Using Unicolor Motorbase Developing Roll Film with Small Tank (Home made rotary tube processing)

I’ve decided to name this mo-chine, The Uni-Coffee Roller.


I purchased a bunch of darkroom items the other day, along with all the stuff is a beseler/unicolor motorized base, with a 5×7 and 8×10 paper drum. While I can use the paper drums to do sheet films, which I do not shoot, I wanted to rig something up so it will accept my small tank on top to develop my roll films. If anything it will be very good for fixing. So i devised this plan.

The motorbase. A metal coffee can with grooves, and my developing tank, and a piece of foam.
The roller will stays in the can’s natural groove, there for no need for elastic bands. But try it out yourself see whats the best way to make the can stays on top of the motor base.

Pointing out the obvious. Put the developing tank in there, and then I cut out a piece of foam so it will make the tank stays LEVELLY inside the can.
You must make the can fit as level as possible.

And there I have my own small tank rotary processing machine.


Before My test run, i figured 18oz will fill the tank up to the top, same amount for 120, for this particular tank, if you divide 18 by 2, that gives you 9, which should be half of the total volume inside the tank. But then, Instead of standing the tank straight up, its going to be used sideways, I added an extra 3 oz, just to cover to top part if the developer decided to go there. So i have 12 oz, which is actually what the tank calls for 135 normally. But I can use 12oz to develop 120 from now on also.  I also hooked up the motor base to a darkroom timer, so it will just stop and/or make a buzz when it’s done. I’ve developed 4 rolls of 135 (TMX and TRI X) using this thing-a-mc-git so far, it develops and fixes the negative evenly and flawlessly, and its essentially effortless. Even if you are critical about your development, like i said, you can still at least fix your film with this thing. It fixes the film CLEAR, without effort. For the time, Look it up in the film’s spec sheet for Rotary Tube Processing as a reference. Finally, I will give you a sample of what this machine can do.

Kuribayashi Petri 1.9 CCS, Kodak Tri X 400 @ 400 with time recommended for Rotary Tube Processing in Kodak Publication F-4017.
Ferrysburg Fire Department, Ferrysburg, MI


EDIT: I usually use this machine to develop b&w film mostly. But yes you can also use this to do C-41 color, or E6. Put all your chemicals in a tub or better yet, a cooler with water, heat your chem to desired temperature. You might also want to warm the developing tank up first before you pour your first chemical in. You can find more detailed tutorials online on how to keep your color chemicals warm.

20 thoughts on “Using Unicolor Motorbase Developing Roll Film with Small Tank (Home made rotary tube processing)

  1. This is awesome! I just bought one of these motor bases and I’ve rigged up the same thing using PVC pipe for the short metal developing tanks. I think that the long tanks (4 reels at a time and larger) will work just fine.

    Thanks for posting this.

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