Askar FMA135 Astrograph Front Thread Size

[Stratis]

Reaching out to people who own both an Askar FMA 135 astrograph and a thread gauge!

The FMA135 is a neat bit of kit, but I'd like to be able to attach something to the front threads, for example a 2" filter or a stack of M48 spacers to use as an extended lens hood. 

The lens cap threads directly onto the lens cell; is anyone able to determine what thread size that is so I can get an adapter made up?

 

All the best,

Paul

[nodeht14]

I also wanted to know this and after buying some adapters that did not work I trialled and errored some 3D printed threads.

I found that M36x0.75 with some tolerance adjustments worked okay for the printed threads, so that might be a good place to start if trying to buy/engineer a metal adapter.