Servicing your own Hasselblad A12 backs

[ymc226]

Now that these backs are so cheap, has anyone taken one apart to service it themselves. Specifically, does anyone know how to adjust the spacing between frames?

I'm cheap and want instant gratification so I want to fix it myself and not have to wait or risk losing it in the mail. There will always be risk in terms of me messing something up but I'm willing to take that risk.

I've changed the light seals and have taken the gears apart to oil the parts underneath and put it back together and it still works but is much smoother.

 

[epatsellis]

The nylon stop on the wind gear determines the spacing from what I can determine from online sources, do you have the service manual? A lot of your questions could be easily answered.

 

[Q.G.]

Solving spacing issues is a matter of having everything assembled and working properly (tightening loose screws and making sure moving parts can move freely will solve most spacing problems). And that nylon stop should indeed be intact (it gets dented over time).
Spacing itself is hard-wired: a pawl will drop into a notch on a meternig gear. There is not much that can go wrong with that. Should there be anything wrong with that part of the mechanism, it makes itself known by spacing problems between frame 1 and 2, and those two frames only.

So provided the nylon stop is still o.k., solving spacing issues will need no more than cleaning and reassembling the mechanism.

 

[Dan Henderson]

Should there be anything wrong with that part of the mechanism, it makes itself known by spacing problems between frame 1 and 2, and those two frames only.

I recently had a quite different experience with my A12 back. It began spacing erratically, sometimes slightly overlapping frames, sometimes spacing way too widely. And all through the roll, not just at frames 1 and 2. I love my Hasselblad gear, but all of that interconnected gearing and interlocking completely dissuades me from tinkering with it. I just take it to Peter, and pay him whatever he wants when it is fixed.

 

[Q.G.]

That sort of behaviour can be due to the nylon stop and/or a gummed up or loose mechanism.
It's always a good idea to have something fixed by someone who knows what to do, yes.

But for the OP, having a manual (original, or the short one produced by Dick Werner) and a magazine to take apart and play with, plus some time to do just that, will make you expert enough (in very little time) not to mess things up.
The only real problem is getting spare parts when you need any.

 

[Len Robertson]

The only real problem is getting spare parts when you need any.

Q.G. - You seem to be implying Hasselblad US won't sell repair parts to DIY repair people? Or am I misunderstanding?

Len

 

[ymc226]

I've followed on the usual auction site, prices for very used A12 backs and they are quite low. If fact, low enough to buy for spare parts. I have a couple of A24 backs in great condition that I plan on modifying into A12s using these "beater" A12s as donors.

 

[dnk512]

I bought A12 seal kit from Hasselblad directly. Shipping was more expensive than the part it self, so I bought 2 kits. They even helped me with the part number over the phone.

 

[epatsellis]

My experience has been that the DIYer's money is just as green, especially for common parts like seals. For smaller, less common parts, if you have the part number they'll just take the order and ship. The last thing you want to do is have to wast an hour of the guys time on a $10 or $15 order.

If only Sinar would learn the lesson, it took me 5 months (and an email to the CEO of Sinar-Bron) to order a $20 part for my 8x10P, and they didn't even have a parts manual on hand!

 

[Len Robertson]

I'm impressed with the positive tone of this thread. When ymc226 first posted his question, I fully expected a number of "Leave it to trained professionals" comments. That may be good advice, but not much fun for those of us who love to learn how things work, and get a feeling of accomplishment from repairing equipment.

I'm a perpetual bottom-feeder on eBay, and have ended up with a few backs with counter problems. I suspect most just need clean and lube. The only one I have opened up is a non-A 12 in beautiful condition which has a bad gear on the counter. I have a couple of other 12 backs I can probably get a gear from. However, even though both are in bad cosmetic condition and missing the peephole door (gaffers tape over the hole works fine), they still work just great. Whenever I buy a "parts" back, it turns out to be usable.

Does anyone have a recent approx. price on the seal kits from Hasselblad, including shipping? So far, I've used the $13 eBay seal kits. Maybe the genuine Hasselblad version is superior, maybe no real difference.

Len

 

[Theo43]

I intend to clean and lube my film backs when I install new light seals. It would be useful to have a step by step guide to avoid doing things wrongly, but $50 for such a guide seems, well, a bit much. Could we prevail on our friends at Hasselblad Historical to post something along the lines of the excellent light seal replacement guide? http://www.hasselbladhistorical.eu/HT/HTSeal.aspx Perhaps there are territorial issues involved.
Ted

 

[Len Robertson]

Ted - I agree it would be nice if there was an online how-to on C&L Hass. backs, or even a reasonably priced print version available. I understand the fellow who sells the $50 booklet has many years of experience and is selling his hard won knowledge, but $50? It seems to me if the price were half that, he would sell more than twice the number of copies and make more money, but that is his business decision to make. Producing an online guide will involve finding someone with the Hasselblad knowledge (and willing to give it away) who can describe the steps needed in the C&L, and the computer skills to put it up online.
I've spent a fair amount of time the last couple of afternoons tearing apart the wind/counter mechanism of my non-auto 12 back. I have the factory pages for an A12 to help me, skimpy as they are. The 12 and A12 backs are more similar than I would have thought. I'm trying to understand the function of all the little bits and pieces, and how they work together. I don't have the sort of logical mind to grasp things like this quickly, so I'm having to go over and over it. It is kind of fun in a frustrating sort of way. If nothing else, I suspect I'll learn that paying someone $80 to C&L a back isn't a bad deal at all!

Len

 

[Sirius Glass]

I paid $75 for cleaning and adjusting a really gummed up back. The rest of the time he as made minor adjustments and cleans of several backs at no charge. Therefore, when he said $75, I said thank you.

Steve

 

[Len Robertson]

I found an online version of the Hasselblad back service manual:
Dead Link Removed
I've been able to tear down my non-auto 12 back, using the A12 manual and a bit of thought. If anyone is removing the mechanism cover from a 12 back, the procedure is very different than that for the A12. I'll post how to get into a 12, if anyone needs the info.
The next step is finding suitable grease. The Isoflex Topas L 32 grease recommended in the manual seems to be a Kluber product: http://www.klubersolutions.com/pdfs/Isoflex Topas L 32.pdf In the Kluber product line it is listed as a low temp grease. The smallest quantity seems to be a 370g cartridge. I can't find a price online, but I see references to Kluber specialty greases being expensive. On one industrial forum, a different Kluber grease was mentioned costing $100 for a cartridge. Maybe the Topas L 32 isn't as expensive. Microtools has Rheolube Dead Link Removed that has a similar temp range, and may be "sticky" enough it won't migrate off the parts. Or maybe someone has a better idea. There are a few photonet posts on Hass lubes, but none saying "Grease X" is a wonderful, cheap substitute for Topas L 32.

Len

 

[Q.G.]

Len,

There are indeed "territorial issues" (as Ted called them); copyright prevents just putting up a manual found elsewhere.
But if you can write up the steps involved, add a number of pictures too, i'd be more than happy to put it up on the Hasselblad Historical site!

(The site is a community thing, and everyone can submit things for publication.
As long as it fits the site's purpose, and is good enough, of course.
But apart from a by-line, don't expect anything in return. It's a labour of love, and like anything involving love, only costs money... )

 

[Theo43]

Len,
Geez, that service manual is intimating! As to grease, consider 'white lithium grease', used for lubing fishing reels, and gear trains in model RR locomotives. You can get this anywhere fishing gear is sold and it is not expensive. The trick with any lube is to apply sparingly; investigate the properties beforehand as I have no idea if it is good for this application. Happy New Year!
Ted

 

[Q.G.]

Cleaning the mechanism is more important than getting exactly the right grease to lubricate it.
Once you know how to, it is not hard to service your magazines as often as you like (once a year sounds about right. It doesn't take long.)
So if you can't get the right lube, you can make up for that by servicing the magazine more often.

 

[Len Robertson]

Q.G. - As I'm learning to service backs, I'll keep in mind putting something up online. However, I feel I need a lot more experience before I try to do so. I've yet to get inside an A12, and I suspect there is more interest in A12 backs than the older non-auto version.
Ted - I was thinking of white lith grease as a possibility. I even have a tube somewhere, although it is several years old. I should probably get a fresh tube.The lith grease I've seen seems sticky enough to stay where it is put. I don't know how much it thickens at lower temp, although if it is very cold, my cameras and I stay inside. Some of the places grease is used in a Hass back are arms that must return by spring tension. It is possible some greases may thicken enough in just cool weather to be a problem. I have another couple of months of winter ahead here, so I can do cold weather testing.
This is where an amateur hacker has an advantage. A professional repair person must use lubes good in temperature extremes, since he doesn't know how the equipment will be used. He doesn't want any returns which cost him both time and reputation. I, on the other hand, can mess about as much as I want. If I do something wrong, I don't have far to look to find the who is at fault.
Ted, that factory manual takes some getting used to. I was a bit surprised to find the section on disassembly of the A12 back mechanism is only about a half page. It doesn't seem enough information for something so complex. However, after studying the exploded view and reading the text several times, I realized all the information needed is there. I wrote the number from the exploded view beside each part number in the text. That made understanding the disassembly instructions easier to follow when looking at the exploded view.

Len