Mamiya 48mm f1.5 helicoid adapter for mirrorless camera

thingiverse

The Mamiya 48mm f1.5 lens is found on a Mamiya Deluxe rangefinder. This is a fixed lens camera - and removing the lens will break the camera so should only be done on a broken model. This is probably not a good first project for those adapting glass from fixed lens cameras and you should practice on more common and cheaper models to practice on ways of removing lenses. The Mamiya is straightforward to work on. Once the lens is free from the body the camera shutter blades either need to be removed or fixed open. These are between the front and rear elements of the lens. Again practice on other lenses first. There are three STL files in this thing. The key one is the adapter. To mount this on the lens you need to remove the rear part of the lens (as shown in the photo). The adapter has two grooves that fit over the two small pillars that screw into the lens housing. The adapter is then held tightly against the lens housing when you replace the rear lens element. It should screw all the way back in. The adapter can then screw into a 17-31mm M42 helicoid which can mount to a mirrorless camera via a slim m42 adapter. I developed this for Sony E but as it focuses a little beyond infinity it should work with any mirrorless camera as their flange distances are all quite close. As the adapter has an M42 screw you need to print this at high quality. Also provided is a hood that can push fit on the front of the lens facing either forwards or backwards for storage. The cap push fits over the adapter when facing backwards. The cap is very slightly elliptical and you should squeeze the marks on the cap to put it on. The hood is entirely optional and you may need to do some filing to be able to put it on the lens. The hood and cap can be printed at a lower quality.