Jobo expert drums and beseler motor base. It can be done! : LUSENET : Large format photography : One Thread

Hi all, this is not a question but a tip on using the Jobo expert drums with a regular motor base. Allow me to bore you with the story on how I discovered this. I ordered a Jobo CPA2 with the Jobo lift and an expert drum (4x5) from a mayor mail order company from NY ( you all know who I am talking about). These people in their infinite wisdom decided to send me a unit that had been returned by someone else, it hasd obvious signs of usage, the thermostat did not work and it even had dried water marks all over. Any way, with the Jobo lift are included two cog lids to place on the other regular drums like the series 2500 etc. I noticed that the cog lid on the expert drum was exactly like those provided as extras with the Jobo lift, furthermore I saw that the cog lid on the Expert drum was not an integral part of the drum lid, but just another little cog lid placed on the mouth of the drum lid. So I decided to put my money where my mouth is and got me a 15/16 box wrench to apply pressure from underneath the cog lid and try to get it out. My thinking was, if I was successful I could use the drum on a regular motor base with the red cap the other drums come with. So I proceeded to remove the cog lid and what do you know? it popped out after a little effort. When I tried the red cap that comes with the regular Jobo drums it fit perfectly! Now if you talk to Jobo they will tell you it cannot be used like this because the drum does not have a cup to hold the chemical, well duh! of course not, but it does have a light tight opening where you can pour in chemicals. For the last week I have been running tests with my new expert drums, both 8x10 and 4x5, on a beseler motor base and have been obtaining beautiful even negatives with no problems! If you are going to try this I have two tips or observations to provide: 1.- Don't used a unicolor motor base that reverses rotation, the reversal interval is too short and the drum does not complete a rotation since it is too wide. 2.- Don't get scared if you hear a loud crack when you are removing the cog lid from the drum lid. This is just the O ring on the cog lid that is really tight. You might mess up the lip on the cog lid, but who cares, you are not going to use it anyway! BTW I did not mess mine and was able to attach it back. 3- You defenitly need to get the foot pump to open the drums, and you will have to modify the pump to fit the new wider mouth. From Jobo the foot pump comes with a rubber stopper to fit the opening of the cog lid, obviously this will not fit the wide mouth once you have removed the cog lid. Go to a lab supply store and buy a #12 rubber stopper, drill a hole in the middle and place the hose from the foot pump into this hole. Once you see it you will know what I am talking about. What are the advantages of working this way? 1 you do not spend about $2000 to have the entire kit(which IMO the Jobo unit is a very cheaply made item). $1230 for CPA2, $233 for Jobo lift, $246 for Expert drum 4x5, $246 for expert drum 8x10. my cost $530. Two expert drums, foot pump and beseler motor base. Noth cheap but a lot better than $2000. 2.- you can put more chemical in the drum, the Jobo units have a problem with the motors if you overload the drum, they even sell replacements! a sure sign these motors burn up. With the motor base you can put all the chemical you want and there is no problem, heck if you burn up the motor base, go get another one used for $20 bucks, a lot cheaper than a replacemet motor for the Jobo unit. 3.- no space concerns, I keep all this equipment in a much smaller space than a Jobo unit would have taken. 4.- No fighting to make sure the drum is leveled. If you have worked with the expert drums, you know is almost impossible to place the lid so that the drum does not wobble when rotating. This wobbling might be good to insure even development, but it stresses the motor unit and eventually it will burn it up. 5- Slower rotation speed. This is not an advantage unless you are using easily oxidized developers like PMK or catechol.

What are the disadvantages? 1- no temperature adjustment ( I standarized my process to work at room temperature, so for me this is not a disadvantage).

Ok, I hope this information is usefull for those of you who had been wanting to use the expert drums but did not want to shell out the bucks to buy the whole set up. Good luck and many beautiful negs!

-- Jorge Gasteazoro (, August 19, 2001


Jorge, I wonder if your original Jobo CPA-2 was used, or as is stated in the Jobo CPA-2/CPP-2 owner's manual, showing water marks as you described simply due to run-throughs with post production quality control at Jobo? On the other hand, you may be right if the thermostat was unoperable?.... Andre

-- Andre Noble (, August 19, 2001.

Jorge, Thanks for sharing this! I've often wondered if there was a way to utilize the expert drums without going to the expense of a complete Jobo system. My darkroom stays at a pretty consistant temp. (as does my water supply, in summer, anyway) and this sounds like something I might want to try.

-- Robert A. Zeichner (, August 19, 2001.

A couple comments. I use an Expert 3005 drum on a Unicolor 352 base. I did have to modify the base with an electronic timer and relay to control the rotation switch times. I now switch after 2 revolutions. One thing Jobo says is that the expert drum should be turning when pouring in the chemicals. See Jobo website FAQ for details. I start the drum rotating and pour using a flexible funnel. Fairly easy and fast. Sounds like you're pouring the solutions straight into the drum then putting it on the base and starting. Looks like this approach is working for even development contrary to Jobo. I may try it next time as it is easier then the funnel method.

-- Chuck Pere (, August 19, 2001.


Defenitly used, I can maybe accept a few water marks on the rotation chamber, but to have the entire motor cover showing water marks, I dont think so!


You are welcome,I have gotten a lot of help from this forum, so I am glad to share something useful.


I don't know how to do the electronic thing you mention, but I am happy with the Beseler, it has a little bit faster rotation without being too much. As to pouring the chemical while it is rotating, I imagine Jobo recommends this because their drums spin so fast you get an even distribution of chemical, with your motor base you are wasting your time, just pour in the chemical, shake it and put it on the motor base.

-- Jorge Gasteazoro (, August 19, 2001.

I used to simply pour chemistry into my Jobo Expert 3010 then tip and rotate, till I saw evidence of uneven developing. I had always wondered about how critical this was but without any glaring problems I gave it little thought. I think it is best that the drum rotate when liquid is added, just to be safe. awkward, requires a long- necked funnel, but probably worth the efforts.

-- daniel taylor (, August 20, 2001.


I've been using the jobo expert drums with a bessler motor base for a number of years now. I've had success with the 8x10, 5x7 and 4x5 drums. I had not thought about taking the cog off of the lid, I might look into that.

I use a water pre-wash and then pour the chemistry into the drums. Never had a problem with uneven development. The drums are not full of chemistry so I never thought of putting a lid on the tank, never had any chemistry come out of the lid.

Just make sure the tank is level. I had problems with the tank "walking" off the motor base. Now, when I start to process film, I adjust the level of the tank before I do the pre-wash.

-- George Losse (, August 20, 2001.


I think it all has to do with the strenght of your developer, since I use a highly dilute developer I dont see any evidence of uneven developer of negatives, but if it works for you to have done while rotating, go for it!


Shame on you buddy!!! you could have let us know there is no need to use the jobo set up. :-)) Like you I don't see any chemical spill out, even with the cap off, but I put it there just for a little extra measure of light tightness, since you kept the cog lid on, I suppose that helps a little to reduce light spill into the mouth, but I figure better safe than sorry! Yes, the drums "creep" off the base, I make sure my motor base is level (checked with a bubble level), but still does creep, but I notice with the 4x5 and 8x10 the edges catch in the will and stop it from falling.

-- Jorge Gasteazoro (, August 20, 2001.

Shame on you buddy!!!

Sorry, I thought everybody new that you could spin those tanks on the motor bases. I wore out one motor base and thought about buying a Jobo processor to gain the temp control and to use all one system, but then I keep thinking about the cost of the motor base and use them.

I'm on my second one in about five years of processing film in the expert tanks.

The only problem I ever had was when an 8x10 tank "walked off the processor and made it to the floor. It cracked when it hit the floor, I thought I cracked too, my mouth hit the floor as I looked over at the tank now rolling on the floor. Only problem was the lid cracked when it hit the floor. It was in the fixer bath so it didn't hurt the film, but it scared the ---- out of me.

I use a bubble level on the tank before I start. I have found that the rubber on the wheels of the mtor base can also move. So now I place bottles of chemicals on either side of the tank to stop it from walking off the base.

-- George Losse (, August 20, 2001.

Just a comment on the need for a foot pump with the Expert Drums: I don't use one. My final rinse in the sink, I fill the drum with a hose. A rubber fitting over the hose end to seal the drum and force the lid off with the water pressure. It works great! Before getting the rubber stopper, I used my hand to form the seal: a little messy but still worked. If your lid is a little sticky putting it on and off, get a can of 100% dry silicone lubricant. Apply to both mating surfaces, and wipe off excess. (don't use wd-40, it has oil in it)

-- Gary Frost (, August 20, 2001.


Yes, George I also now place a bottle with water on the end that "walks" just in case. I figure the beseler motor bases would burn up, but is better than a buying the JObo set up, besides a new motor for the Jobo is like $500, I can buy 25 motor bases with


Great idea!! I should have thought of that. Ah well, the foot pump is the only cheap thing Jobo has, so no big deal!

-- Jorge Gasteazoro (, August 20, 2001.

My drum also walks. I made a u shaped wood base to sit it on. The ends keep the drum from walking enough to fall off the base.

-- Chuck Pere (, August 21, 2001.

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