Originally Posted by
Greg Blank
Bi directional rotation is required for paper processing and smaller film drums. For Expert drums it is not required, I've tested this myself in practice finding no difference in the results of developing sing PMK developer.
I asked the question of the CEO of Jobo USA when the product distribution was being turned over to Omega Satter. His statement was that no, the Expert drums were not required to use it or for that matter designed to require it.
After working on many many CPP2's over four years time, I am lead to believe that the bi directional motion weakens the motor circuit if one is using an Expert series drum, furthermore a overly filled Expert drum.
What I do find required is the need to periodically lift the drum and insure that the chemical and water goes behind the sheets to wash off the anti halation backing. So I raise my drum once per minute for this purpose and turn the motor off while the drum is up and on once its back down.
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