Using a motorized roller base to agitate film

[pschauss]

I have a Beseler motorized roller base which I use with a print drum for my larger prints. Now I am thinking that with a small bit of fabrication work I could use it to roll a 35mm/120 size stainless steel tank during the stop and fix processing stages. If I used this approach would my stop and fix times remain the same? I assume that I would want to slightly under fill the tank to get proper agitation. How much of an air space should I leave?

Note that I plan, at least for now, to continue doing my development stage with manual inversions to maintain consistancy in my processing.

 

[Paul Howell]

You might to check ebay for unicolor film drum for your motor base, be a lot less work.

 

[Lee L]

Peter,

I've been doing this for a number of years. It works fine with my SS tanks. No need for fabrication. I just put the film tank down on the rollers and it works. I make sure the levelling foot is set properly, and if off a little, make sure that it brings the lip of the plastic tank covers I use to bear lightly against the motor side. If it works off the other direction, it goes tumbling off the base. You could obviously try rubber bands as with the print drums.

I have only one caveat. When using Hewes 35mm reels and reversing motion (not all Beseler motor bases have a reversing switch), the film can work itself off the prongs that catch the 35mm sprocket holes, allowing the film to progressively slip off the reel, working a number of inches of film out of the reel and between the reel and tank wall. I learned to avoid this by stacking the Hewes reels in a consistent manner, switching the motor base to single direction mode, and orienting the tank so that the rotation tends to push the film in a direction that would load it onto the reel. I've not had any problems since.

I tend to use a full load of chemicals to make sure that it's sufficient volume to treat the film as normal. In any case, you want to have the tank at least half full when lying on it's side so that the entire radius of the film reel is submerged. That insures that all the film is given sufficient coverage by the chemicals.

This really takes the drudgery out of constant fixer agitation.

Lee

Oops! Late edit: I just realized that I forgot to mention that I use a SS tank with 4 x 35mm reel capacity. Shorter tanks will obviously need some mechanical consideration.

Haven't tried it, but perhaps a short length of PVC pipe with the SS tank inside of it. 4 inch pipe should do.

 

[Phillip P. Dimor]

There is a Unicolor Film Drum that will possibly work on the Beseler Base. It takes special 35mm and 120 reels. There are also jobo reels and tanks that will most likely fit. I'd never tried sticking my SS tank on there. If you go that route, try finding putting several rubber banks on the ends to keep it from walking off.

 

[drpsilver]

07 Dec 2007

Peter:

I have been using rotary processing of sheet film for many years. The JOBO tank 2551 I have been using (on a Beseler motor base) can accommodated 35 mm and 120 with a simple change of the reel used to hold the film.

Not only should you leaver some "head space" in the tank for agitation to occur you will probably needs to reduce development time because you are now constantly moving developer. I have noticed that there was a slight increase in negative contrast (once I found the correct development time for the rotary process) when I moved from "small tank" to "rotary" processing.

Hope this helps, and good luck processing film in a rotary tank.

Regards,
Darwin

 

[Shmoo]

07 Dec 2007

The JOBO tank 2551 I have been using (on a Beseler motor base) can accommodated 35 mm and 120 with a simple change of the reel used to hold the film.

Not only should you leaver some "head space" in the tank for agitation to occur you will probably needs to reduce development time because you are now constantly moving developer. I have noticed that there was a slight increase in negative contrast (once I found the correct development time for the rotary process) when I moved from "small tank" to "rotary" processing.

I agree whole-heartedly. I use the 2551 with a beseler motor base and it works well for 35mm, 120mm, 4x5 films. I don't use much more than 700-800 ml of solution in it, but the tank actually tells you what capacities to use. Also, if the motorbase only goes in one direction (doesn't automatically reverse), you'll have to flip the tank every minute or so to keep from getting streaking. I think most people start by decreasing their developing time by about 15-25%. It's a great way to develop film.

Good luck!
S

 

[Nick Zentena]

I use Jobo tanks to. Not much point changing stop or fix times. Stop is so short whats the point. Fix I'm sure from a chemical point will need a little less time but it's not worth worrying about IMHO.

 

[pschauss]

Thanks for the suggestions. I found that a stainless steel tank fits nicely into my 8x10 print drum. Wedging it in place with a paper towel keeps the tank from creeping out one end of the drum. ( Next time I think I will just put the end caps on the drum.) I just processed a short roll of Plus-X this way and the fixer cleared it nicely. Since I use a semi-stand development process for Plus-X (Rodinal 1+50 , three inversions every two minutes), I did not use the motor base for developing.