JOBO CPA-2 and Expert Drum 3005

[lumi]

I just bought my second JOBO. I had one years ago until the motor broke down and I have been handrolling up to now. The reason the motor broke down was probably because I put too much developer into it (up ti 1 litre) having read Steve Anchell and the importance of sufficient amount of developer. When handrolling I use one 0,9 litre of X-tol 1:1 to develop 5 sheets of 8x10. I am now concerned that this will be too much for the CPA-2 processor and that I have to chance to another dilution or to a different developer. Any ideas? I guess many 8x10 users are used to develop 5 sheets at a time in their JOBOs. What developer do you use, and what dilution do you use -- and how much developer do you use?

Thanks,
Sverre

[Kimberly Anderson]

3005 drum here. 1000ml, using Pyro. Unidirectional processing, no reversal. CPA-2 and CPP-2 processors using this technique. No problems...

[Sal Santamaura]

I use a full liter in Expert drums all the time on CPA-2 and CPP-2 processors with no problem. The key is which motor and motor drive circuitry yours has; only the latest processor versions are capable of doing this reliably. The actual rotation speed also varies (for a given setting of the speed dial) depending on motor.

See this

http://www.jobo.com/jobo_service_ana...etins/b019.htm

for complete information. Also note that the Jobo processor manuals weren't revised when motor / motor drive upgrades were implemented, so they still say to use "P" for film. That's incorrect and will result in extremely high rotation speeds.

For a CPA-2/CPP-2 with the latest motor and Expert drums, use the "F" speed setting. This will rotate the drum at around 45 rpm, optimum for (non-pyro) sheet film development. Those using pyro developers have suggested using the slowest possible rotation speed instead to prevent developer oxidation.

[Kimberly Anderson]

i go the slowest I can and I am using Pyro...good clarification Sal.

I have also used the older versions of the CPP and CPA and have not had any problems. This was in an educational setting where I had all kinds of students using the machines. I have heard that the older machines have electronic and motor problems, but I have not experienced those. This is running more than 8 different machines over the past 15 years at various schools.

[lumi]

Thanks for all help. I`m afraid I don`t know if the motor on my CPA-2 is upgraded or not, the unit is on its way from Germany to Oslo, Norway. I guess Michael has a point opting for unidirectional processing which puts less strain on the motor. I alway thought reversal was mandatory for high quality result. May be I worry without reason.

[Jim Noel]

If your machine will not handle the liter of chemistry, especially at the necessary slow speed, try using 800 ml and/or be prepared to gently assist the rotation in one direction. I don't know why, but mine will handle it one direction w/o assistance, but not the other.

[tgtaylor]

Also note that the Jobo processor manuals weren't revised when motor / motor drive upgrades were implemented, so they still say to use "P" for film. That's incorrect and will result in extremely high rotation speeds.

For a CPA-2/CPP-2 with the latest motor and Expert drums, use the "F" speed setting. This will rotate the drum at around 45 rpm, optimum for (non-pyro) sheet film development. Those using pyro developers have suggested using the slowest possible rotation speed instead to prevent developer oxidation.

My manual (08/96) recommends using the "4" setting for 3000 drums for all processes except the Ilforchrom P-30 and P-30P process which the "F" setting is recommended for all drums including the 3000 series.

I have been using the "4" setting with the 3010 with excellent results whether the film is color or B&W.

Thomas

[Kimberly Anderson]

Thanks for all help. I`m afraid I don`t know if the motor on my CPA-2 is upgraded or not, the unit is on its way from Germany to Oslo, Norway. I guess Michael has a point opting for unidirectional processing which puts less strain on the motor. I alway thought reversal was mandatory for high quality result. May be I worry without reason.

When you get it look at the screw that holds the main gear on. If it's slotted, you have the older motor. If it's an allen-head, you have the newer motor and electrics.

Do a search for unidirectional development. There are a lot of people who swear by it, and a lot that don't swear by it. In the end, it's just like everything else, you have to experiment for yourself. I won't process reversing the motor any more. I think it helps to make the motor last longer.

I also process on the slowest setting possible. HP5+, Pyro, and a 2-minute rotating pre-soak.

[Michael Graves]

Personally, I've standardized on 500ml of solution at a rotation speed of 4 (whatever that is). I've been getting fully developed negatives using Rodinal 1:50 and HC-110 1:50. And yes, I know that isn't a conventional HC-110 dilution, but that way I only have to remember one dilution ratio. It also gives me a more comfortable developing time.

[lumi]

Thanks again. I´ll check what kind of motor I have when the unit arrives. Then I will try out 5 sheets 8x10 HP-5 in 900 ml Xtol 1:1 unidirectional.

Sverre Aurstad
http://aurstadphotography.com/