I'd take the brushes out, clean the slots very well, Shim them if needed (JB Weld or something) so the brushes move smoothly in and out only. How much brush is left? If you have plenty left, I'd be patient and do some bench running to re-seat the brushes on the arm.
Just a quick update. I haven't received an email back from the 'Joboman', but I did email an industrial supplier in Germany.
They said that an alternative OEM motor would be a SWF 402.932 - http://smolka-berlin.com/onlineshop/...r_24_V_DC/4390
The thing that has me concerned is that it is rated with an idle speed of 50 RPM. I was always under the impression that the Jobo CPE-2 ran at around 70-80 RPM. Can anyone please confirm this for me if at all possible?
I have also been able to source a sort of replacement locally, but will require some work to get fit (including a coupling, or a new collet for the magnet chuck). This unit is rated at 107RPM @ 24 V, which should reduce down nicely if I use a 20V power supply (which I am doing at the moment).
contains information about rotation speed of processors CPA-2 and CPP-2. I don't know if that applies to CPE-2.
The normally recommended speed is 75 rpm. That's, in my Jobo, slightly "faster" than the P position, I develop my films placing speed control half a notch beyond P as I measured this to give 75 rpm. One might think that P stands for "Paper" and F stands for "film" but apparently that is not.
The P and F did stand for 'paper' and 'film' respectively at one point, until Jobo decided later that they weren't the best recommendations. From the Jobo Quarterly of 1999, 4th Quarter:
Originally Posted by Diapositivo
and (the table formatting will fail here):
What Speed is it Really?
by Ken Owen
Recently a JQ subscriber wrote and asked us to be more specific about processor settings when we write about film and paper processing tests. This is an excellent suggestion we will try to implement in the future. However, it caused me to think that perhaps it might be useful for you, the reader, if I described the various processors and how to "translate" rotation speeds for your machine.
First of all, let me make you aware that you do not need to get too fussy about the precise speeds in use. As a percentage of speed, it appears that an approximately 30% speed shift is required to show a significant difference in the densitometric tests of the resulting images. Years ago, we tested this very concept and found that the 75 rpm speed had to be slowed to about 50 rpm before we showed a 0.03 logD difference in the results. (0.03 logD is roughly equivalent to 1/10th of one ƒ stop.)
Another factor that will affect the speed of the rotation motor is the weight of the load on the motor. A 1526 Combo tank used to process one 8x10 print only needs 50 ml of solution, so there is not much drag on the motor. On the other hand, a 3005 Expert Drum for 8x10" sheet film may contain up to 1500 ml of solution. Plus, the vents on the bottom of the Expert drum draw in water from the processor’s water bath, so there can be a very large drag on the motor when using this drum. For best results, you will need to test your processor speed with the tank or drum loaded with the amount of solution you plan to use in the actual process. On the CPA-2 and CPP-2 manual processors and the ATL-1 AutoLab, this will make a difference in your speed setting. On AutoLab processors from the ATL-2 on up, the speed is microprocessor-controlled regardless of the weight of the drum load, so you don’t have to worry about it.
To test the rotation speed on the CPE-2 (not Plus) CPA-2 or CPP-2, begin by loading the tank/drum with the amount of solution you anticipate using. Then set the speed to the anticipated setting on the dial. Now swing the three-fingered switch out from behind the rotation motor’s magnet or gear. This will allow the motor to rotate in one direction only. (Note: Testing such as this is the only time we currently recommend single direction agitation. For all normal film processing we recommend bi-directional agitation.) Now with the tank/drum rotating, start a stop watch, and begin counting the revolutions by noting the passing of the label with each revolution. After one minute, you’ll know the rotation speed. Obviously you can also count the revolutions for 15 seconds and multiply by 4. But the point is this: it’s easier to determine the rotation speed than it is to take your pulse.
Now let’s get down to the particulars for each processor.
The DuoLab, CPE-2 Plus, ATL-1000 and ATL-1500, as well as the new ATL-500 and ATL-800, all run at a fixed speed of approximately 75 rpm. So there’s no rotation speed adjustments or testing needed here. (DuoLab owners will note that their agitation motor does not reverse direction. When we first saw this we were concerned about the possibility of streaks. However, after testing with BW, C-41 and E-6 films, we found no sign of streaking or bromide drag. We believe this is due to the limitation of small size tanks it is capable of handling. It works perfectly!)
The older CPE-2 processors had two rotation speeds, marked 1 and 2. They were approximately 25 and 65 rpm. There was some variation with individual units, but probably not enough to make any difference in your results. With magnet drive you can use either speed setting, but with the JOBO Lift you must use the #2 setting. The #1 setting doesn’t have enough power to keep on doing the rotation with the additional drag of the Lift arm. At least not for long.
The CPA-2 and CPP-2 have continuously variable speed controls. The dials are marked 0, F, 3, 4, P, 6, 7. Originally the F and P stood for film and paper. But with more research, Jobo learned that almost every process ran better at higher speeds. Today, we recommend as a basic guideline that all tanks or drums that couple to the lower spigot on the Lift arm be rotated at speed P, and that all drums that couple on the upper spigot, be rotated at speed 4. (Those of you running with the magnet coupling will use speed P for all tanks/drums.) These two speeds will be close to 75 and 50 rpm respectively. The single exception to this rule is that Ilfochrome prints should be rotated at speed F (approximately 25 rpm), to help hold down the contrast.
Those of you with AutoLab processors ATL-2 and higher know that you simply select the specific rpm setting you need, without any translation required. On earlier models you could select Quick Start, 25, 50, 75 or 100 rpm, or Disc. The Quick Start was an automatic speed variation program for Ilfochrome. It started out at 100 rpm for the first 25 seconds, and then slowed down to 25 rpm for the rest of the chemical time. For water rinses, it runs at 25 rpm the whole time. The Disc setting was 100 rpm in a single direction. Disc film needed a very high agitation, and reversing directions reduced the agitation somewhat.
Now you are fully armed with virtually all the rotation speed information. If you see any articles written about any JOBO processors that indicate some sort of speed setting, you should be able to convert that to useable information for your machine.
JOBO Processor Rotation Speeds
Here is a quick summary of the various speeds used in JOBO Rotary processors.
Processor Model : Rotation Speeds
DuoLab: 75 rpm
CPE-2: 25, 65 rpm
CPE-2 Plus: 75 rpm
CPA-2, CPP-2, ATL-1: 20-80 (variable) #4 is approx. 50 rpm P is approx. 75 rpm
ATL-500, 800, ATL-1000, 1500: 75 rpm
ATL-2, 2-Plus, 3, ATL-2000, 3000,ATL-2200, 2300, 2400, 2500: Specific microprocessor controlled rotation speeds of 25, 50, 75, 100 rpm, with some exceptions on newer models.
Hoffy, I believe that the CPE2+ runs at 75 rpm, whilst the earlier CPE2, which I have, runs at two speeds, 25 rpm and 65 rpm.
I have been developing without any problems 135 film at the 25 rpm speed for at least the last 3,000 rolls of film, including 4 rolls last Sunday afternoon after a morning shoot.
I also develop at 25 rpm 4x5" and 120 roll film, have done for years.
This includes B&W neg, B&W reversal, E6 and C41, in all formats.
I only use the 65 rpm speed when doing the wash, which is 5 minutes.
I believe the two speed of the earlier CPE2 was to ensure that film developed in the 1500 series of smaller tanks, rotated at the same exterior speed as the larger 2800 paper tanks.
My personal experience with my machine was that it was working too hard at the higher speed, so I just put onto the lower speed, been using it ever since.
It's also done EP2 colour neg paper and the later RA4 colour neg paper, until I purchased a Durst Printo in late 1990.
I have a spare CPE2 which was given to me, one day if it's needed I'll migrate the lift mechanism, if not I'll just keep on using it.
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The higher speed (75 rpm) was recommended by Jobo for film development. That said, I doubt that you would see much difference with 50 rpm. I would not hesitate to use it.
Excerpt from two posts earlier, written by Ken Owen in Jobo Quarterly, 4th Quarter 1999:
Originally Posted by RalphLambrecht
Validates Ralph's doubts, straight from Jobo.
Years ago, we tested this very concept and found that the 75 rpm speed had to be slowed to about 50 rpm before we showed a 0.03 logD difference in the results. (0.03 logD is roughly equivalent to 1/10th of one ƒ stop.)
Thanks Lee, I've never read that.
Hoffy needs to increase development time by 1.14% to make up for it.
Seriously, I have never measured it, but I'm sure there will also be a difference in rpms between a small tank (light load) and a fully-loaded, large tank as well. I have never heard a bout a concern in this regard.
Just make sure you get the strongest motor possible, still fitting your package and electrical specifications. The CPE-2 motor was underpowered as far as I'm concerned.
Thanks for the input peoples. From what I have read, the old CPE-2 motor was rated at around 0.5 Nm torque, at the highest speed. The replacements I am looking at are rated at 0.7Nm at the highest speed. I can also source one that is rated at 1.2Nm, but is a bit more expensive and a bit slower spinning.
That's the standard difference between constant agitation and even more constant agitation.
Originally Posted by RalphLambrecht
When I got my CPE-2 in Köln in the fall of 1982, Jobo was recommending the 25 RPM speed for film. I did have very poor results with a CPE-2 and the 2509 (non-N) reels and 2501 reels with several developer/film combinations. Highly uneven development and surge patterns on 4x5, and strong surge patterns from the radial braces on the 2501 reels. I found out much later that they changed recommendations to a 5 minute pre-soak and the higher 65 RPM speed for film processing. A quick test about 8-10 years ago showed that those recommendations greatly improved the results. But I don't use it any more because it's much faster to process in a hand tank than to set up the Jobo, and I use varied agitation frequency as a process control. I originally bought it because I was forced to work in an unheated 13°C basement for a number of months.