Durst M70 VC head - questions to the owners

[kal800]

Hi, it seems I have a problem with my VC head. I noticed that I'm having inconsistent results - especially during callibration of darkroom analyser.

Now, when I looked closely to the head, I saw, that filter placement is not always the same, it changes when I turn the dial from G0 to G5, or switching in and out lever back and forth or in different occasions when I can't determine.

Have a question to anybody who owns that VC head - when looking through the square filter window in one case I've got current layout:

G0 - 30% White (no filter) , 40% Y, 30% YM
G3 - 50% W, 50% YM
G5 - 50% M, 50% YM

Could you tell how filters behave in correct VC head?

From what I saw in Ilford docs the colour should range from full Magenta (G5) till full Yellow (G0), so turning the contrast dial should result in more or less gradual movement of both filters in opposite directions covering full window each time. It is not in my case for sure.

Any feedback much appreciated.

Kal

 

[kal800]

Hi,

Have a root cause. More to that - the solution itself is really straightforward but have a serious showstopper and I really hope that I will get some serious advice here, otherwise my gear seems out of order and photography art shall suffer ).

Have a look at the photo. Two plastic gears are responsible for controlling Yellow and Magenta filters. They are rotated by the same gear which is connected to the grade changing knob. Now, filter are being moved using followers that are moved by two alloy cams. The cams are glued to the plastic gears, and here we've got a problem. The glue on Y cam worn out so the cam could move regardless of the gear to which it should be sticked, which caused my inconsistencies.

The solution is simple - glue it back, but it turned out that it is not that easy. As you can see on the picture, the plastic gear has some inner shape perfectly matching alloy cam, but it was originally glued on the other side, so in that case that shapes do not match anymore.

At the beginning it just came to my mind that the same problem occurred before and somebody was trying to fix it, but flipped the sides, which seems unlikely because there is letter "Y" engraved on the front side of the cam in the same manner as on the other - Magenta - set. Besides if somebody didn't know which side to choose, he would rather use matching pattern. Also, as you can see on the close-up of the cam, there are some markings around the holes meaning that this is clearly front side of it.

There are couple of holes on both parts which are probably being used for aligning purposes - there are three different possibilities, but I do not have a clue which one should I choose, and I would not like certainly to go for a trial and error approach.

If ANYBODY possess that thing, I would like to ask for a tiny favor. Please remove the front case of the Vario module (don't worry, it is meant to be opened by user to change the battery inside), and shoot me the same photo as I'm attaching. It will solve my problem within moments

Thanks in advance.


Kal

 

[kal800]

Actually there is an easier solution. Turn the knob for the lowest possible filter setting (tiny bit below G0 when you cannot turn it anymore) and make a photo of the front of the device - where the current grade is indicated.

 

[ic-racer]

I dont see how it could possibly work with the cam on backward

 

[John Koehrer]

When you do figure the position, use a contact cement never seen one dry out and they don't get brittle.