Jobo CPE-2 motor overhaul

[hoffy]

Howdy,

Only after 3 darkroom sessions since I bought it (used, of course), my Jobo CPE-2's motor cried enough. It was always going to be a risk, as when I bought the processor it wasn't running, but this was due to a failed power supply. I had been running it using a 19V 30amp lab supply, so I am pretty sure I had not caused it to fry (after some research, I had found the the jobo CPE-2 supply was 18 volts Max)! What happened is it started to progressively get noisier and then stopped turning.

Anyhow, there was nothing to be lost, so I decided to pull it apart to see why and IF I could fix it.

Below is the exploded view. As you can see, there is plenty of grease in the gearbox

Jobo CPE-2 Motor, Exploded view by hoffy37

Looking at the bell end, you can see quite a bit of black around the brushes, suggesting a lot of arcing

Jobo CPE-2 Motor, Bell End by hoffy37

The can and magnets all look fine, but the can end of the shaft and the bush did seem quite dry

Jobo CPE-2 Motor, Can End by hoffy37

The armature shows a lot of carbon buildup, again suggesting bad contact

Jobo CPE-2 Motor, Armature by hoffy37

And finally, the culprit. My suspicions is that this brush caused the motor to fail finally.

Jobo CPE-2 Motor, Burnt Brush by hoffy37

It looks like the plastic has melted, which has deformed the slot. The brush had been rocking backwards and forwards and would not move freely in the slot. I am surmising that this has caused bad contact, arcing and heat buildup and finally failure.

I tried to clean the arm and the brushes as good as I could and re-assembled the motor. It seemed to spin fine in one direction, but was really sluggish in the opposite. To me, this suggests that the rocking brush is probably the cause for this bad performance. I had thought about working out a way to sleeve the brush slot, but haven't come up with a good solution yet.

But, I have also been looking for replacements. I was wondering whether something like this would be OK (yes, I would be up for some cutting and shutting to get things to fit):
http://www.crestmi.com.au/planetaryGearMotor.php
I am afraid that this may be as gutless as the original Jobo motor, as it only gives 0.06Nm at 12V, but it would easily fit(with a bit of fettling)

The other option from this website is a 10W 0.83Nm motor, that will spin at 83rpm @ 12V. This one is a bit more of a tighter squeeze, which will probably mean moving some of the components to get it to fit, but it should be possible
http://www.crestmi.com.au/DC_precision_gearmotors.php#Z2D

The other thing to note is these motors have 8mm shafts, so I would need to make an adapter.

I hope this at least shows others what the internals look like and hopefully give someone some inspiration (or give me some advice on how to fix this one!)

Cheers

 

[rcam72]

Nice post Hoffy. I have an older CPP-2 and occasionally think about what I'll do when it finally craps out. Have you contacted the JoboMan. He seems to be the go to guy for JOBO questions and parts. Maybe he'd be able to point you in the right direction regarding a suitable replacement motor.

http://www.darkroomdoctor.com/Home_Page.php

ZoneIII has a thread, (there was a url link here which no longer exists), and he mentions a second possible source for parts/information but I keep getting a DNS error so I'm not sure if the link is good or not.

Thanks for the pictures and good luck with the repairs.

-Raul

 

[RalphLambrecht]

Hoffy

These are the contact details for the former Jobo Plant Manager(?). He is now retired and makes a living repairing and servicing Jobo's equipment. I haven't dealt with him yet, but he might be able to help you.

Fotolaborservice
Klaus Dieter Seynsche
Feldstraße 41
51702 Bergneustadt
Tel: 02261 – 41114
www.fotolaborservice.de
info@fotolaborservice. de

 

[hoffy]

Thanks rcam and Ralph. I have sent some emails. I'll see what they say and report back.

Cheers

 

[Paul Green]

Klaus probably won’t be able to help you sadly; I contacted him recently to ask about a motor for my cpe2 since it died. He explained that the only option was to buy a motor for the cpe2+ which needs modding to fit the processor case, he sells them for around 100 Euros.

 

[RalphLambrecht]

Actually, that may be a good thing, because the CPE-2 motor was just too weak. I bought a used CPE-2 Plus after my CPE-2 died and I'm much happier with it. It cost me less than 100 Euros by the way, but I wouldn't mind to fit a new motor into the old CPE-2, just in case.

 

[Nicholas Lindan]

You should be able to buy replacement brushes. Jobo didn't make the motor - if you can find out who did then you may be able to find brush kits.

 

[John Koehrer]

Haven 't there been several threads regarding windshield wiper motor as a replacement? Relying on a somewhat dubious memory function I believe they were BMW/Bosch 12V.
Junkyard as a source.

 

[RalphLambrecht]

What s so special about windshield-wiper motors?

 

[ic-racer]

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.

 

[hoffy]

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...932_Motor_Stirnrad_Getriebemotor_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).

 

[Diapositivo]

This link
http://www.jobo.com/jobo_service_an...ctions/instructions_manual_cpa-2_cpp-2_03.htm
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.

 

[Lee L]

This link
http://www.jobo.com/jobo_service_an...ctions/instructions_manual_cpa-2_cpp-2_03.htm
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:

http://www.jobo.com/jobo_service_analog/jq/jq9904.htm#A3994

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.

and (the table formatting will fail here):

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.

Lee

 

[Mick Fagan]

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.

Mick.

 

[RalphLambrecht]

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.

 

[Lee L]

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:

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.)

Validates Ralph's doubts, straight from Jobo.

Lee

 

[RalphLambrecht]

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.

Hoffy
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.

 

[hoffy]

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.

 

[Lee L]

Hoffy needs to increase development time by 1.14% to make up for it.

That's the standard difference between constant agitation and even more constant agitation.

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.

Lee

 

[hoffy]

Another quick updates. Joboman doesn't have any motors available at the moment.....looks like I am going to go for some form of replacement and make it fit. The little motor I have sourced locally is close, but not quite. As long as I can get the shaft in the right spot, I should be able to cut and shut to get it in. If it is a success, I'll post back and show exactly how it was done, in case others want to give it a try.

Cheers

 

[raoul]

Once this is all sorted and working, can I suggest writing an article or a web page for this? Plenty of people will be keen to keep these things going for as long as possible.

I'm fearing the day my CPE-2+ gives up the ghost!

 

[Mick Fagan]

Lee, that is quite interesting what you say about your experience in Köln with your CPE2.

I have been using the slower 25rpm speed for film since I bought my CPE2.

The hardest film to develop correctly is C41, mainly due to it’s very short developing time of 3’15”. Many processing faults will and can occur, with that very short developing time.

I had access to Kodak C41 control strips and the use of the densitometer at the industrial photo lab where I worked, the control strips were taken out of the freezer; within 1 hour they were in my Jobo.

Because I was doing one-shot C41, I actually had more consistent and generally better control strips than the lab dip and dunk bath. Which annoyed the ding out of the boffins running the baths, E6, C41, B&W, EP2 and R3 (Kodak’s reversal paper process).

I’ve never ever seen a commercial dip and dunk or roller transport film processor, B&W or colour process, that pre-soaked film. I have never pre-soaked any of my films on my Jobo.

I have processed thousands of C41, E6 and B&W (including reversal) 135 rolls and about a thousand sheets of Kodak Color Print 4x5” film, which had to be spot on as I was making a 4x5” transparency for four colour reproduction. Kodak Color Print film was a C41 process, processing had to be equal too, or if possible, better than E6, mainly due to the short 3’15” processing time.

I have the original 2509 reels without the later modifications and 1501 reels. I only do four 4x5” sheets to a reel though, my tests showed six sheets to a reel caused problems. Which is about the only processing fault, other than operator error, I’ve ever had with my CPE2.

Mick.

 

[Lee L]

Lee, that is quite interesting what you say about your experience in Köln with your CPE2.

Mick.

Mick,

My times were on the long side, using Rodinal and HC-110 at higher dilutions with a variety of films, but mostly Panatomic-X, Verichrome Pan, some Tri-X 135, and 4x5 Plus-X and Tri-X. The surge marks were consistent from batch to batch. The 2501 reels are 'open', with notched radial supports and no solid spiral elements. They have to be loaded on a special loader that provides a full spiral to keep the film on track. But after the reel is removed from the loader, there are just the notched radial spokes supporting the film. Those created the flow pattern that left uneven development surge marks. The 2509 also had a consistently placed flow pattern at about the place where the 2509 retainer clips should break it up. I haven't processed color film with Jobo equipment.

After I moved into an apartment in Bonn where I could use a large heated bathroom for processing and printing, I didn't need the Jobo and quit trying to solve the problems, or throw more money into the equipment. I just reverted to my stainless steel reels and tanks.

My more recent test with good results at the higher 65rpm speed and a pre-soak was with Rodinal 1:100 (same as in '82) but with Pan-F substituted for the discontinued Panatomic-X. I've never owned or tried the 1500 series tanks and reels, nor the 2502 reels, which have the full spiral rails. Shortly after I bought my setup, the newer reels came out, and the Expert series drums, which required that I replace the entire processor. I never spent the money on those after returning to the US in '83. Jobo USA was, however, very helpful in selling me the parts to convert to US voltage and frequency; a transformer, heating element, and fuse, which I installed myself. I had excellent results with Ektacolor and Cibachrome printing in the Jobo.

The Jobo Quarterly, 1994-1999, has a lot of info on the changes in recommendations over time. Apparently it was a Jobo USA publication sent to registered US purchasers, but since I bought in Germany, I was unaware of it. And it only started up 12 years after I had my problems, and when I was full-time care for a toddler and an infant. All Jobo Quarterly issues are currently (2011/6/1) online at: http://www.jobo.com/jobo_service_analog/jq/ but they have disappeared for periods of time during transitions at Jobo. It's well worth reading.

If I were doing larger batches of film and had a permanent position to leave the Jobo up and ready, I might have more interest in using it. I'm currently working on some ideas for rotating any standard size stainless steel tank standing on end on a driven 'lazy susan' type setup, with adjustable intermittent agitation using a microcontroller and no tempering bath. I just have to steal the bearings off my son's skateboard when he's not looking. I now prefer a Summitek Cradle for sheet film tray development.

I know that many others have used the CPE-2 with no issues, and perhaps I could have worked out my problems over time. But I was only in Germany for a year, and I preferred to spend my time photographing and printing rather than working out a set of problems that resulted from using equipment that I no longer had to use. It's also apparent from reading the Jobo Quarterly that I wasn't the only one having problems with uneven development. And there's the fact that all the reels I was using were shortly replaced with redesigned models (which I was unaware of at the time), and the recommended rotational speed for film development was changed.

Lee

 

[Mick Fagan]

Lee, I agree with you regarding the earlier reels having no spiral parts, I have used them a very little amount and didn’t like them. But I don’t remember any processing problems with 135 film.

Regarding the 2509 reels, I believe I have replicated what you call a “flow pattern” when using 4x5” film and six sheets, developing only four sheets at a time, eliminates that entirely.

One day I’ll acquire a newer 2059N reel with the addition that allows good flow, I’ll test again and maybe then, do 6 sheets at a time.

I assume yours doesn’t have a lift; the lift is a marvellous addition.

I have nearly always used ID11 or D76 at 1+1 dilution and nearly always Ilford 125 and 400 ASA films in their various guises over the years, until I discovered Neopan 400. But I am still in love with FP4+ in sheet film.

In those days we really were working in the dark, regarding developmental changes to most equipment. One either heard about something on the grapevine when you met someone in a camera shop, read about it in a magazine, or received information from shop staff. I first heard about Jobo from a photographer when he overheard someone complaining to shop staff about a leaking drum when turned upside down. The fact that it was a system, like most camera bodies, was a real bonus to me.

Without using either a playpen or a leash to keep a toddler out of trouble, I feel you would have been developing in the dead of the night; the things we do!

Mick.

 

[Lee L]

Thanks for the info Mick. The internet has certainly been a boon for keeping up with this kind of technical information, with tricks and tips. I haven't tried only 4 sheets on the 2509 reels. Perhaps I shall at some point, although I do 6 sheets in a liter now with a Summitek Cradle + 11x14 tray, and that would require two Jobo runs. I don't have a long film tank.

The Jobo was very common in Germany, and I'd sold them in two stores in the US before going over. Originally I'd been promised the use of a heated bathroom for processing film in the rooms we were letting, but the first time I did it, I was told to do it in the unheated basement. The Jobo was the only real solution, and their tempering box was not stocked locally and not much cheaper than the CPE-2. Mine didn't have the lift.

I also suspect that my choice of developers and dilution may have played some role in the problems I had, but I'm not really eager to spend a lot of time, film, and chemicals to nail that down. I was pleased that the higher speed and pre-soak did seem to solve the problems with one test run.

Lee