Just as an update, I mocked up an extremely rough spider vane from photos and knowledge that the ring is about 200mm in diameter.
2mm vanes (I do not know what the tolerance is here, and whether they could / should go thinner). I did 5mm radius' between the vanes and the secondary holder and outer ring.
Quotes in 7075 Aluminium with a glass-blast finish were coming in between £100 to £260 depending on supplier, which all in all, is pretty **** good. Discounts for multiples available also.
I've just made the vanes totally rectangular, not seeing any need to complicate them (some vanes I have seen are nearly diamond shape in side on view, which I do not understand).
If anyone has any feedback on design tolerances (I am absolutely not an engineer) I would appreciate it. Before I pull my beautifully collimated scope apart to take real measurements, I'd like to get this base mockup correct.
Thanks again for all the help.
Edited by mrflib, 05 October 2024 - 11:38 AM.