RB67 140mm Macro C: Collided Blades in the 870 Shutter
Originally posted on Instagram. Notes from the repair bench, kept here as a searchable archive. View the original on Instagram
Servicing a Mamiya 140mm f/4.5 Macro C lens for RB67. The problem with this lens was that the shutter blades collided and are ruined. The second photo shows the shutter out of the lens and the third photo shows a close up of the damaged shutter blade tips. This lens, from 1981, has the early style of the new 870 shutter that has flat shutter blades. Mamiya later added a curved tip on the bottom and top blades to prevent this sort of thing from happening. The last photo shows the new style blades with curved upward tip.
In this case, the repair was straightforward, just had to replace the shutter blades. I always check the shutter mechanism plates for parallelism when I see damaged blades as I suspect impact damage to the shutter in cases like this.
