These drums are very conservative on chemicals. I'm using the little Jobo 4x5 test print drum to process 4x5 paper negatives and Harman DPP prints. Its label indicates "45ml capacity," but I've taken to using about 90ml of chemistry (85ml water + 6ml Ilford liquid paper developer concentrate), and I get good results. The reason I went with the higher capacity is because I was concerned about developer exhaustion at the 45ml volume, since I use about a 1+13 dilution, and the test print drum takes two sheets of paper at a time. Especially for Harman DPP, which needs a bit more developer action than paper negatives.
At around 100+ml of volume it will start to slosh out of the tank when on its side and being rotated, so I try to stay below that limit in volume. For your paper drum, figure out from experimentation how much liquid it takes before it sloshes out of the mouth when on its side, and stay at a reasonable volume below that.
I don't have a motorized base, nor the manually operated base with rollers - though I'm planning at some future date on making one - so you have to rotate the drum by hand. I've taken to using a paper towel in my left hand, upon which the main body of the drum rests, with the lid pointing toward the right, and I spin the bottle with my right hand. The friction between the paper towel and the plastic bottle makes it easy to spin with little friction.
For timing each step of the process, when you pour in the chemicals they sit in the central portion of the lid and don't contact the paper until you tip it on its side and begin rotation, at which time the liquid pours out of the apertures around the lid and onto the paper. A very efficient design, and I've seen no hints of irregular development, so its very uniform.
I"ve tried tray processing my Harman DPP prints using the same volume and dilution as I use in the print drum, and I can't get as good of results in trays without using much more volume of chemistry. So the drum does a good job.
Your process looks okay, I'd recommend a holding bath of rinse aid after the fix and preliminary wash, this will permit you to do your quick 3x30 final rinse and help get a better rinse. Just a few minutes time in the rinse aid bath should do it.
I use a water rinse between developer and stop bath and stop bath and fixer, just to extend the life of the stop and fix. I use little cups marked to the 85ml level. This process is very economical on developer (6ml of concentrate per two 4x5 prints) that I use the developer one-shot. Especially important for Harman DPP, but paper negatives can get by with used developer - provided you can develop by inspection, which rules out the tank method.
For drying RC prints I squeegee both sides, then use a hair dryer on high to dry them immediately. I hold the paper curved in one hand and operate the dryer in the other. The trick is for the print not to fly out of your hand and land (of course) front side down on the dirty floor. Then immediately after drying I place in plastic protector sleeves. Guarantees minimal dust gets on the negatives.
(EDIT: I have a dedicated hair dryer for print drying. You don't want to see how dirty a used hair dryer can make a paper negative!)
~Joe
