I designed this for my Vixen Telecope as I wanted a perfect fit solar filter with no vignette.
Once printed you simply cut out a square of solar film and sandwhich between the front plate and the body. There are 4mm holes for bolts but I suggest using M3 bolts with washers so that the film doesnt get rippled too much
I also suggest printing the front plate with an increased z size to make it thicker.
The casings fit on the front and back to keep your film protected and dust free. Suggest using an elastic band to hold them in place.
I hope this comes in handy to someone, its free for non-comercial use but if you feel you would like to make a small donation this would be much appreciated and helps fund my hobby.