DIY "Expert Drum" - could this actually work?

I'm getting ready to get into 4x5 format (soon to get a Speed Graphic

4x5). </p>

I've checked various options for developing 4x5 format, and since I

already own a Jobo CPE2 processor (older) and 2500 series tank, I

thought this could be used for 4x5, too. The original Expert Drums

seem way too expensive, given that I was able to get the whole Jobo

CPE2 plus two tanks (one 2551 with 5 reels and one 4551 for prints)

for all of $70. :) </P>

I've ordered the appropriate reel for 2500 series drum... However,

until I get that 4x5 reel, which might take a while, I did some

reading, and came across several suggestions for DIY solutions, from

"tacos" developing, to other solutions. </P>

</P>

What I came up with is this: </P>

<img src="http://www.hrtranslations.com/slike/DIY_tubes3.JPG"> </P>

</P>

View from above: </P>

<img src="http://www.hrtranslations.com/slike/DIY_tubes2.JPG"> </P>

</P>

Do you think it could actually work on a rotary processor with lift?

 

The tubes will be smoothened some more, to avoid any possible

scratches, but I'm wondering if the flow of chemicals will be OK... </P>

I guess I'll see when I develop the first batch :) </P>

</P>

 

Denis<div></div>

I think this would work. Neat idea. You may need to play with the volume of developer to make sure you get enough to ensure even development. Use your fastest rotation speed, to make sure the developer gets spinned up into the center part of your tubes using a smaller volume of liquid. But if you get enough liquid to fill the tank to near the center post, then this should work at either speed.

 

Evenly fog a sheet of film, load it in, and take it for a spin. Let us know what you get!

 

Kirk - www.keyesphoto.com

Very clever. The differences are the cylinders in the 3010 are closed on one end and they have a divider in each cylinder to separate the 2 sheets of film in each.

 

Also the total volumn is limited by having no access to the interior of the drum except in the cylinder areas. You will need much more chemicals.

 

Finally there is no center filler tube. The chemicals go down the lift into the cover and straight into the cylinders.

 

By the way the clear plastic reels are not the latest. The latest are more slippery and are a white opage material.

Nice idea! You may have to clear the dye layer from the backs of the films after removing them from the tubes. The tubes in the expert drums are slightly barrel shaped so that the back of the film sits off the surface and chemicals can get in there. Maybe you could find a way to put some dimples or ribs in the tubes (plastic rivet heads?). Connect the tubes with glued on ribs and they won't rattle around. I'm curious to hear how it works!

 

Jim

I was thinking of perhaps drilling some holes in the tubes, at an angle, so that the angle "enhances" the inflow of chemicals.

 

Having never actually seen an Expert Drum, except on photos, I can only guess how the internals look (i.e. hollow cylinders).

 

The idea with plastic rivets also occured to me, since I'd prefer not to have the negatives "glued" to the insides of cylinders....

 

Well, I have some 4x5 Efke film coming soon, and I'll do some tests once I get my hands on it.

 

Thanks for the ideas!

 

Denis

To keep the film back away from the tube, get some 4x5 inch pieces of fiberglass screen. Insert the film/screen sandwich into the tube. I use such a sandwich when developing 8x10 in film in print drums.

I wouldn't worry about doing anything special to get developer to the back of the film. The BTZS tubes don't have anything special for that purpose and they work fine, the anti-halation stuff comes off in the fix and wash.

I've used tubes exactly that way in a stainless daylight tank to develop 9x12 cm film. If you have 1 1/2" pipe size tube, the 4" dimension of 4x5, or the 12 cm dimension of 9x12 will fit around the curl of the tube. I smoothed the insides of the ends of my (ABS) tubes by just slicing off a curl of plastic with a sharp knife blade, and have never had a scratch, though I now use them with individual caps with fabricated light traps for daylight filling and single sheet handling.

 

Your minimum liquid with this setup will be deep enough to cover a single tube at bottom of the tank, probably 40-45% of full tank volume, for rotary, or full tank for inversion.

 

Perhaps the perspective is fooling me, but is that tank really a bunch deeper than the length of the tubes? If it is, you might be able to put a sealed spool of some kind (inner and outer tubes with top and bottom sealed on) in the bottom to reduce your require liquid volume -- or are there two sets of tubes in there? If you're really ambitious, you could use foam and epoxy to make a molded unit that would fill most of the dead space around the tubes and further reduce liquid volume (beware of this unit floating if you use inversion, but shouldn't be a problem with rotary process).

 

How far it's worth taking this, of course, depends on your desired economy level -- you'll trade off time spent against future costs in chemicals or equipment, but of course after you get this just so, you may find you don't need the 2509n as badly as you thought anyway (and it only holds six sheets).

<B><I>Donald Qualls , jun 25, 2005; 06:15 p.m.</B> </p> </p>

Perhaps the perspective is fooling me, but is that tank really a bunch deeper than the length of the tubes? </I> </p> </p>

 

Donald, you're right - the tank is a deep one, takes 5 35mm reels/films or 3 120 films/reels. In the photos above, I took out 3 reels (left 2 bottom ones inside, on the core) and replaced them with tubes. </p>

 

However, yesterday I arranged for a purchase of a Jobo 2523 tank - it's the same series (Jobo 2500 series), but it's a lot shorter. It takes one 2059N reel for 4x5 film. I think the tubes pictured above will just barely fit inside that shorter tank, thus reducing significantly the amount of chemicals needed. </p>

That way I'll have the option of processing 4x5 on the rotary Jobo processor - either with the original 2059N reel, or with my DIY tubes.... :) </p>

 

Thanks for all the suggestions and help provided!</p> </p>

 

Regards,</p>

</p>

Denis

If you don't want to use plastic rivets to keep the back of the film off your tubes could you use hot melt glue from a glue gun - this worked in my orbital developing tank, but of course its far easier to put dots of glue on the bottom of a flat tank than inside your tubes.....