Quote:
Originally Posted by Joshua Bunn
Hello Josh,
I like your thoughts here, I recon it would work well, just need a few dowel pins to keep the orange and green parts orientated. There is one thing i would try and change though... the dovetail need some clearance to rotate (if it has no locking ring), and unfortunately clearance mean free-play and movement, possibly introducing tilt. did you have a solution to this?
I have a different design (to yours and Stefans) that I am working on now, Ill see how that goes.
regards Josh  |
Thats good to know i'm on the right track. i was thinking of making the blue piece a split ring, with the split cut on a fairly steep angle to stop light leak.
EDIT: On second thought, maybe trying some kind of wedge system instead?, maybe the silver piece could thread in to wedge and lock the dovetail piece in place? being a wedge design it would self-centre as well. that way you can lock it in place as well without having to worry about light leaks. Personally I would still forego the dowel pin in favour of being able to use it as a rotator. Maybe have a secondary lock between the blue and green pieces to preserve your spacing?
Another idea is to use a tried and true Turn-bucklet style LH and RH thread combo something like the attached. I've used a very coarse 2mm pitch for the extension thread, for every full 360deg of the centre piece you gain 4mm overall of extension. you could put a pin from each of the recievers that will stop on a centre obstruction to prevent completely unthreading and limit the overall in/out travel. still not sure how tightening this would work with regards to light leaks. Again, index marking the central piece could translate to pretty precise extension values (1mm/90deg turned, mark at 9deg increment for 0.1mm of extension.