This is my first post here, so I hope I do everything right 
I recently purchased a Konica (I model, as in the first one, Type Cs from 1949) and it worked great, however the shutter stuck at most lower speeds. I could not find a single good resource on this particular shutter system, so I decided I'd try my hand at it and I figured I'd leave it here for future reference.
NOTE:
I am by no means a camera repair expert, and I of course take no liability for any damages caused by the below methods, I am just sharing what worked for me and improved the function of my camera. Caution must be used throughout this process to avoid damage or disfigurement of your precious camera!
I don't want to scare anyone away from this, but this may be better left to those with more mechanically adept hands.
In this process I use a small (2mm) watchmaking screwdriver, some tweezers, an ultrasonic cleaner, a heat gun, and some watchmaking oil with an oil applicator.
I apologize in advance for the image quality; I was overcautious in trying to make the images small enough to upload.
To access the shutter section, the front lens must first be removed. If it won't immediately unscrew by hand, you can use something like a rubber block eraser against your palm to spread force across the knurling; this worked for me and unscrewed the lens. If only the front element unscrews and you are left with the rear element...
... a spanner wrench can be used to remove it.
This small locking cam will have to be CAREFULLY rotated using a fine tipped tool. I'm sure an adequately small spanner bit/tool will turn it, but I had to use the end of some tweezers, which worked fine. WHEN USING TWEEZERS, you may slip and scratch the front plate! This happened to me on one occasion, but lightly and on an area covered by the lens assembly.
This matte finish plate with the "KONIRAPID-S" text can be rotated a small amount, and the small cutout where the cam locked can be used to lever the plate off.
At this point, the shutter speed control dial can be gently pulled off, as it is press fit.
The shutter cocking lever is similarly fit around the center of the mechanism, and can be removed by gently pulling it up on both sides while rotating it back and forth. It has a spring attached to a plate under the screw on the left, and this should be gently disengaged from its post before unscrewing the two larger screws pointed to in the image with the tweezers.
At this point, the shutter delay mechanism and the spring retention plate can be removed. I put the delay mechanism into an ultrasonic cleaner (inside of a small beaker set within the ultrasonic bath, as one may clean watch parts) and after running a cycle with a cleaner and then with water, I rinsed it off and used a heat gun to dry it.
I then applied a small amount of watchmaking oil (type 8000/4 from Moebius) using a watchmaking oil applicator (from a Bergeon 4-piece set) onto the exposed gear pivots.
After this, I put the mechanism back into place with the spring plate and screwed it down - but there is a catch!
Make sure to distance it from the outer edge of the mechanism, as otherwise one of the larger gears will press against the outer wall and will not spin. I simply gently pressed a fingernail/tweezers between the mechanism and the wall while screwing it back down. The shutter cocking lever can be put back, but take caution to "thread" the spring under a small lever that is operated by the shutter release. Make sure the mechanism operates freely before further reassembly; the lever on the right side will need to be rotated to spin the other gears freely. l
The end of the cocking lever spring should have a few loops bent at an angle, which you can put over the post using tweezers before seating the lever ring. You may have to push the small lever by the shutter release out of the way to fully seat the cocking lever. After this, the selector dial can be press fit back on; I found it easiest to do with the shutter cocked and with the dial at the angle in this picture:
Take note to make sure the post on the bottom of this image fits in the slot, and the post on the right may need to be pulled out of the way of the dial during reassembly. After this, the plate with the cam and the lens components can be reinstalled in reverse order of their removal.
I would recommend using a blower to remove dust from any internal parts before sealing it back up, and of course I can not overstate the caution to be used in this process.
I would assume this process will be similar to that of other early Konica cameras among other makes and models, but this specific process is intended only for the Konica I / Standard / original model with the Konirapid-S shutter system.
I hope this can help someone out there and keep a Konica out in the wild!!!
I recently purchased a Konica (I model, as in the first one, Type Cs from 1949) and it worked great, however the shutter stuck at most lower speeds. I could not find a single good resource on this particular shutter system, so I decided I'd try my hand at it and I figured I'd leave it here for future reference.
NOTE:
I am by no means a camera repair expert, and I of course take no liability for any damages caused by the below methods, I am just sharing what worked for me and improved the function of my camera. Caution must be used throughout this process to avoid damage or disfigurement of your precious camera!
I don't want to scare anyone away from this, but this may be better left to those with more mechanically adept hands.
In this process I use a small (2mm) watchmaking screwdriver, some tweezers, an ultrasonic cleaner, a heat gun, and some watchmaking oil with an oil applicator.
I apologize in advance for the image quality; I was overcautious in trying to make the images small enough to upload.
To access the shutter section, the front lens must first be removed. If it won't immediately unscrew by hand, you can use something like a rubber block eraser against your palm to spread force across the knurling; this worked for me and unscrewed the lens. If only the front element unscrews and you are left with the rear element...
... a spanner wrench can be used to remove it.
This small locking cam will have to be CAREFULLY rotated using a fine tipped tool. I'm sure an adequately small spanner bit/tool will turn it, but I had to use the end of some tweezers, which worked fine. WHEN USING TWEEZERS, you may slip and scratch the front plate! This happened to me on one occasion, but lightly and on an area covered by the lens assembly.
This matte finish plate with the "KONIRAPID-S" text can be rotated a small amount, and the small cutout where the cam locked can be used to lever the plate off.
At this point, the shutter speed control dial can be gently pulled off, as it is press fit.
The shutter cocking lever is similarly fit around the center of the mechanism, and can be removed by gently pulling it up on both sides while rotating it back and forth. It has a spring attached to a plate under the screw on the left, and this should be gently disengaged from its post before unscrewing the two larger screws pointed to in the image with the tweezers.
At this point, the shutter delay mechanism and the spring retention plate can be removed. I put the delay mechanism into an ultrasonic cleaner (inside of a small beaker set within the ultrasonic bath, as one may clean watch parts) and after running a cycle with a cleaner and then with water, I rinsed it off and used a heat gun to dry it.
I then applied a small amount of watchmaking oil (type 8000/4 from Moebius) using a watchmaking oil applicator (from a Bergeon 4-piece set) onto the exposed gear pivots.
After this, I put the mechanism back into place with the spring plate and screwed it down - but there is a catch!
Make sure to distance it from the outer edge of the mechanism, as otherwise one of the larger gears will press against the outer wall and will not spin. I simply gently pressed a fingernail/tweezers between the mechanism and the wall while screwing it back down. The shutter cocking lever can be put back, but take caution to "thread" the spring under a small lever that is operated by the shutter release. Make sure the mechanism operates freely before further reassembly; the lever on the right side will need to be rotated to spin the other gears freely. l
The end of the cocking lever spring should have a few loops bent at an angle, which you can put over the post using tweezers before seating the lever ring. You may have to push the small lever by the shutter release out of the way to fully seat the cocking lever. After this, the selector dial can be press fit back on; I found it easiest to do with the shutter cocked and with the dial at the angle in this picture:
Take note to make sure the post on the bottom of this image fits in the slot, and the post on the right may need to be pulled out of the way of the dial during reassembly. After this, the plate with the cam and the lens components can be reinstalled in reverse order of their removal.
I would recommend using a blower to remove dust from any internal parts before sealing it back up, and of course I can not overstate the caution to be used in this process.
I would assume this process will be similar to that of other early Konica cameras among other makes and models, but this specific process is intended only for the Konica I / Standard / original model with the Konirapid-S shutter system.
I hope this can help someone out there and keep a Konica out in the wild!!!
