Mamiya TLR Rear Lens Caps
3D Printed from a design by Tomáš Hájek from Thingiverse.com
There are two sizes of rear lens caps for the Mamiya TLR. Which one you need depends on the size of the rear element. Generally, lenses with a 49mm front filter size will need the larger size rear cap, while the others will need the smaller size.
I used Hatchbox TPU filament on my QIDI X-Plus to produce the caps pictured. The choice of green filament was governed by what I had available. It might be a bad choice if you work over grass a lot, however it made the illustrations clearer! TPU can be a challenge to print, as it needs to be dried and kept desiccated. The feed in the printer has to be smooth, as this filament will stretch. The print speed should not be too high, as this and too low a temperature can prevent layers from bonding. It also helps a lot to have a direct drive extruder and to ensure that you do not over drive the filament, otherwise it will kink and stop extruding.
The Caps in use
These are slightly softer than the Mamiya originals, but the flexible material grips well. I had to clean up some stringing and bumps with a sharp knife, but nothing exceptional. The pictures show an 80mm lens pair with a small cap, the 180mm Super alongside the new cap and the original, and the 180mm Super with the new cap fitted.