JOBO CPA-2 and Expert Drum 3005

[Sal Santamaura]

...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...

My manual (08/96) recommends using the "4" setting for 3000 drums...I have been using the "4" setting with the 3010 with excellent results whether the film is color or B&W.

Thomas

I'm glad you're satisfied with the results, but don't know what rotation speed you are actually using since the date of your manual doesn't reveal the serial number of your processor or whether any motor / motor drive circuitry upgrades have been installed.

This thread finally motivated me to dig out the printed copy of a Web page Jobo no longer makes available that contains all relevant details. Herewith a transcription.

How do I properly set the rotation speed for my CPA-2 or CPP-2 processor?

For many years, JOBO has recommended rotation speed settings of 4 for use with our 3000 series drums and P for all other tanks and drums, to properly set the rotation speed. Now there are two different sets of speeds which need to be listed based on the type of motor in use in the processor. The following processors need to follow the new speed settings.

• All CPA/CPP processors with serial numbers greater than 22000.
  
• All CPA/CPP processors that have been upgraded with the new rotation motors (93026).

Both of these categories can most easily be identified by the screw head in the center of the cog on the rotation motor shaft. If there is a hex-socket screw (it uses an Allen key to turn the screw in installation) then it is the new style motor.

All older motors, using a slotted screw in the center of the cog on the motor shaft, still use the old speed settings shown below, and as listed in the instruction manuals that accompanied them.

Old Settings
0 - Off
F - 25 r.p.m.
3 - 40 r.p.m.
4 - 50 r.p.m.
P - 75 r.p.m.
6 - 78 r.p.m.
7 - 80 r.p.m.

*New Settings
0+ 25 r.p.m.
F - 46 r.p.m.
3 - 70 r.p.m.
4 - 86 r.p.m.
P - 86 r.p.m.
6 - 86 r.p.m.
7 - 86 r.p.m.

*These speeds are approximate and variations of 10-15 r.p.m. will not show up in your processing results

If you want to determine the proper speed settings for your processor, put a drum on the processor filled with an appropriate amount of water to simulate normal processing loads. Then swing the three-fingered switch out of the way, so the drum will only rotate in one direction, and then begin timing and counting the rotations of the drum. (Only use the single direction rotation for determining the correct speed dial settings. Always use bi-directional rotation when processing film or paper.)

That document from the old Jobo USA Web site's "Support" section, shown as Rev 001116, should clear up any confusion on the matter. From now on, whenever the subject comes up, I'll simply refer readers to this post.

[lumi]

This is good and solid info, also on rotation speed. I`ll report back my findings in this tread when the processor is up and running. I would welcome more suggestions on good developers and dilutions for 8x10 HP-5, specially combos that ensure enough strength to develop 5 sheets at a time. My negatives are scanned so that I need a somewhat soft negative compared to a traditional darkroom with a diffusion enlarger head.

Sverre
http://aurstadphotography.com

[Greg Blank]

What Sal doesn't tell you is he's an electronics engineer Anyway this post is most interesting because although I have been doing upgrades on the CPP2's for a while I noticed almost from the first upgrade that there is a defined difference in the second motor version and the newest one with the changes to circuitry. This conclusively answers that the changes of the circuitry and the suppressed motor produce less variability but more torque.

Thanks Sal!

I'm glad you're satisfied with the results, but don't know what rotation speed you are actually using since the date of your manual doesn't reveal the serial number of your processor or whether any motor / motor drive circuitry upgrades have been installed.

This thread finally motivated me to dig out the printed copy of a Web page Jobo no longer makes available that contains all relevant details. Herewith a transcription.

How do I properly set the rotation speed for my CPA-2 or CPP-2 processor?

For many years, JOBO has recommended rotation speed settings of 4 for use with our 3000 series drums and P for all other tanks and drums, to properly set the rotation speed. Now there are two different sets of speeds which need to be listed based on the type of motor in use in the processor. The following processors need to follow the new speed settings.

• All CPA/CPP processors with serial numbers greater than 22000.
  
• All CPA/CPP processors that have been upgraded with the new rotation motors (93026).

Both of these categories can most easily be identified by the screw head in the center of the cog on the rotation motor shaft. If there is a hex-socket screw (it uses an Allen key to turn the screw in installation) then it is the new style motor.

All older motors, using a slotted screw in the center of the cog on the motor shaft, still use the old speed settings shown below, and as listed in the instruction manuals that accompanied them.

Old Settings
0 - Off
F - 25 r.p.m.
3 - 40 r.p.m.
4 - 50 r.p.m.
P - 75 r.p.m.
6 - 78 r.p.m.
7 - 80 r.p.m.

*New Settings
0+ 25 r.p.m.
F - 46 r.p.m.
3 - 70 r.p.m.
4 - 86 r.p.m.
P - 86 r.p.m.
6 - 86 r.p.m.
7 - 86 r.p.m.

*These speeds are approximate and variations of 10-15 r.p.m. will not show up in your processing results

If you want to determine the proper speed settings for your processor, put a drum on the processor filled with an appropriate amount of water to simulate normal processing loads. Then swing the three-fingered switch out of the way, so the drum will only rotate in one direction, and then begin timing and counting the rotations of the drum. (Only use the single direction rotation for determining the correct speed dial settings. Always use bi-directional rotation when processing film or paper.)

That document from the old Jobo USA Web site's "Support" section, shown as Rev 001116, should clear up any confusion on the matter. From now on, whenever the subject comes up, I'll simply refer readers to this post.

[Jay DeFehr]

I use the slowest rotation speed possible with 510-Pyro, 1:100, 500ml. I don't think reversing direction is as important when using the Expert drums, because of the way they fill and dump, but I might be wrong. In any case, I've never had a problem.

[tgtaylor]

I'm glad you're satisfied with the results, but don't know what rotation speed you are actually using since the date of your manual doesn't reveal the serial number of your processor or whether any motor / motor drive circuitry upgrades have been installed.

Sorry 'bout that. My manual came with the CPA which I purchased new and has a serial number greater than 22000 so it has the latest motor.

Thomas

[Sal Santamaura]

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

...My manual came with the CPA which I purchased new and has a serial number greater than 22000 so it has the latest motor...

So you're running at around 86 rpm. Since the results are satisfactory to you, the only apparent advantage of slowing the drum down to Jobo's recommended 46 rpm might be somewhat longer times. If your current process steps are so short they make staying on time difficult, that could be good. Otherwise, if it works for you, just keep on keepin' on.

[Sal Santamaura]

...I would welcome more suggestions on good developers and dilutions for 8x10 HP-5, specially combos that ensure enough strength to develop 5 sheets at a time. My negatives are scanned so that I need a somewhat soft negative compared to a traditional darkroom with a diffusion enlarger head...

In my case, ambient air and water temperature were the determining factors in approaching this question. Here in southern California, tap water ranges from a low of around 67 degrees F in January to a high of approximately 80 degrees F during July through September. Without air conditioning, our house runs from the low 70s F in winter to about 80 degrees in summer.

I have both a CPA-2 and CPP-2, but, since the tap water is so warm in summer, couldn't make use of the CPP-2's cooling capability without also installing a chiller. Therefore, I've standardized on 2 process temperatures -- 75 degrees F during the cooler months and 81 degrees F at other times. This constrains developer and dilution choice, since times shorter than 4 minutes, even in Expert drums, definitely lead to uneven results.

I don't process any 8x10 in the 3005 drums; those are reserved for 5x7 and whole plate. The small number of 8x10 sheets I do develop are run in a 3004 drum. In order to meet the minimum developer quantity requirement while diluting sufficiently to keep times reasonably long, I use Xtol 1:1.5 in this situation, since it can get by with 100 ml of stock per 80 square inches of film. In a 3005, you'd be able to dilute the Xtol no more than 1:1 when processing 5 sheets of 8x10.

Assuming your ambient temperatures in Oslo are far lower than here, you have many more options, particularly using undiluted developers. I know that Oren Grad runs 8x10 HP-5 Plus in straight D-76; perhaps he will chime in with his time for that combination. Note that, unlike Xtol, D-76/ID-11 requires 250 ml of stock per 80 square inches of film.

While the recent bankruptcy caused a run on Kodak film, I haven't noticed any similar rush to buy up Xtol. At the moment, B&H has over 240 5-liter packages in stock. If I were you, I'd try Xtol 1:1 and, if you like the results, go with that. Unfortunately, I can't offer a starting time for the combination; I've only used Xtol at 1:1.5 with 320TXP, for which my protocol is a 5-minute presoak, then 7 minutes 15 seconds at 75 degrees F running at 46 rpm.

[tgtaylor]

I never thought about rotations/minute until your post above. I just set the rotation according to the Jobo manual and processing times according to Kodak's recommended time for the film with Xtol. But I just finished processing 2 sheets of 8x10 Delta in a 2830 tank and counted the bi-directional revolutions of the drum: 6 revolutions in 5 seconds = 72 revolutions/minute. But that was the bi-directional speed and not the unidirectional speed.

Thomas

[Sal Santamaura]

...But that was the bi-directional speed and not the unidirectional speed...

I don't think reversing makes a difference in speed. Jobo probably recommended disabling the reversing switch in that document just to make counting the drum's turns easier.

[tgtaylor]

I don't think reversing makes a difference in speed. Jobo probably recommended disabling the reversing switch in that document just to make counting the drum's turns easier.

I don't think so as the drum come to a complete stop before reversing direction and then must accelerate back to the rotational speed. It's easy to surmise that without the stop and and go of bidirectional rotation I would have had 7 revolutions in 5 seconds with unidirection rotation nstead of the 6 revolutions I got with bidirectional rotation. That would have gave me 84 RPM in the "P" setting which is close to the 86 RPM listed by Jobo and well within their margin of error. In making the count yesteday I was lucky in that the printed portion of the drum came to a stop each time facing me making the count easy to do.

Thomas