An issue with my Durst L138

[francis90]

Hello,

I have a Durst Laborator L138s which has a slight problem, I wonder if anyone can offer some advice on fixing it.

The baseboard which is on a carrying arm (and which is able to move up and down by twisting a knob and pressing down on a foot-pedal) moves slightly from left to right when it should actually be locked in place. This can be an issue since it doesn't take much pressure in order to move it. I'm thinking that something needs tightening, but I'm not sure what.

Any advice would be much appreciated.

Thanks for your time,

Francis

 

[AgX]

There is that feature of a swivelling baseboard to facilitate perspective distorsions or rather the appropriate countermeasures.

There is a means to arrest the board in neutral position, by turning up two arresting bolts. Maybe that mechanism is out of alignment. I assume these bolts can be adjusted in height.

 

[bluejeh]

Durst 138

Francis,
AgX is correct, there are two handles immediately beneath the baseboard that you turn upwards to stabilize the table. We only discovered this two years after we started using the enlarger!

 

[L Gebhardt]

Does the arm move, or just the baseboard? If it's just the baseboard rocking then the answer is to swing the handles up until they lock touch the baseboard. if the arm is shifting I don't know how to adjust that. The arm on mine can be pushed and it rotates a degree to two around the column. I've been trying to get this locked down on my enlarger.

 

[DREW WILEY]

There are locks and adjustments for everything, but I have seen certain of these features worn out on very heavily used old enlargers. A bit
of the problem answering is that the 138 series was made over several decades, and not all of them are exactly the same. With my units there are adjustment screws on each side; but due to the age of one of my 138's (which I originally bought for spare parts and later refurbished into another fully workable unit), I had to turn the front locking knob rather aggressively tight to avoid the problem you describe. ... it annoyed me
and I eventually found unused parts for a true cure. You really gotta inspect everything and look for signs of excessive wear and tear.

 

[DREW WILEY]

What Larry mentions is different from what I just described. There are adj screws for column play too, though you shouldn't overtighten them
and create friction. But the long graduated rectangular piece running vertically on the lower column can sometimes develop sloppiness too if
the basic attachment screws are loose - which is an easy fix just by tightening them. You should try to get ahold of a basic maint manual for
the machine.

 

[bluejeh]

Durst L138S Enlarger

I have two different manuals (pdfs) for that enlarger if you need them.

 

[francis90]

Thanks for the replies!

The problem I was describing is what Larry mentions, it seems that the whole carrying arm moves slightly. Also I have found that tightening the largest locking screw with some force can help somewhat, but that is not ideal. It is an old piece of equipment, it probably could do with stripping down and cleaning.

I think also what Drew mentions is related, that is if I am right in thinking that Drew is describing the guide rail that is attached to the main column, it does appear to move slightly when the baseboard moves as I have described. However, it seems that the screws which attach it to the column are not adjustable since there is apparently no screw head (just a flat piece, rather like the bottom of a flat screw) which is odd, I will have to have another look when I get home tomorrow.

Agx, I am glad you have drawn my attention to those bolts underneath the baseboard, I do think they are adjustable now that I think about it which is handy because the board is slightly out of alignment, to compensate so far I have been rather crudely shimmying the easel with paper, but now I can sort it out correctly.

bluejeh, that is very kind, do you have the service manual by any chance?

Thanks for all your help,

Francis

 

[L Gebhardt]

Thanks for the replies!

The problem I was describing is what Larry mentions, it seems that the whole carrying arm moves slightly. Also I have found that tightening the largest locking screw with some force can help somewhat, but that is not ideal. It is an old piece of equipment, it probably could do with stripping down and cleaning.

I think also what Drew mentions is related, that is if I am right in thinking that Drew is describing the guide rail that is attached to the main column, it does appear to move slightly when the baseboard moves as I have described. However, it seems that the screws which attach it to the column are not adjustable since there is apparently no screw head (just a flat piece, rather like the bottom of a flat screw) which is odd, I will have to have another look when I get home tomorrow.

Agx, I am glad you have drawn my attention to those bolts underneath the baseboard, I do think they are adjustable now that I think about it which is handy because the board is slightly out of alignment, to compensate so far I have been rather crudely shimmying the easel with paper, but now I can sort it out correctly.

bluejeh, that is very kind, do you have the service manual by any chance?

Thanks for all your help,

Francis

The screw heads are inside the column, access through holes in the back of the column.

I have a scan of the service manual up at http://www.trippingthroughthedark.com/durst-laborator-138s-manuals/ I don't think this covers how to fix the issue you are having. The more I look at the service manual the more I think I'm missing some pages.

 

[DREW WILEY]

As I recall, you have to access the screws tightening the vertical strip from the opposite side of the column. There should be access holes
directly opposite each one, though I can't remember the screwdriver size. I should have a full manual somewhere, but it might be hopelessly
buried in stacks of ancient literature. You might be able to download a copy from the Jensen Optical website (Durst Pro USA). It also helps to
clean and lube the big feed screw connected to the locking knob in front of the baseboard. Basically, you might need to inspect all the interconnected mechanical components. But a good tuneup should last a long time.