RB67 Power Backs: Motorized Back Versions Explained
Originally posted on Instagram. Notes from the repair bench, kept here as a searchable archive. View the original on Instagram
I get a regular stream of questions regarding the motorized backs for the RB67. So, here is the breakdown:
Mamiya initially introduced the 120/220 power back for the RB67 in the version shown on the left in the first photo. It was a reworked PRO-S back with a motor added in the bottom and also a different pressure plate scheme. The back used interchangeable pressure plates for 120 or 220 film. And, not shown in the photo was a separate battery pack/control unit that fit under the camera. It was a bit clumsy and heavy and not a real popular accessory. These days you often encounter these back as shown in the photo without the power pack as it is still usable manually with a lever wind (although it is heavy since it has the motor in the extended bottom plate)
The back on the right is the power drive back that was introduced with the RB67 PRO- SD. This particular example is the 6x8 version ( I also get asked a lot about fitting 6x8 to the RB67 PRO-S and this is possible but you need to have the Mamiya supplied 6x8 rear frame installed on the body and also the PRO-SD revolving adapter). It has a self contained battery holder in the center of the back door and total weight is a little over a pound, which is about half the weight of the original power drive back and battery pack. This was also available in a 6x7 version and these versions are usable manually without motor drive support.
The last two photos show why I have been thinking about these backs as a repair this week was to replace a broken battery compartment lock on the 6x8 back. Yes, plastics deteriorating with age.
