Smooth focusing on an enlarger (Durst m601)?

Hello everyone. I have a Durst M601, which is perfect, except for the focusing mechanism. Which isn't very smooth to move. I've look under enlarger at the focusing mechanism, and seems to be able to move up and down via friction. Would some lubricant need to be applied? Any ideas?

There is a common arrangement that comprises two cylindrical rods with a small wheel that turns to provide the motion by friction. In this arrangement any unevenness on the rods or the wheel causes rough movement, such contamination might be likely in an older machine that has been in a darkroom where the chemical trays are left uncovered for long periods and the metal surfaces may have corroded. A remedy is to examine the rods and wheel carefully and remove any roughness and/or dirt on them, the use of mild abrasives may be appropriate, such as "scotchbrite" cleaning pads. Sometimes the rods are secured by a few screws and are easy to remove, this makes the process easier.

I think the enlarging lens manufacturers missed the mark when they left out the focusing helical for fine adjustments.

A suggestion for the OP - if you included "Durst M601" in the thread title, you might get more responses.

Get a good Durst, not a cheapie.

tedr1 said:

There is a common arrangement that comprises two cylindrical rods with a small wheel that turns to provide the motion by friction. In this arrangement any unevenness on the rods or the wheel causes rough movement, such contamination might be likely in an older machine that has been in a darkroom where the chemical trays are left uncovered for long periods and the metal surfaces may have corroded. A remedy is to examine the rods and wheel carefully and remove any roughness and/or dirt on them, the use of mild abrasives may be appropriate, such as "scotchbrite" cleaning pads. Sometimes the rods are secured by a few screws and are easy to remove, this makes the process easier.

Click to expand...

There is some rust on the metal rods. Maybe if I dip the rods into vinegar, would remedy it?

Re the rust, you could try a bit of fine steel wool.

chip j said:

Get a good Durst, not a cheapie.

Click to expand...

The M601 is a good one, you're just stirring the pot (again). I bought mine new in 1976, no complaints yet.

The enlarger is OLD.
The grease has probably dried and is STIFF, and possibly mixed with decades of dust making the dried grease even STIFFER.

I would CAREFULLY investigate the focusing mechanism to determine what moves and where the friction points are. Then determine where you can grease and more importantly where you should NOT grease. Some enlargers use friction focusing (vs. rack and pinion), so do NOT grease any place that is in contact with the friction focusing mechanism.

Then CLEAN the old grease off with rubbing alcohol or similar solvent. Be careful not to get the solvent onto any plastic parts, as some plastics do not like alcohol or solvents. If you can disassemble the mechanism you can clean it better, especially parts that side inside other parts. Just document it well, so that you can put it back together correctly.

Then grease where you should, with a THIN coating of grease. I use white lithium grease.

Rust is not good, the rods should be smooth and shiny. Use abrasives to make them smooth. Because the original plating has been damaged by rust the smoothing process may have to be repeated sometime because the base metal is no longer protected by the surface plating. Vinegar is a waste of time.

maybe i am thinking of a different enlarger, but
believe there is a metal ribon in the back that coils and uncoils
to counterbalance the enlarger make sure it is still there ..
clean and then use a light bit of lithium grease or something similar
to help it go up and down. i have the same enlarger, but have never
had to do what i suggest you do ,, good luck !

The M601 is my favorite enlarger, it is sturdy and easy to use. The friction system of the focus is quite easy to care about. Follow the instructions of thread #9, that`s what I did with several Durst M301. . I wouldn`t replace my M601 with any other enlarger ....

Can break lubricant be used?

mehguy said:

Can break lubricant be used?

Click to expand...

Brake lubricant, if you mean the high temp silicone grease used for pivots in disc brakes, could be used but might be a bit of overkill for this application. White lithium grease would be fine. Omega used to recommend Vaseline.

darkroommike said:

Brake lubricant, if you mean the high temp silicone grease used for pivots in disc brakes, could be used but might be a bit of overkill for this application. White lithium grease would be fine. Omega used to recommend Vaseline.

Click to expand...

Well, the brake lubricant is all I had at the moment, but seems to work well now. Although, it's not as smooth as I'd like it, getting to the area where the knob comes into contact with the steel bars was a B*tch to reassemble, so no way I'm going to back and regreasing it haha.