How do I properly set the rotation speed for my CPA-2 or CPP-2 processor?
For many years, JOBO has recommended rotation speed settings of 4 for use with our 3000 series drums and P for all other tanks and drums, to properly set the rotation speed. Now there are two different sets of speeds which need to be listed based on the type of motor in use in the processor. The following processors need to follow the new speed settings.
- All CPA/CPP processors with serial numbers greater than 22000.
- All CPA/CPP processors that have been upgraded with the new rotation motors (93026).
Both of these categories can most easily be identified by the screw head in the center of the cog on the rotation motor shaft. If there is a hex-socket screw (it uses an Allen key to turn the screw in installation) then it is the new style motor.
All older motors, using a slotted screw in the center of the cog on the motor shaft, still use the old speed settings shown below, and as listed in the instruction manuals that accompanied them.
Old Settings
0 - Off
F - 25 r.p.m.
3 - 40 r.p.m.
4 - 50 r.p.m.
P - 75 r.p.m.
6 - 78 r.p.m.
7 - 80 r.p.m.
*New Settings
0+ 25 r.p.m.
F - 46 r.p.m.
3 - 70 r.p.m.
4 - 86 r.p.m.
P - 86 r.p.m.
6 - 86 r.p.m.
7 - 86 r.p.m.
*These speeds are approximate and variations of 10-15 r.p.m. will not show up in your processing results
If you want to determine the proper speed settings for your processor, put a drum on the processor filled with an appropriate amount of water to simulate normal processing loads. Then swing the three-fingered switch out of the way, so the drum will only rotate in one direction, and then begin timing and counting the rotations of the drum. (Only use the single direction rotation for determining the correct speed dial settings. Always use bi-directional rotation when processing film or paper.)
