After the sale of the Jobo ATL-2000 I decided to build my own developing tank.
I took the idea from a japanese guy that posted a video on youtube. But instead of buying a cheap water tank I assembled one using polypropylene plates.
I did that because I wanted to make sure I would be able to put in and out all my Jobo and Paterson drums – except the largest one – without have to move the rollers along their axis.
For processing black-and-white films the Jobo and Paterson drums are positioned over the rollers and it´s not necessary to fill the tank with water.
To develope chrome films I fill the tank with 20 to 25 liters of water (it depends on which drum I´m going to use) and the Jobo or Paterson drums are positioned under the rollers. The floating force pushes the drums against the rollers.
To heat the water I use a aquarium heater. It is really fast and easily keeps the water at 38°C.
The drums rotate by a windshield wiper electric motor and a 12V DC power unit.
It needed at least 7A to run the motor but I used a more powerful supply that delivers 11A.
To change the rotation direction of the drums I asked a friend to build an electronic circuit to invert polarity each 5 or 6 seconds (the black box).
All metal parts – but the motor – are made out of stainless steel. The two shafts are M8 threaded rods inserted into holes at tank walls and the rollers are precisely positioned to allow put in and out the drums.
One shaft connects to the motor by a metal piece with an internal M8 thread and is secured by a tightned nut.
The rollers are 100mm diameter with 8mm holes. The rollers that rotate the drums are fixed to the shaft by one nut each side tightned against the rollers.
The other two rollers rotate freely on the shaft and are hold in position by two nuts each side, tightned against each other.
It is very easy to operate, very ruged and will last for life. It just fits in my small bathroom and since then I processed over 200 black-and-white films (and ZERO chrome) with good results.
Here is a youtube video of the processor running a large Paterson tank.
And here a video of the processor running a small Paterson tank.
If you want to know more live a comment or email me (firstname.lastname@example.org) and I will do my best to help.