One Huge Print Drum

[darkroom_rookie]

Did some sketching for a possible 60x72" drum that could be used for RA-4 processing. Basically, here you have a combination of Beseler (central trough), Unicolor (chems at bottom) and wine barrel (drain placed low) designs applied to a drum which should be light and hand-holdable by a single person. Comments welcome!

 

[PKM-25]

Frotog - that's way more chemistry than you'd need one-shot in a drum. And a 40-inch circumference drum isn't forty inches in diameter! Don't worry - the math teacher didn't like me either.

Would you like a slice of Pi with that?

And Rookie, I heart homegrown darkroom stuff...

 

[frotog]

Frotog - that's way more chemistry than you'd need one-shot in a drum. And a 40-inch circumference drum isn't forty inches in diameter! Don't worry - the math teacher didn't like me either.

Not when you're using FB paper and dektol 1:3.
I have five ss mural troughs. When not in use they nest together and fit in the six inch high space under the bottom shelf of my sink.

 

[DREW WILEY]

When not in use my drum sits on its tail. Go figure the floor space it takes up. The biggest problem
calculating chem volume is not the amt needed to do the job and keep the length of the drum
continuously wet (only about a qt), but the efficiency of the drum in maintaining critical temperature
inside. Dektol is a piece of cake. Color is more finicky. One needs enough volume to offset ambient
air temp before drifting. This is a matter of both design and conditions. To make things equal, you'd
need an efficient water jacket around the developer trough, or an attached thermoregulator with
a circulating pump for the chemistry itself. I'm not implying that your trough system is not adequate
to the task you've assigned it - but drums are way more versatile. But there is a point in size when
fiber-based paper will collapse in them.

 

[frotog]

Good for you Drew - nothing like a serious process to keep you busy!

In my posts I've been addressing the Op's interest in making large fb b/w prints.

For color I mostly inkjet and digital c these days. It's been over a year since I last made an analogue c print over 20x30". But when I do I find it most efficient and timely to rent space in a service bureau with a 50" rt. Talk about versatility!

Nonetheless, I'd be interested in seeing some pictures of your diy temp-regulated drum rig. Sounds nuts.

 

[DREW WILEY]

It's really simple. If I want to set up a 50 inch roller transport system I can have one for the asking.
Lots to go wrong. With a basic drum and drive gearmotor, there's very little that can't be easily
fixed. The water tempering bath is on the side. My first really good drum and thermal regulator system was designed by a guy name David Seriqui. But he also marketed a multi-trough system for
b&w mural paper like you use, but with a chain-driven external roller transport, either hand or gearmotor cranked.

 

[frotog]

Indeed. Lots to go wrong.

 

[PKM-25]

Well I finally got around to doing a serious session of fiber 20x24 in the 3063 drum, flawless! I trimmed off about 2/3rds of an inch off the 24" side and then lined the paper ends up in an area of the drum with low ridges versus tall. No buckling, no corrugation, no problems. In fact because the paper gets so wet during the pre-wet and is a longer processing time, I feel it is far less prone to streaking and looks beautiful.

And as far as washing, taking some of the dividers out of my 16x20 Eco-Wash worked great, 4 prints at a time with a gentle fold and it's all good!

The drums rock!

 

[frotog]

Actually, trays rock. Your drum rolls.

 

[DREW WILEY]

My drum rocks and rolls. It was actually an amazingly simple conversion. I simply installed one eccentric roller on one of the pair of drive rods. Three regular friction rollers and one eccentric, so with each roatation there is also some tilt back and forth along the length of the drum.