my larger 3D printed ones.