How do I adjust my (older style) M-Winder?
Find your older-generation M-Winder jerks your camera far too much every time you press the shutter? Find it too noisy? Ever wonder how to open it up and adjust the motor tension spring so that it will run as smoothly as possible?
As luck would have it, John Campbell set up a www-page with detailed photographs explaining how to do all of these things:
Unfortunately this page vanished some time during 2003. With a bit of luck you may still be able to find it in a search engine cache - hence my reason for still listing it.
Furthermore, a few months after Campbell's page vanished, Mr Collier was kind enough to supply the following copy of the description of how to adjust the motor:
Adjusting the Leica Winder
First of all we need to understand how the winder operates. When you trip the shutter on the camera the tension is removed and the spring (4) rotates the motor assembly counter-clockwise. The shaft (1) attached to the motor then releases the microswitch (2) to energize the motor which advances the film and cocks the shutter. With the shutter cocked and the film advanced the camera in a sense "locks-up". The motor keeps running, torqueing itself up against the spring tension causing the whole motor to rotate clockwise until the shaft (1) trips the bottom half of the microswitch (2) disconnecting the power to the motor. The whole unit (camera and winder) stays under tension until the shutter is tripped and the process starts over. This is one of the reasons why Leica switched from brass gears in the M3 to steel gears with the M4-2.
So why are so many Leica winders loud and feel like they are tearing up your camera? There are two common problems. First the the spring lever (4) hitting the inside of the winder case and second, the shaft (1) hitting the padded stop (3).
I'll assume you have already removed the motor assembly from the winder housing. Remember there are two wires connecting the motor to the battery contacts in the winder housing. As you are working on the assembly be careful not to pull the wires loose.
We need to address the spring lever first. Loosen the nut holding the padded stop (3) and adjust the stop until the spring lever (4) is flush with the motor mount. Most winders I have adjusted have had the stop set so the lever hits the inside of the case causing a loud "thwak". You can actually feel the winder body expanding from the lever hitting it.
Now we need to adjust the microswitch (2) so the motor rotates as little as possible during the cycle. The second loudest noise in the process is the motor shaft (1) hitting the padded stop when the tension is released by tripping the shutter. If you did step 1 the the microswitch is now totally out of adjustment. Loosen the screw (2) holding the microswitch and move the whole switch assembly so that if the motor shaft is against the stop (3) the motor is running and as you rotate the motor away from the stop, the motor turns off. You want to set the microswitch so you get the least amount of movement of the motor between the "on" and "off" states. The less the motor rotates the less impact the motor shaft (1) has on the stop. The easiest way to check this is to put the battery pack on and rotate the motor by hand to see how much it has to move before it turns off, remember you'll need to turn the winder "ON" by holding the other microswitch closed. The "ON - OFF" microswitch is the only other switch in the unit, it is attached by two wires and is tripped by the release lever that attaches the winder to the camera body. Since the winder is apart the switch is in the "OFF" state.
Now is a good time to also check the pad on the stop (3). M4-2 and M4-P winders have been around since the 70s and the pads tend to get hard. New pads may be available from Leica or use any type material that has the same density. Just rotating the pad 90 degrees can help.
Of course for the above to make better sense, you will have to refer to the couple of JPEG images which accompanied Campbell's original article. See the following:
FWIW, this topic (and the above instructions) also appeared online in Feb 2004 at: <Photo.net: #007Pco>