Canon 7 slow speeds

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retinax

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Hello,
I've come across two different offers of Canon 7 cameras with sticky slow shutter speeds.
I take it that on many cameras, this can be addressed by cleaning and re-lubricating the relevant part of the shutter. How hard is this job on a Canon 7? Can it be done with the parts in place or is major disassembly necessary? I've done something like that on a Retina, if it's about the same level of difficulty, I'd go for it...
I assume that a camera without this issue might eventually develop it anyway, and I'd be curious to look inside the Camera in any case, so I'm tempted to jump for it, if you people tell me it can be done..
Thanks,
J.
 
If I remember correctly you can access the slow speed mechanism if you remove the body shell of the camera, no need to take the top plate off, so just a minor disassembly. The body shell is held on by the lens mount, the self timer and some screws on the front cover.

Google for a canon 7 service manual, I think it's available somewhere to download.

Nathan
 
Thank you, Nathan. I have this collection of exploded views which seems to be the closest to a service manual I can find (available here: http://pentax-manuals.com/manuals/service/canon 7 repair.pdf). Is there anything with more text?
Could you please help me identify the slow speed escapement on these drawings? Is it part CU 002 on page 10?
Nice of these folks at Canon that there are no hidden screws under the body covering!
 
Cleaning up the slow speeds is easy, you need only a couple of tools, a small slotted screwdriver, and a pair of pointed tweezers or pliers to remove the screw for the self timer.

You begin by removing the 4 screws which hold on the lens mount flange. Then lift off the flange slowly, there are shims underneath. Remove the shims carefully, they can be easily damaged, remembering how they came off, they must be put on the same way they came off. After the shims are out of the way, remove the two black screws which were hidden by the shims.

Next, remove the self timer by unscrewing the screw with the two holes using your tweezers or pliers. Lift off the lever (the timer will run on a little bit), then remove the three screws underneath. Lift off the small plate held on by the screws, being careful not to lose the pinion and the slotted coupler.

Then remove the four black screws on the front cover. Open the film door, then lift the body shell off the front of the camera.

With the shell off, you'll see the slow speed escapement on the bottom, below the shutter curtains. A few drops of lighter fluid will free it up. When testing the shutter speeds, the slow speeds should work properly after cleaning, but faster than 1/8 will not work properly with the body shell off.

Clean the rotten foam rubber from the corners of the camera body, and clean the inside of the body shell before you put it back on.

The only tricky part about putting the camera back together is getting the self timer on correctly. After you put the coupler and pinion, and the plate and three screws back in, put the self timer lever on backwards, and wind the self timer 180 degrees, pull the lever off and quickly put it on while the timer is running. The timer normally runs well past vertical, and the bottom screw stops the travel. If the timer stops, and the lever is not pointing straight up, repeat the above steps, winding the self timer a little further before putting the lever back on.
 
Thank you, wonderful explanations! I haven't bought one yet, scared of GAS for ltm lenses that will follow... but I probably will, soon! I'll keep you updated, probably with more questions!
 


The Canon VI-L that I have is similar - and this is that.

On the VI-L you don't need to remove the self timer. I'd imagine the 7 is the same - with those pin faced screws it's easy (for me anyway) to scratch them, so give it a try. I use a little adjustable wrench to reset the self timer thing before I put the body back on.
 
Frontman said:
Cleaning up the slow speeds is easy, you need only a couple of tools, a small slotted screwdriver, and a pair of pointed tweezers or pliers to remove the screw for the self timer.

You begin by removing the 4 screws which hold on the lens mount flange. Then lift off the flange slowly, there are shims underneath. Remove the shims carefully, they can be easily damaged, remembering how they came off, they must be put on the same way they came off. After the shims are out of the way, remove the two black screws which were hidden by the shims.

Next, remove the self timer by unscrewing the screw with the two holes using your tweezers or pliers. Lift off the lever (the timer will run on a little bit), then remove the three screws underneath. Lift off the small plate held on by the screws, being careful not to lose the pinion and the slotted coupler.

Then remove the four black screws on the front cover. Open the film door, then lift the body shell off the front of the camera.

With the shell off, you'll see the slow speed escapement on the bottom, below the shutter curtains. A few drops of lighter fluid will free it up. When testing the shutter speeds, the slow speeds should work properly after cleaning, but faster than 1/8 will not work properly with the body shell off.

Clean the rotten foam rubber from the corners of the camera body, and clean the inside of the body shell before you put it back on.

The only tricky part about putting the camera back together is getting the self timer on correctly. After you put the coupler and pinion, and the plate and three screws back in, put the self timer lever on backwards, and wind the self timer 180 degrees, pull the lever off and quickly put it on while the timer is running. The timer normally runs well past vertical, and the bottom screw stops the travel. If the timer stops, and the lever is not pointing straight up, repeat the above steps, winding the self timer a little further before putting the lever back on.
Click to expand...

Hi, after I done all these steps still have no luck to make the speed 1/8 - 1s to work. Any other idea? :bang:
 
tenchi0205 said:
Hi, after I done all these steps still have no luck to make the speed 1/8 - 1s to work. Any other idea? :bang:
Click to expand...
Not sure about the 7, memory vague. But there is an adjustment on the P at the shutter speed dial itself. On the 7 photo someone posted here, just to the left of the shutter curtain on the left side is a thin rod that goes from top to bottom. This rod rides on a cam around the shutter speed mechanism (under the top plate). Its position feeds down to the slow speed escapement below the shutter.

See if that rod move in and out at the top. We're talking small distances here- maybe 1-1/2mm in total from 1 to 1/8? (1/15 and 1/30 have a second adjustment mechanism, and then 1-60 to 1/1000 have a third one). There is an adjustment for the cam position that changes speeds here.

Again, I am certain that what I am saying applies to the P but not certain about the 7.
EDIT: OK< looks as if the 7 has 1-1/30 in a group, more typical. Here is the manual I have on this-

Adjustment of slow shutter (l - l/30)
Loosen Screw S1207 and make the adjustment by turning Eccentric Collar
C2497 to right or left.
By removing the Shutter Speed Dial this adjustment can be performed with
two small screwdrivers without taking off the Top Cover.
See Repair Manual page 8.
 
Don't just open up the shell and put a couple drops of solvent on the mechanisms, that's a quick and dirty fix but won't address the problems in the longer term (which are most likely dried up lube & dirt... By just putting some solvent on you're only drying it up even more). I would also advise: if the speed adjustments were never messed with before, don't tinker with them, fix the problems that need fixing, if everything is running smooth as intended, the speeds should fall in the right ballpark with the factory set settings.

For the slow speed escapement: you want to take it out (it's held by two screws from the bottom, look at the exploded views in the repair "manual"). Soak it in solvent like naphtha/white spirit and move it a couple times, have an ultra-sonic-cleaner? Good, use it. Let it dry out completely (a rocket blower is good for blowing out rest of the solvent). Take a light watch precision oil (something like Möbius 9010 or some equivalent), take a precision oiler or a needle/pin and put a _miniscule_ amount of it on the bearings:
slowspeeslubrication.jpg


This one if from a screwmount Leica, but the Canon ones are essentially the same. The triangles are where your miniscule amount of watch oil should go (same on bottom = 6 points for the canon escapement).

Stealing from mooges thread about M4 vs Canon7 differences:
37531574844_ec0eaf9f8a_c.jpg


See that part at the front in the middle with the black rod going down? That's the part that controls the slow speed escapement. When changing your shutter speeds (1/30 to 1 sec.) this should move to different positions. I haven't worked on a 7, only on a P, but both look to work pretty similar. Is it stuck? If so, it needs a cleaning at its bearing and relubing! On my P it was a dried up and sometimes hanging, which resulted that slow speeds sometimes worked and sometimes not.

See a pattern? ;) Cleaning old grime out, bringing new lubricants in :D

If you have the top off. Take out the whole speed cam module (it's held by 3 screws and comes off as a whole unit). Do the same as described with the slow speed escapement, soak it, dry it out, relube all parts that move as needed. For contact points of different rods and cams and stuff that isn't powered by springs and needs low friction you can take some light PTFE-grease.
Take a look at the moving parts below the speed cam module, are they all moving freely? If not: clean&lube ;)

There's another factor which controls the running of the slow speeds: it's the force of the second curtain tension. Of course you want its roller, all gears etc. connected to it to run freely and smoothly. You can take your (not too aggressive) solvent of choice, a syringe or something which lets you apply the solvent in a controlled way, some smallish artists brush to get under the gears and stuff and clean the old lube and dirt out of every gear on the bottom of the camera. Flush it several times... DON'T let solvent get on the curtains and ribbons! Dry everything with a rocket blower each time between flushes and cleanings. If it's all clean: lube the bearings of every gear and of the rollers with a TINY drop of your light precision watch oil and a precision oiler/needle.

Congratulations, here you have pretty much performed a basic CL(without the A) on the shutter ;)

After all that: hope that the curtain tension was never messed up in order to overcome the added friction from dried up lubricants and dirt... otherwise you need to reset it from scratch or your times will be off. It's not that difficult to do, but you'll need some tools for it like a proper shutter speed tester... OR a digital camera + some sort of rig, using the digital camera as a sort of shutter speed tester, but that's a story for another time ;)

Work slow and deliberate, before taking anything apart see and learn how each part goes into another and work together! Don't disassemble parts that you absolutely don't have to (like gears at the bottom, which need to be much likely put in _exactly_ the same position they were in). There's not much documentation on Canon rangefinders, but quite a bit on Leicas... much of the stuff works either the same or very similar.

And less lubrication is more! Don't soak everything up!
 
On a Canon 7 the clam shell body has a lever that interacts with the slow speed unit in the camera base for if my recollection is right 1/8 and 1/16 and then the lever in the clam shell is released, releasing pressure on the lever on the slow speed unit. If the lever fails to apply the appropriate pressure on the slow speed unit lever this will result in either a high speed result at 1/8 and 1/16 or a 1 second or so exposure time for those settings. On the slow speed levers in the camera top is an adjustment for 1/250 second! The slow speed lever in the camera top has two parts, one lever part rests on a rotating unit for setting the speeds and one lever part touches a rotating wheel that moves the second curtain that is not round but designed with slight bumps and one large indentation from the ~ round form. The slow speed levers have a height limiter, a pressure lever that can be bent to restrict the height that the lever will move. Also, there is an oval unit on a screw for adjusting the lever in the camera top to the left of the speed setting unit and additionally an out of round screw to the right of the speed selector unit primarily used to set the B setting so upon release the second curtain will close. The design effort for the Canon 7 and 7s is impressive...at least for me..maybe I am easily impressed...but when everything is synchronized properly these are fine cameras! Hint, when confronted with a meter that will not operate on the 7s check under the hood so to speak...by using and abrasive to clean the contacts on the battery switch on both sides. Also, move the shield on the sensor unit, to the side and clean the sensor face very carefully as it appears that tinted "contact lenses" are used in calibration which may oxidize. Take your time to get the lens repositioned so it does not lean from position if it is removed and be very gentle. Best of luck....
 
Filzkoeter said:
Don't just open up the shell and put a couple drops of solvent on the mechanisms, that's a quick and dirty fix but won't address the problems in the longer term (which are most likely dried up lube & dirt... By just putting some solvent on you're only drying it up even more). I would also advise: if the speed adjustments were never messed with before, don't tinker with them, fix the problems that need fixing, if everything is running smooth as intended, the speeds should fall in the right ballpark with the factory set settings.

For the slow speed escapement: you want to take it out (it's held by two screws from the bottom, look at the exploded views in the repair "manual"). Soak it in solvent like naphtha/white spirit and move it a couple times, have an ultra-sonic-cleaner? Good, use it. Let it dry out completely (a rocket blower is good for blowing out rest of the solvent). Take a light watch precision oil (something like Möbius 9010 or some equivalent), take a precision oiler or a needle/pin and put a _miniscule_ amount of it on the bearings:
slowspeeslubrication.jpg


This one if from a screwmount Leica, but the Canon ones are essentially the same. The triangles are where your miniscule amount of watch oil should go (same on bottom = 6 points for the canon escapement).

Stealing from mooges thread about M4 vs Canon7 differences:
37531574844_ec0eaf9f8a_c.jpg


See that part at the front in the middle with the black rod going down? That's the part that controls the slow speed escapement. When changing your shutter speeds (1/30 to 1 sec.) this should move to different positions. I haven't worked on a 7, only on a P, but both look to work pretty similar. Is it stuck? If so, it needs a cleaning at its bearing and relubing! On my P it was a dried up and sometimes hanging, which resulted that slow speeds sometimes worked and sometimes not.

See a pattern? ;) Cleaning old grime out, bringing new lubricants in :D

If you have the top off. Take out the whole speed cam module (it's held by 3 screws and comes off as a whole unit). Do the same as described with the slow speed escapement, soak it, dry it out, relube all parts that move as needed. For contact points of different rods and cams and stuff that isn't powered by springs and needs low friction you can take some light PTFE-grease.
Take a look at the moving parts below the speed cam module, are they all moving freely? If not: clean&lube ;)

There's another factor which controls the running of the slow speeds: it's the force of the second curtain tension. Of course you want its roller, all gears etc. connected to it to run freely and smoothly. You can take your (not too aggressive) solvent of choice, a syringe or something which lets you apply the solvent in a controlled way, some smallish artists brush to get under the gears and stuff and clean the old lube and dirt out of every gear on the bottom of the camera. Flush it several times... DON'T let solvent get on the curtains and ribbons! Dry everything with a rocket blower each time between flushes and cleanings. If it's all clean: lube the bearings of every gear and of the rollers with a TINY drop of your light precision watch oil and a precision oiler/needle.

Congratulations, here you have pretty much performed a basic CL(without the A) on the shutter ;)

After all that: hope that the curtain tension was never messed up in order to overcome the added friction from dried up lubricants and dirt... otherwise you need to reset it from scratch or your times will be off. It's not that difficult to do, but you'll need some tools for it like a proper shutter speed tester... OR a digital camera + some sort of rig, using the digital camera as a sort of shutter speed tester, but that's a story for another time ;)

Work slow and deliberate, before taking anything apart see and learn how each part goes into another and work together! Don't disassemble parts that you absolutely don't have to (like gears at the bottom, which need to be much likely put in _exactly_ the same position they were in). There's not much documentation on Canon rangefinders, but quite a bit on Leicas... much of the stuff works either the same or very similar.

And less lubrication is more! Don't soak everything up!
Click to expand...

Done all...still same :bang:

Shafovaloff1 said:
On a Canon 7 the clam shell body has a lever that interacts with the slow speed unit in the camera base for if my recollection is right 1/8 and 1/16 and then the lever in the clam shell is released, releasing pressure on the lever on the slow speed unit. If the lever fails to apply the appropriate pressure on the slow speed unit lever this will result in either a high speed result at 1/8 and 1/16 or a 1 second or so exposure time for those settings. On the slow speed levers in the camera top is an adjustment for 1/250 second! The slow speed lever in the camera top has two parts, one lever part rests on a rotating unit for setting the speeds and one lever part touches a rotating wheel that moves the second curtain that is not round but designed with slight bumps and one large indentation from the ~ round form. The slow speed levers have a height limiter, a pressure lever that can be bent to restrict the height that the lever will move. Also, there is an oval unit on a screw for adjusting the lever in the camera top to the left of the speed setting unit and additionally an out of round screw to the right of the speed selector unit primarily used to set the B setting so upon release the second curtain will close. The design effort for the Canon 7 and 7s is impressive...at least for me..maybe I am easily impressed...but when everything is synchronized properly these are fine cameras! Hint, when confronted with a meter that will not operate on the 7s check under the hood so to speak...by using and abrasive to clean the contacts on the battery switch on both sides. Also, move the shield on the sensor unit, to the side and clean the sensor face very carefully as it appears that tinted "contact lenses" are used in calibration which may oxidize. Take your time to get the lens repositioned so it does not lean from position if it is removed and be very gentle. Best of luck....
Click to expand...

no clue at all...

paperino said:
You can follow this:

https://www.youtube.com/watch?v=PwfYwHEjoAo&t=146s
Click to expand...

Watched several times...still no luck
 
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