Problem with Jobo CPE2+ Can anyone help?

Roobarb · Aug 14, 2020

I have just bought this processor from eBay. Setting it up and trying it out, I noticed that the film tank was rotating very unevenly. Then it stopped completely. Investigating, it seems that the motor is still running, but the magnet has come loose from the motor spindle: I can spin it freely by hand. If I push it towards the motor housing, it bites and will (probably) run, but nit for long as it just clicks off very easily. I’m new to the machine and don’t want to make the problem worse, so any advice on how to fix the magnet onto the motor securely would be much appreciated!

MattKing · Aug 14, 2020

Welcome to Photrio.
Which "Richmond" are you located in?
CatLabs is the US (North American?) distributor and a good source for info and parts.

mpirie · Aug 14, 2020

There should be a screw head visible in the centre of the magnet which (when tightened) will clamp the magnet to the motor shaft.

If the screw's missing, pull the magnet off and find a replacement.

Mike

Roobarb · Aug 15, 2020

MattKing said:
Welcome to Photrio.
Which "Richmond" are you located in?
CatLabs is the US (North American?) distributor and a good source for info and parts.

Richmond outside London, UK.

Roobarb · Aug 15, 2020

Thanks

Roobarb · Aug 15, 2020

mpirie said:
There should be a screw head visible in the centre of the magnet which (when tightened) will clamp the magnet to the motor shaft.

If the screw's missing, pull the magnet off and find a replacement.

Mike

Roobarb · Aug 15, 2020

I’ll give it a try. Thanks for your help

Bikerider · Aug 15, 2020

Or find a similar screw. a whole lot cheaper than a new magnet (Experience of the price of JOBO spare parts!)

mpirie · Aug 15, 2020

If memory serves, it's a 4mm threaded screw around 6mm long with a pan-head.

Mike

Roobarb · Aug 16, 2020

I have tightened the screw up and the magnet is firmly attached to the motor shaft. However, the problem won’t go away. What the tank rotates there is do much lateral movement that the whole thing wobbled and judders. I can sometimes get it to estate more smoothly, but this is by trial and error rather than method, and the wobble returns if I detach the tank and replace it which, obviously, I would when processing for real. Even if the rotation starts smoothly, after a few minutes it is usually wobbling so much that the magnet detached itself from the bottom of the tank...

There is a little movement in the motor shaft, but it doesn’t seem excessive to me. The real problem seems to be that the tank is not sitting properly on the roller supports. This little unit isn’t really attached to the ridge of the bottom of the water bath but seems to move about, rocking with the rotating tank. In fact the ridge that it is supposed to be attached to doesn’t seem to line up with the motor shaft at all, and do the whole thing seems impossible to align correctly. I guess I must be doing something wrong, but I can’t think what it is.

Help! Please!

Kino · Aug 16, 2020

Pictures might help...

Roobarb · Aug 16, 2020

Kino said:
Pictures might help...

Roobarb · Aug 16, 2020

I have tried to show the alignment (or lack thereof) of the motor and roller supports, and the roller support unit on its own, because I am not convinced that this is the whole unit at it should’ve assembled. Thanks

Kino · Aug 16, 2020

Are you placing the rollers at the extreme end of the tank?

I see the misalignment you speak of... I wonder if it has been assembled from differing generations of the same unit and the shaft spacing was different? It might be a roller assembly from another model Jobo...

Why don't you ask Jobo?

http://www.jobo-usa.com

I know you are in the UK, but it is email support...

Roobarb · Aug 16, 2020

Ok thanks - I will.

I have been putting the rollers as far right as possible. Almost up to the red lid seal.

I am now running it with water just in the heated trough, not touching the rollers, and it is rotating much more evenly. I think part of the problem is that once in the water the rollers float and so become unstable. They can’t be fixed to the bottom of the unit at all. Is this normal?

Kino · Aug 16, 2020

No. That is why I think you might have an incorrect roller assembly. This is what it should look like. You might have an assembly for a lift head model.
Although I have owned both types in the past, i cannot remember if they are interchangeable, but I don't think they are...

This photo is from a US auction on Ebay and is going off soon for about $26USD. Might be able to switch out the rollers and make it work.

Kino · Aug 16, 2020

Roobarb said:
Ok thanks - I will.

I have been putting the rollers as far right as possible. Almost up to the red lid seal.

I am now running it with water just in the heated trough, not touching the rollers, and it is rotating much more evenly. I think part of the problem is that once in the water the rollers float and so become unstable. They can’t be fixed to the bottom of the unit at all. Is this normal?

Do you have an empty tank? It should have an equal amount of water in it that you would have for development for testing purposes or the tank will float!

Kino · Aug 16, 2020

Kino said:
View attachment 252452 No. That is why I think you might have an incorrect roller assembly. This is what it should look like. You might have an assembly for a lift head model.
Although I have owned both types in the past, i cannot remember if they are interchangeable, but I don't think they are...

This photo is from a US auction on Ebay and is going off soon for about $26USD. Might be able to switch out the rollers and make it work.

EDIT: on second thought, see if you can remove the rollers from the extensions and place them in the base itself without the extension arms.

Sirius Glass · Aug 16, 2020

Maybe the problem is the magnetic coupler. I suggest you get the direct connection to the top of the tank. I only use that method so I have no experience with the magnetic coupler.

mshchem · Aug 16, 2020

Two things to check that I've had to deal with.

The donut magnet on the machine can come loose from the plastic she'll and may need repair/replaced. The roller carrier should snap fit to the ridge of the trough. If the roller carrier is worn or cracked it won't stay firmly affixed.

mshchem · Aug 16, 2020

Plastic shell

grahamp · Aug 16, 2020

The magnet bases on the tanks are intended to be fit and forget. You can prise them off, but over time they will get loose if you do it too often.

There is a central ridge running down the center of the shelf in the water bath that should line up with the motor shaft. The roller mount actually clips onto that ridge.

I usually place the rollers around the point of balance for the tank. If you have the roller at either end, it will magnify any oscillation, and may work the magnet off the tank - see the first point.

mpirie · Aug 17, 2020

Is it safe to assume the magnet is fitted to the base of the tank correctly?

There are four small studs in the outside base of the tank to make sure the magnet doesn't slip. If the magnet on the tank wasn't fitted properly, this could cause an oscillation.

Mike

AgX · Aug 17, 2020

I do not see a misalignement. We should not overlook the position of the camera and its optical axis.
Much better would be a position with the optical axis
-) parallel to the center ridge
-) right above the ridge

Problem with Jobo CPE2+ Can anyone help?

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