Resetting The Timing

Steel Rod Mechanism

Warning!  This is not a recommended end-user repair and should be done by an experienced technician. If, however, you’ve taken your camera apart and the diagram to the right doesn’t scare you, keep reading.

Three parts are involved in setting the timing:

• Shutter
• Claw
• Mirror

1. Set the shutter to be consistent with the claw:

Advance the claw (by rotating the lower gear on the transmission with your finger) until the claw just gets to it’s lowest position before retracting after pulling down the film — stop at the instant the pulldown stops.

At this point the shutter must be set to just be starting to open to expose the frame. Tighten the shutter.  Advance the mechanism and make sure that while the claw is in downward motion, the shutter is always covering the opening of the aperture plate. If the claw is pulling down the film, and the shutter is allowing any portion of the film to be exposed, then you will get vertical streaking of the image.

You will likely keep refining this adjustment until the shutter has just finished closing as the claw’s pulldown starts, and then the shutter just starts to open as the pulldown completes the instant before the claw starts to retract.

2. Adjust the mirror to cross the opening of the aperture only while the shutter is closed:

If you are lucky, maybe it is still set correctly. If not,loosen the 2 screws on the circular cam that the plastic rod connects to (DON’T LOOSEN THE 3 screws that actually hold the whole large round mechanism into the camera body! In other words, if you are starting to unscrew the plastic “oil splash guard,” you are too close to the outer edge of the mechanism.

Closer to the center is the cam that the rod connects to, with 2 screws). With those 2 screws loose, move the cam a little more to the right, or to the left, just by nudging the rod slightly — but hold the mirror shaft firmly where it is (you’ll accomplish nothing if you move the cam, but the mirror moves too!). Monkey around changing the position of this gizmo, retighten the screws, and see if the mirror is timing correctly, By loosening the screws, and nudging the cam, then retightening, you’ll eventually get it right (or as close as possible).

If the mirror hasn’t been re-centered it will never be 100% symmetrical; but there is a point of “as close as it gets.”.  (In some scenarios, if you don’t have enough extra room on the right or left to re-adjust the cam as much as you need, then take the screws out and re-screw into the opposite threads. Then start again.).

3. Test The Camera

Finally, test the camera under a strobe light (or at least shoot tests) to make sure the timing is perfect when the camera is rolling.