Focusing the Durst Laborator 54

[Yourix]

Hi there !

I'm a bit confused... I'm setting up a new darkroom after almost 20 years since my last wet print. I stored my enlarger all this time, knowing one day it was going to be used again, and I'm happy I did.
It is a very nice Durst LABORATOR 54 with no components missing and in very good shape. I used to do very nice prints with this little beast.

But i can't remember how to focus !
It can sound silly as it is usually pretty straightforward on most enlargers but this one is a bit special. It is a production tool, designed to print billions of pictures with as little effort as possible, and it has a mechanical autofocus system calibrated to work with a 150mm and only a 150mm. With any other focal length you have to focus manually.
But I don't find any knob to fine-tune the focal-plane/film-plane distance (aka "focusing knob") and can't remember at all how I was doing it in the good old times .

I have a pdf of the user manual but pages 10-11 are missing and they are precisely the one where they show how to manual focus.
The lens are mounted on a helical barrel that can do the job I guess but it doesn't ring a bell and I'm pretty sure there is an other way to do it.

Is there a user of this enlarger here ?

[ic-racer]

Can you post a picture of the enlarger.

I'm guessing, is it this Durst 54? Knob 15?

[MartyNL]

Think some pic's of your enlarger would be helpful.

'Knob 15' and 'scale 29' looks similar to my L900 (which also has a mechanical "auto focus" feature) and this part is used specifically to adjust for differences in printing easel to baseboard distances/thicknesses.

[Yourix]

Yes it is this exact enlarger.
The second picture you post is one of those missing in my pdf. I'm pretty sure focusing is achieved with knob 18... But it doesn't work on mine.
So maybe something is gummed after 20 years of storage and i'll have to check that. It is a bit surprising because all others knobs and features are working as they are supposed to do...

[MartyNL]

'Knob 18' would be (one of) the most logical to adjust the focus.
There may be a lock/brake on your knob 18, to avoid focus drift/creep OR some kind of tension adjusters in and around your lens stage moving parts.
Gummed up lube may be the culprit but I would still expect some kind of movement without applying too much force.

I'm unfamiliar with your Durst model but as you know, they tend to be very solid and well thought out machines!