January 25, 2024
Description
These lens boards are designed to fit the MPP Micro-Technical Mk. VII (Mk. 7) and are based on an original MPP #1 board as a reference. Not sure about the lens board dimensions of earlier models, but I'm pretty sure the Mk. VI (6) has the same fitting. They definitely will not fit the Mk. VIII (8).
The lens hole diameter on these boards is 0.2mm larger than lens spec, as I decided it was better to have the possibility of a tiny bit of play during fitting than having to cut away material. Also the retaining ring groove is 0.4mm larger than spec as some rings I have tried were still a bit tight.
These have stood up very well so far, but I disclaim any responsibility for lenses dropping off cameras. If it's very loose or you doubt that it will hold the weight of a certain lens, then exercise great caution.
These models are intended to print best at 0.2mm layer height for dimensional accuracy.
I haven't used these with heavy lenses, but going with at least three perimeters and 25% infill will be on the safe side strength-wise.
Tested so far with PLA, ABS and ASA. PLA works well for its stiffness, but obviously not for heat resistance. ABS and ASA are very good choices. Not tested with PETG, but it should be fine - maybe try 100% infill for extra stiffness.
Filaments with a more matte finish may reduce internal reflections, but I haven't noticed a difference yet.
If the board comes off the printer with a little corner lift or uniform warp, it shouldn't be an big deal. But if the warp is irregular it could possibly cause lens tilt and field-of-focus problems.
Coloured fronts can work nicely with these if the first few (front-facing) layers of the print are a colour and the rest is changed for black. The numbered boards (0.6mm embossed text) work best if the change is on the layer where the number is bridged over, so it shows with good contrast. A three-colour print also works well if the bridging layer (+1 more) is the second colour, then black for the rest.
These all print face-down, except for the cone board, which needs printing face-up with supports. This board is also not suitable for layer-change colour printing unless a bit of the inside is painted black afterwards.
The font used for the numbered boards is D-DIN Condensed Bold (SIL Open Font License v1.10.) The whole font family can be found at https://www.fontsquirrel.com/fonts/d-din
A good resource for looking up Compur shutter specs: https://web.archive.org/web/20230521200841/https://skgrimes.com/products/shutters/compur-shutters
A board for the Mk. VIII (Mk. 8) can be found at: https://www.thingiverse.com/thing:282044
License:
Creative Commons — Attribution
Geoff
