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_analog/us_analog/bulletins/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/

[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.

ThomasI'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. :D

[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. :D

[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

[Sal Santamaura]

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...I haven't checked this, and won't in the near future since my processors are only taken out to use occasionally (otherwise stored in closets), but suspect that the rotational speed is unchanged irrespective of reversing.

While rotational acceleration and deceleration in reversing mode take time and reduce the total number of turns you can count, they probably don't affect angular velocity between reversals. Once the drum is up to speed in a given direction, it's likely turning at the same rpm (until it starts decelerating) as it would during unreversed operation.

[ic-racer]

I think he means the average angular velocity is less with bidirectional operation.

[Sal Santamaura]

I think he means the average angular velocity is less with bidirectional operation.Yes, I understood that, but so what? It's the angular velocity the drum actually rotates at during most of its cycle that determines how chemistry and film are flung around. :)

[lumi]

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.

You are quite right, too warm developer is not an issue in Oslo. When handrolling I used Xtol 1:1 for 12 minutes at 20 degrees C for HP-5 ISO 320 (11 minutes for FP-4 ISO 100). Total volume 900 cl. I will probably continue to use Xtol but change to Ilford as soon as I find a good alternative. Sal, I see from earlier posts that you use (or used to use) Perceptol with good results and I might try that. Or DD-X. Thanks for all the good advice.

Sverre
www.aurstadphotography.com

[Sal Santamaura]

...Sal, I see from earlier posts that you use (or used to use) Perceptol with good results and I might try that. Or DD-X. Thanks for all the good advice...My choice of Perceptol, initially with Acros, was again based on a quest for longer times to cope with high temperatures. You might be just as happy with ID-11.

Bear in mind that 250 ml of stock Perceptol is recommended per 80 square inches of film. For DD-X, 62.5 ml of concentrate is needed for each 80 square inches of film. These minima apply regardless of dilution used.

I hope my advice has been good -- you're welcome.

[Greg Blank]

I made this video for the recently published article on Jobo drums.

Here is the direct link. http://www.youtube.com/watch?v=D0ZsaHw93B4&feature=g-upl&context=G20d3175AUAAAAAAABAA

Shows the directional change of the drum on the processor using a clear version of the Expert drum.



I haven't checked this, and won't in the near future since my processors are only taken out to use occasionally (otherwise stored in closets), but suspect that the rotational speed is unchanged irrespective of reversing.

While rotational acceleration and deceleration in reversing mode take time and reduce the total number of turns you can count, they probably don't affect angular velocity between reversals. Once the drum is up to speed in a given direction, it's likely turning at the same rpm (until it starts decelerating) as it would during unreversed operation.

[Kimberly Anderson]

Well gang, I did 14 4x10's yesterday in the 3005. Rotation between F and 3, 2-minute pre-soak, PMK @68 deg. for 18 minutes. Unidirectional rotation. They all look perfect. No issues. I am going to slowly increase my development temp and decrease my development time. I think 18 minutes is too long for development on a Normal negative.

The video showing how the drum works is very interesting. I wondered how it all came together on the inside of the tank.

[Sal Santamaura]

i go the slowest I can and I am using Pyro...


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


Well gang, I did 14 4x10's yesterday in the 3005. Rotation between F and 3, 2-minute pre-soak, PMK @68 deg. for 18 minutes. Unidirectional rotation. They all look perfect. No issues. I am going to slowly increase my development temp and decrease my development time. I think 18 minutes is too long for development on a Normal negative...Thanks for the update. I can't tell from your posts what actual rotational speed "between F and 3" is on the processor you're using now. Which serial number / motor upgrade does it have?

[Kimberly Anderson]

no motor upgrade, low serial number. I'll mark it with some tape next time and count actual revolutions...

[Sal Santamaura]

...I can't tell from your posts what actual rotational speed "between F and 3" is on the processor you're using now. Which serial number / motor upgrade does it have?


no motor upgrade, low serial number. I'll mark it with some tape next time and count actual revolutions...According to the Jobo document posted above, that means you should be right at 45 rpm -- damn near perfect, unless it causes too much oxidation of the pyro. :)

[tgtaylor]

I haven't checked this, and won't in the near future since my processors are only taken out to use occasionally (otherwise stored in closets), but suspect that the rotational speed is unchanged irrespective of reversing.

While rotational acceleration and deceleration in reversing mode take time and reduce the total number of turns you can count, they probably don't affect angular velocity between reversals. Once the drum is up to speed in a given direction, it's likely turning at the same rpm (until it starts decelerating) as it would during unreversed operation.

It's been a while since my physics courses in college but I believe that angular velocity is considered a vector quanity and a vector has both magnitude and direction. That would seem to imply that If the drum changes direction during rotation then the liquid inside must also at some point come to a stop and also change direction. If that is true then the average angular velocity would be zero as the vectors would cancel each other out.

Thomas

[Sal Santamaura]

...If the drum changes direction during rotation then the liquid inside must also at some point come to a stop and also change direction. If that is true then the average angular velocity would be zero as the vectors would cancel each other out...Not quite sure what you're getting at, but, for a really good look at the liquid behavior, go to the video in Greg's post #26 link, expand to full screen and make liberal use of "pause." Between 0:45 and 1:09 provides the best view.

[Greg Blank]

Thanks Sal. In direct response to Thomas, liquid never comes to a complete stop- and surely not in these drums while the drum is in any part of the process of spinning. One can argue the physics of that I am sure, the closest thing one could say concerning stopped liquid might be be ice, hopefully your tap water is not that cold. :D

I did the best with that video I could, it was done with my humble Iphone and no special video editing skills, knowledge or software. Just tried to make it functional and somewhat helpful as a well as self promotional.


Not quite sure what you're getting at, but, for a really good look at the liquid behavior, go to the video in Greg's post #26 link, expand to full screen and make liberal use of "pause." Between 0:45 and 1:09 provides the best view.

[John Powers]

Thank you Sal,

Your chart clears up several mysteries.

The CPP-2 I am using is the old slot screw or early motor. I use it on #4 with Rollo Pyro. My spare has a hex screw. Without your information that would have been quite a surprise when I plugged in the spare, set it to #4 and thought someone supercharged my Jobo.

Thanks,

John

[livan]

You are quite right, too warm developer is not an issue in Oslo. When handrolling I used Xtol 1:1 for 12 minutes at 20 degrees C for HP-5 ISO 320 (11 minutes for FP-4 ISO 100). Total volume 900 cl. I will probably continue to use Xtol but change to Ilford as soon as I find a good alternative. Sal, I see from earlier posts that you use (or used to use) Perceptol with good results and I might try that. Or DD-X. Thanks for all the good advice.

Sverre
www.aurstadphotography.com

Well, maybe I should move to Oslo then. :D I have recently moved to southern California with my family and after one month I already feel like it is a big issue here. I have a CPA-2 but now that the tap water is unexpectedly warm I definitely have to install a chiller in the next couple of weeks. For now I had to get a rental chiller (http://us.aggreko.com/products-services/rental-cooling-and-heating/chiller-rentals/) because buying the house and new furniture made me run a little bit low on cash. The question now is - which chiller should I invest in?