Hasselblad 500 Issues with mirror and crank

[john_booz]

<p>I have an old Hasselblad 500 CM camera that I have not used for a number of years and was going to sell<br>

to someone. I tested it out using the shutter speeds matched with the various Fstops. When my buyer<br>

tried the camera the mirror began to stick in the up position on about every 10th shot. <br>

I have since tried the camera, and as long as I am cranking the rewind cylinder crank gently the mirror<br>

works OK. The more I have tried the shutter by shooting off shots the more frequently the mirror has <br>

stuck in the up position. If I rewind the the camera gently to the 1st red dot on the rewind crankcase all<br>

is OK. But it is in the final small cranking between the 1st and 2nd (final position) red dot on the crankcase,<br>

that the problem occurs. Do you have any advice as to what is occuring?</p>

[Robin Smith]

<p>Not really: it just needs a good CLA.</p>

[john_booz]

<p>Maybe I described the problem poorly. The problem is now: when doing the rewinding to set<br>

the shutter and mirror - the shutter cocks, and the mirror is in the down position and ready until<br>

the first red dot on the Rewind crankcase. But when you wind the crank the final fraction of it's<br>

total distance (ie the last small crank from the 1st red dot to the final fully cranked position,<br>

(which is the second dot), the mirror raises up without activating it with the shutter. <br>

So the mirror actually goes up before it should. It seems to work fine without the lens<br>

mounted. Hope someone has some advice for me. Thanks John</p>

[henry_finley1]

<p>I recognize this problem. There is a small spring made of wire the diameter of a hair that has gotten mangled. This spring actuates a little bitty "finger" on a gear underneath the bigger gear in the upper right hand corner of the chassis. What happens is that the spring comes unhooked and sticks out, which causes it to get mangled in the winding stroke. It only takes that once, and the spring is toast, and the problem will never go away. Your camera is for all intents and purposes incapacitated until someone goes in, corrects the problem, and gives the chassis a good CLA and repair.</p>

[john_booz]

<p>Henry thanks for your help. I have another question you may be able to answer. <br>

When I take the lens and film back off the body - and crank the rewind completely, the mirror<br>

drops to the down position and doesn't raise up prematurely. It functions until the shutter button<br>

is pushed in the normal manner. Furthermore I can crank off shot after shot and the mirrror<br>

works as it is expected to (ie not raising up early). Shouldn't the mirror raise early regardless<br>

of the lens and back being on or off? Let me know what you think, Thanks, John B</p>

[henry_finley1]

<p>I don't know. I have never heard of this. You are saying (I believe) that the body works correctly without the lens and back, which tells me my previous diagnosis may be faulty. I would have to open up the body and observe the action to pin down this problem. Remove the back and the lens one at a time and observe the action, then alternate and observe again. This may be a maladjustment of the mirror catch-pawl and nothing else. If so, the lens may be the contributing factor, if it has gotten stiff and dried out. Or the catch-pawl mechanism may have become worn. The catch-pawl is on a splined shaft, and I have seen the splining come loose, allowing the shaft to wobble, and work intermittently. At any rate, without attention, this problem will get worse pretty quickly.<br>

Trip the camera to get the mirror up and reach in and wiggle the mirror catch pawl finger. If it is wobbly, then the shaft splining has come loose. There may be some small amount of wiggle, but if you get the feeling it is really loose, you'll know by instinct.</p>

[douglas_fairbank]

I think the problem you have is that the mirror lever needs adjustment. The movement of the mirror is not quite enough to

engage the latch.

[henry_finley1]

<p>Actually Mr. Fairbank--you're right, of course. Because I had to make that adjustment once. But since I'm not an authorized tech like you or Mr. Odess, I don't have the tools and training to do that like you guys might be able to do. I had to disassemble the chassis to get that angled cam-to-mirror lever out of the camera and bend it by trial and error, till the mirror came down enough below the catch-pawl till the pawl could get a grab on it. You really have to be careful putting it back together so that the hairpin spring doesn't get trapped under the central part of that lever. There really is no adjustment of the catch pawl itself like I stated it. I was only simplifying.<br /> But no matter which of these problems the OP has, somebody is going to have to open up that body and do some work to it, because this problem doesn't "go away".</p>

[john_booz]

<p>Dear Henry Finley and Douglas Fairbank, I am very grateful for you guys responding to my questions about my Hasselblad 500 CM with the mirror problem ( ie the mirror raises before the final crank of the rewind crank). This is my 1st time blogging so I am very happy to see you took the time to respond.<br>

Like my last comment stated: the mirror works normally when the lens and back are off: it stays down until the crank is fully wound and it raises when the shutter button is pushed. The time it raises is when the lens is mounted. Having tried and watched the action many times, I also thought there must be a latch not engaging. I think it is directly in the middle of the lens mount hole, and under the screw that engages with the lens to crank the lens shutter. I have seen Hasselblad Repair Manuals on EBAY for about $20 and I think I could fix the mirror if I have something (ie the repair manual) to refer to for the minute screws, etc. Do you think this is a good way to go, and once again I cannot see any other reason that the mirror would function correctly without the lens and body mounted? Thanks again, John B</p>

[john_booz]

<p>Dear Henry and Douglas Fairbank, Again I probably described my problem bad, and a better question would be: When looking thru the camera from the rear(without the lens and film back), I can see the rotating shaft that appears to go from the actual shutter button ( on the front left) to the rewind screw on the camera that engages with the screw on the back of the lens to rewind the lens shutter and aperature. I dont think this is where the mirror lever latch is and am asking is the mirror lever latch that may need adjusting actually at the rear of the camera where the mirror is actually mounted and rotates up from? If so then I need to remove the interior body of the camera from the outer shell... correct? Thanks for your help, John B</p>

[henry_finley1]

<p>You do not exhibit understanding of how the camera operates from what I'm reading. (not to be insulting). The mirror catch is actually not adjustable. Under the interior sheet metal cover is a cam that moves a lever extending to the axle area of the mirror. This lever requires removal and bending to force the mirror to go lower than the mirror catch, so that the catch can get over the lower corner of the mirror and get a grab on it. But that is not necessarily at all the sole cause of your problem. Believe me, this is actually a simplistic camera in many ways compared to the 2000 parts in a Nikon F2, for instance. But the inter-relationship of the operation of the parts can make problems elusive to solve. Further, it sounds as there are one or more worn parts that cannot be compensated for. Translated: this is not a job for the owner. Further, even if you do successfully fix your problem, it is likely that you will get body-length tolerances fouled up upon reassembly, causing focus errors. On top of that, there are foam pads under the mirror that invariably need replacing while the camera is disassembled. And there are lubrication issues that need to be addressed while the camera is opened. If not addressed, it's only a matter of time before the very problem you are having, returns, with the resultant destruction of parts. This camera needs a professional (or at least highly learned) CLA.<br /> I am NOT in any way a trained tech, but a guy who spent many many hours ready, studying, and experimenting until I became proficient in body issues. MANY hours. I highly advise you do not attempt this repair. Reassembly without knowing the technique may result in an apparently working camera for however long, but it will be nothing more than a box camera in the photographic results it delivers.</p>

[henry_finley1]

<p>Too much time has passed and I can't edit the above: reading, studying, and experimenting.</p>

[john_booz]

<p>Dear Henry, I got nothing but time as the old adage goes, so I am interested in learning about how the Hasselblad works. As I stated, there are Hasselblad Repair Manuals for the 500 c/m for sale on EBay. I did find and watch a video someone posted about removing the interior from the exterior shell, so that helps one to get going. I did notice the plate you mention up at the area of the camera where the shaft that rotates the mirror would go.<br>

I appreciate your help and will probably get the manual and see what I can do. I was merely asking if anyone had knowledge of this problem - which you did. However you stated that the way you did the repair was probably different from the way a real "tech" would do it. We'll see what happens and I'll stay in touch with you. John</p>

[henry_finley1]

<p>OK. You sound bound and determined. But let me give you a heads up and fair warning about something. In the upper left hand corner of the chassis is the gear that turns the gear on the film back, that winds the film. That gear has a coiled spring inside. If you remove the screw and take off the little cover, and let that coiled spring get out, it's all over--you're cooked. You'll never get that spring back in and will only end up destroying it trying. That spring will need to be cleaned and lubed. Good luck with that--you'll need it.<br>

In closing, you need to be prepared for kissing this camera body goodbye. And so far as getting the chassis back in the shell, good luck with that. BTW--the magic number is 71.40mm. You'll need to fabricate a jig and have a known accurate dial caliper, at the least.</p>