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10-09-2017, 01:00 AM   #1
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HELP Pentax 645 winding issue

HI guys, I am a long time reader but my first post here and I am asking for help already solving a mystery that has me stumped.... I asked this on other forums but feel this may be a better place to start

My Pentax 645 is struggling to wind the film towards the end of the roll. I have scoured the internet to find an answer and so far drawn a blank. I initially thought it was chewing through batteries but actually they are fine, and it seems to be a film issue.

---------- Post added 10-09-17 at 01:01 AM ----------

QuoteOriginally posted by Thenorthernmonkey Quote
HI guys, I am a long time reader but my first post here and I am asking for help already solving a mystery that has me stumped.... I asked this on other forums but feel this may be a better place to start

My Pentax 645 is struggling to wind the film towards the end of the roll. I have scoured the internet to find an answer and so far drawn a blank. I initially thought it was chewing through batteries but actually they are fine, and it seems to be a film issue.
Dry firing with the back off it performs perfectly, first maybe 5 or so shots off the roll it performs perfectly.

As you go through the roll it seems to struggle progressively more and more to wind the film, until the last few shots it can't even manage to wind a single frame and you have to flick it off and on again to coax it through bit by bit.

It does the same no matter what film you use, and it is the original factory 120 back with 120 film.

I sacrificed an old film, loaded it into the camera and wound it through manually, I found there is quite a lot of resistance, and the further through the roll you get, the tighter the film and more resistance there is, until eventually it is difficult to wind the film manually towards the end of the roll.

Pretty sure it is an issue with the holder and something is not as free as it should be. The end spool (with the big metal cog) seems to spin relatively freely. The start spool is quite stiff and tight to turn and there is some resistance. I undid the 3 tiny screws to take off the plate at the side of the film holder to see if there was anything obvious under it but there isn't and everything looks like I guess it should.

Anyone else had this issue?
Could anyone check for me to see how much resistance there is turning the film on the first spool?
Could it be the way I am loading the film (pretty sure I am loading properly though)

10-09-2017, 11:14 PM   #2
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I've owned a 645 since 1986 and have never had a problem as you've described. Can you upload and show the take up reel when you have it cued to the arrows, just before loading into the camera? Of course I assume you are loading 120 film into a 120 back and not 220.

Is this a new problem or is it a newly obtained camera? Did the camera wind correctly until just recently? Did it get progressively worse, or just started to be an instant problem?
10-09-2017, 11:28 PM   #3
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QuoteOriginally posted by Thenorthernmonkey Quote

I sacrificed an old film, loaded it into the camera and wound it through manually, I found there is quite a lot of resistance, and the further through the roll you get, the tighter the film and more resistance there is, until eventually it is difficult to wind the film manually towards the end of the roll.
Decades ago I had an old Agfa folder with the same symptoms because the spindle on the loaded side was too tight. As the film is used the diameter reduces and the roll has to turn more for each subsequent shot.....the effort required to advance the film increasing as a result.

Bob
10-10-2017, 02:43 PM   #4
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I have a P645N but as far as I know the insert and winding mechanism is the same. I, like Alex645, have never experienced a problem. Do you have a second insert you could use to check if the problem re- occurs. It might help rule out if there is anything about the insert that is causing the problem. If it has to be coaxed through it suggests that as the film winds on to the top spool something add a lot of resistance which the batteries cannot overcome. What makes you sure the batteries are fine? I'd try a new set of good quality batteries such as Duracell. Avoid unnamed Chinese cheap batteries. If these do not cure the problem, even initially, then it suggests that something in the insert is not mechanically sound. If it works for the first few films but the problem then manifests itself again then it points to the insert again.

With brand new batteries you can at least eliminate batteries as the problem

asahijock

10-10-2017, 03:54 PM   #5
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I just tried what the OP did manually with some Fujichrome Velvia 50 that expired in 1996. As described, when you first start, it's easy to turn because you're only advancing paper and the take-up spool only has paper around the core, thus, little torque.

Once the tape and film reach the backing plate, the thicker media being bent backwards creates much more resistance. And then as the film advances onto the take-up spool, it does get increasingly harder to turn and takes greater torque. So all this is normal.

So in order of simple cause and solutions to more costly and complicated suggestions:
a) Is the film loaded correctly as pictured?
b) Are your AA batteries fresh? Although rated at 1.5V, with high quality Duracell alkaline, I get over 1.6V from new batteries and over 1.8V from lithium cells. I haven't tried rechargeable AA, but typically they run closer to 1.35V with higher amps but lower voltage. I would not recommend rechargeable batteries for the 645.
c) If you have all 6 batteries, try using a multimeter or volt meter to see if they are producing at least 9V collectively (6 x 1.5V). There could be a problem with the battery holder.
d) Is this problem with only one type of film or it doesn't matter if it's B&W or Color or Kodak or some other emulsion? Some emulsions like Kodak and European brands tend to be thicker, whereas Fujifilm tends to be more supple and thinner.
e) I've heard of the gears breaking in the 645, but then yours would simply not advance the film or would skip. So the worse case scenario is that the advance motor is worn and needs replacing. That's extremely rare and I would really be surprised if that's the cause....but it is possible. Of course if the gears need a bit of lube, that couldn't hurt as it is an older camera. Sometimes, I find putting the false back onto the camera and shooting 15, 30, 45 times may loosen up the mechanism a bit.
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10-11-2017, 02:27 AM   #6
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QuoteOriginally posted by asahijock Quote
I have a P645N but as far as I know the insert and winding mechanism is the same. I, like Alex645, have never experienced a problem. Do you have a second insert you could use to check if the problem re- occurs. It might help rule out if there is anything about the insert that is causing the problem. If it has to be coaxed through it suggests that as the film winds on to the top spool something add a lot of resistance which the batteries cannot overcome. What makes you sure the batteries are fine? I'd try a new set of good quality batteries such as Duracell. Avoid unnamed Chinese cheap batteries. If these do not cure the problem, even initially, then it suggests that something in the insert is not mechanically sound. If it works for the first few films but the problem then manifests itself again then it points to the insert again.

With brand new batteries you can at least eliminate batteries as the problem

asahijock
Hey, thanks for the reply. Yes the simple option would be to try a different insert but I don't know anyone else who is using a 645, NZ is such a small place there is probably nobody else in my city with one.
I was so sure about the batteries because I put in brand new batteries straight out of the pack, I think in hindsight though that maybe you are right, they are not big brand batteries and therefore maybe my first stop should be to try that. I just would expect brand new out of the pack batteries (not the cheapest on the shelf) would power at least one roll. I have also run other batteries in the past and had the same issue (cant remember what brand though) Any thoughts on using Sanyo Eneloop rechargeable batteries.
10-11-2017, 02:42 AM   #7
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QuoteOriginally posted by Alex645 Quote
I just tried what the OP did manually with some Fujichrome Velvia 50 that expired in 1996. As described, when you first start, it's easy to turn because you're only advancing paper and the take-up spool only has paper around the core, thus, little torque.

Once the tape and film reach the backing plate, the thicker media being bent backwards creates much more resistance. And then as the film advances onto the take-up spool, it does get increasingly harder to turn and takes greater torque. So all this is normal.

So in order of simple cause and solutions to more costly and complicated suggestions:
a) Is the film loaded correctly as pictured?
b) Are your AA batteries fresh? Although rated at 1.5V, with high quality Duracell alkaline, I get over 1.6V from new batteries and over 1.8V from lithium cells. I haven't tried rechargeable AA, but typically they run closer to 1.35V with higher amps but lower voltage. I would not recommend rechargeable batteries for the 645.
c) If you have all 6 batteries, try using a multimeter or volt meter to see if they are producing at least 9V collectively (6 x 1.5V). There could be a problem with the battery holder.
d) Is this problem with only one type of film or it doesn't matter if it's B&W or Color or Kodak or some other emulsion? Some emulsions like Kodak and European brands tend to be thicker, whereas Fujifilm tends to be more supple and thinner.
e) I've heard of the gears breaking in the 645, but then yours would simply not advance the film or would skip. So the worse case scenario is that the advance motor is worn and needs replacing. That's extremely rare and I would really be surprised if that's the cause....but it is possible. Of course if the gears need a bit of lube, that couldn't hurt as it is an older camera. Sometimes, I find putting the false back onto the camera and shooting 15, 30, 45 times may loosen up the mechanism a bit.
Hey Alex, thanks for your time, just had to get down to the mancave to get some photos...
a) film appears loaded correctly
b) Batteries fresh out of the pack..... are they high quality - no... are they real cheapies - no.... thinking like was suggested above maybe a fresh set of high quality is the way to go.... Just would like to avoid $25 on a gamble but maybe thats the way.
c) Tried the multimeter as you suggested - 8.69 volts - not enough you think?
d) This is the 5th film I have put through this camera, different film every time.... AND the 5th set of new batteries (cant remember what batteries I have used, but I have in the past - pretty sure not always the cheapies but really can't remember).
e) Certain it is not gears as the camera is very mint condition, looks barely used, works perfectly apart from this issue, no funny/grindy noises.

I have had it about 5 years and love it, except I hardly ever use it because it costs me a set of batteries every time, it is easier to use my Mamiya C220... or RB76... or even the spotmatic as they don't require batteries. Was thinking about selling it if I dont find a fix.

Looks like I am just going to have to invest in some expensive batteries to test it, just was trying to avoid it in case it doesn't work as I have a feeling I may have done that in the past but cant remember. I always end up just putting it back on the shelf out of frustration after each use... batteries are expensive here at probably $25 for 6 good batteries.
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10-11-2017, 09:02 AM   #8
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The 8.69 volts concerns me and is enough of an issue to cause the motor to struggle with advancing the end of the roll. That's about 1.45V per AA or one of the cells is bad. Since you have the multimeter, how much voltage are you getting from them individually?

The cost of buying 120 film, travel time invested in shooting, developing the film, and then either darkroom or Lightroom, then printing makes the batteries the cheapest part of the equation. I once used Costco branded Kirkland batteries, but found that even though I saved money, they didn't last as long and would let me down. So now I only use either the high end Duracell Quantum or Energizer Lithium cells.

From what you've described, I think your motor just needs more juice. Just yesterday I had a student buy 6 button cell batteries from Walmart, and when I tested them for him, found half were duds (rated 1.5V; 3 were around 1.6V and 3 were around 1.3V).

10-16-2017, 12:03 PM   #9
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Not a 645 owner and just spit balling here, but on 6x7s there is a regulated mechanism that counts out the length of the necessary film to equal a frame. The gearing alone can't be timed to pay out the length based on the position of the spool to the film role, so the spool might synchronized with roller to help keep constant measure the amount of film passing. On the 6x7 the "counting roller" and the winding mechanism has a spring tension clutch to allow for slippage as a cam engages and to regulate each crank until enough film is moved into position. I would say that the film holder must not be resetting something to a full open state after it is removed from the camera? So it sounds like the brakes are already engaged from frame one on. Don't have a diagram of holder or camera, but if someone does, could you verify this synchronization? Could be just a stuck arm or reset lever?
10-23-2017, 05:45 PM   #10
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I traded with a friend for a 645N that she had just purchased off ebay. I had those same problems. I tried 3 different film inserts. A few times it would work and then the problem again. Luckily, we were able to return the camera to the seller. My main camera is a Z and it really hurt to lose rolls of film.
10-25-2017, 01:51 AM   #11
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Ok, thank you for your replys everyone, I hope I have cracked it and it is as simple as batteries. Who would have thought the quality of battery would have made such a vast difference, I would have thought 8 volts plenty just to turn a film 1 frame and power a meter. Seems like the old 645 just takes a lot of juice to keep it going.

I went out and bought lithium batteries as advised, they ended up costing $35 in the end which seems crazy for disposable batteries, and is why I would have never done it before. The battery pack is now kicking out 10volts and the whole camera is working like a brand new machine, I have test shot my test film through about have a dozen times in quick succession and it just fire the frames through now with no worries at all. I just loaded it up with a brand new roll of Ekta 100 for the real test and I am only a couple of shots in so we will see eh!

Worth mentioning I also did another proper amateur mistake after loading the ekta, (my excuse is that I was loading on the run, literally on the way down the street). I loaded the film switched on the camera and - nothing. dead.... the LCD showed M1000 and would not change to anything else, nothing functioned at all. Took out and reloaded the film, made sure the film back was seated properly, the lens was seated properly, still nothing..... missed a day of shooting. Left the camera a few more days out of frustration went through the same process again.

Eventually pressed the shutter button ( i have no idea why i didnt try that before). The camera wirred back to life, would the film onto the first frame, all functionality returned as normal - dohh! AFter a quick internet search it turns out that I am by no means the first to do this though.
10-25-2017, 02:00 AM - 1 Like   #12
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Couple of test shots on some 10+years old expired Ilford film, home scanned. Not that great but I think that is more down to my scan than to the camera.
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