Durst Mivalo punch repair

[Andrea Gazzoni]

So I recently noticed an issue with my registration punch.
The punch is a Durst Mivalo, it makes a line of 1.5mm holes in the film edge, spaced, from the left hole, at 19, 32, 51, 76.5, 102, 127.5, 153, 178.5, and 204mm.

I noticed that especially with larger negatives on thick polyester base the punch misses the two center holes. You can see a faint sign of pressure but no hole there. The other holes are ok. The missing holes are in on 4x5 and larger negatives. Not a real issue on 8x10, but on 4x5 and 5x7 you are missing the holes that are where the pins in the carriers are.

After a bit of trial I had it back to punching the center holes by putting sort of a cardboard shim between the center area of the pin bar and the pressure bar attached to the handle.

At first sight it works now, all the holes are perforated, but I notice that the center holes are not as clean as the others but are surrounded by what looks like cracks in the film surface.
Cracks are clearly related to the shim, as they get worse going from left area (no shim) towards right (shimmed area).

Do you think the cracks around the holes are caused by lack or excess of pressure? Do I need to somehow sharpen the pins? I tried the folded tinfoil workaround to no avail.

Also, I don't see any apparent deformation neither in the pin bar nor in the pressure bar, so I'm not sure what caused the missing holes. Do I risk damaging something by putting a shim as I did?

I know not many of these are still being used, so this is probably a long shot
thanks
Andrea

[Conrad . Marvin]

I am not familiar with this particular punch, but I can tell you that ( call the pin a punch and call the hole in the plate under it a die) if either the punch or the die has been warn or bent then a clean hole will not happen. I can’t quite tell from the pictures how the whole system works, but you might have to replace the pins or the plate or both to get a clean hole or set of holes in a negative. The fact that the hole in the negative does not have clean edges is suspect. It may be possible to resurface the plate and sharpen the pins so that they come down into the holes in the plate at the same time. But then again you may be rebuilding the whole punch set up.

[Tin Can]

You are in Milan!

Find a Tool & Die maker and buy him/her a drink or 6

I used to weld up cracked worn dies for our Die person to regrind

Everybody doing this type of work is bored and well paid

Bring a print, look around the back for smokers

[Conrad . Marvin]

Sounds like a plan.

[Drew Wiley]

Take your magnifying loupe and see if certain punch pins are dull or uneven on the end. Milvalo punches are now quite rare, and probably most won't be in great shape by now. Inserting shims might not be wise. But the ideal solution has already been given by Tin Can.

[Andrea Gazzoni]

Thank you for your suggestions. I am trying to locate a company in my area that wants to repair it. Not easy.
I quickly removed the shim in fear of causing damage.

[Bob Salomon]

Thank you for your suggestions. I am trying to locate a company in my area that wants to repair it. Not easy.
I quickly removed the shim in fear of causing damage.

Why not check companies in Bolzano?

[Andrea Gazzoni]

Bolzano is not offering support of any kind on their analog products since 10 years at least...if that's what you mean. No spare parts, no documentation, no repair.

[Tin Can]

Few Die makers want a small outside repair, actually none, they are busy

That's why you need to smooze them on smoke break

Here in Milwaukee and Chicago, Die Shops break away from big factories as they can make more doing custom work in their own little shop. Often they get fed a lot of work from the factory they left!

These shops make a lot of boring money

Carry a portfolio, be not too friendly, get them interested

I have a lot of schmoozing experience from huge factory work, tool sales and walking up to a strange shop and talking them into a tiny job or buying my widget of the day

Start asking people how do I get this fixed, somebody will know

another somebody could make a new one


Thank you for your suggestions. I am trying to locate a company in my area that wants to repair it. Not easy.
I quickly removed the shim in fear of causing damage.

[Bob Salomon]

Bolzano is not offering support of any kind on their analog products since 10 years at least...if that's what you mean. No spare parts, no documentation, no repair.

But there may be some machinists there that no longer work for Durst but do know your punch.

[Drew Wiley]

Any competent machinist could do it. You don't need a diemaker or someone with Durst background. But it might be simpler just to start over with a completely new punch and identically matching pin bar. Ideally, these are made at the same time. Otherwise, it's helpful to have a punched master reference on either dimensionally stable polyester film base (not acetate) or brass shim stock. Tolerances need to be very tight on this kind of gear.