Durst Laborator L1200 problem with roller bearing of the column

I have problem with my Durst L1200. While moving head up and down I hear and feel clatter. I'm suspect that something is wrong with one of roller bearing of the column. There are marks on the colmun one the one side which indicate that roller can be jagged.
I'm guessing to check what is going on I need to dissasamble spring from the column. I know this part can be tricky and I want be sure that I will be able to assamble back. Is here anyone who had either similar problem or had to disassamble spring in this enlarger?

Hi Mikolaj,

I haven't had the same problem as you, but I recently dismantled my L1200 to replace the rack and pinion which had become damaged over years of use. I didn't remove the spring; I simply disconnected the anchoring plate at the top of the column, leaving the coiled spring attached to the back of the carriage assembly. I'm sure you realise the power in the coiled spring, since you've dismantled the unit thus far. I'd say you should be able to replace any of the rollers without doing anything further with the spring. Are you sure it's a roller? Damaged rack and pinion can cause rough travel. I would imagine that if it is a bad roller the roller will feel rough when rotated by finger. If it's rack and pinion, look for missing or damaged teeth. Good luck.

Barry Kirsten said:

I'd say you should be able to replace any of the rollers without doing anything further with the spring.

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This is interesting, as Durst advised to remove the springs to push up the complete enlarger head off from the top of the collumn to get access to those rollers.

Hi Barry,
I haven't started yet. I used picture form the internet as example to show where I have issue. Did you have any problem to screw it back on to the anchoring plate with spring to the top of the column? Did you have to use high force, or any aditional tools?

I'm sure about roller. There are even spaced marks on the column made by roller suggested that one of them can be chipped. I hear knocking and feel vibration during movement.

Ahh, I understand now. So, to start with a word of caution: The roll spring is VERY powerful. I learnt the hard way when I purchased my L1200s (I have two of them) and pulled them down for thorough cleaning. I made the mistake of removing the head with the carriage about half way on the column. Then I released the lock and the carriage shot up to the top - like a rocket - since there was less mass to be counterbalanced. I had a couple of fingers in the way and one was severely crushed! It recovered, but a painful lesson was learned.

When I replaced the rack and pinion recently I first removed the head then carefully raised the carriage to the very top of the column. You have to be strong to hold against the power of the spring to allow this to happen in a controlled way. With the carriage at the top it's possible to remove the four screws that anchor the spring to the top of the column. I left the spring assembly attached at the rear of the carriage. You need a lot of strength reattaching the spring at the top when re-assembling it as you have to hold it in alignment and simultaneously put the screws in. But it's do-able.

With the spring detached at the top, the carriage can be slid off the column, allowing access to the rollers and the locking mechanisms etc. I'd check before you start to ensure that you can get a replacement roller. I believe Durst parts are hard to come by now. Good luck with it.

In the worst case one would have to take the plastic ring off the bearing, have a new ring machined and to press it on again.

Mikolaj​

Mikolaj said:

Hi Barry,
I haven't started yet. I used picture form the internet as example to show where I have issue. Did you have any problem to screw it back on to the anchoring plate with spring to the top of the column? Did you have to use high force, or any aditional tools?

I'm sure about roller. There are even spaced marks on the column made by roller suggested that one of them can be chipped. I hear knocking and feel vibration during movement.

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Hi Mikokaj,

Did you make it?

I once changes the pinion without removing the spring.

The only thing I have made it lift the head at maybe 12'' from the very top. I did put a piece of wood between the head and the stopper on top and another one between the base and the lower part of the head. I taped the pieces of wood against the column to make sure they didn't move and then I made the pinion replacement.

A couple year ago, I did replace the spring and the sheer force of it and the hard time it did take me made me think of another way going around the problem...

Hope this helps if you haven't done it yet.

Hi Andrel,
Yes I did, but another way around... Due to lack of time I just bought a new column. So now I have two. The old one is taller but it's okey. I don't make big prints. I going to fix old one and maybe I will try buy parts to bild a another L1200
Thank you for advise.

When the spring went in my L1000 I rigged up a simple counter weighted pully system. Been using it for a few years now.