Sunday, March 7, 2021




The film’s feed reel sits on the post at the top of the camera and allows the film to be pulled through the gate. The claw, using a combination of pressure plate tension, the pulling action of the take-up reel, and the film drag roller (located at the bottom of gate area) all combine forces to pull the film intermittently through the gate. 

When the claw is not actively pulling film with the motor running, the film is held in place and does not wind onto the take-up reel. An overrunning clutch on the take-up reel keeps tension on the take-up reel at all times the motor is running. If the film slips out of synchronization, the camera will stop and/or not start. This usually means one or more of the following has occurred:

   11)   The film has slipped out of the center slot of the take-up reel and is not being pulled through the gate and wound onto the take-up reel. The camera’s claw will misregister and stop.  This is the most common cause of film stoppage.

You cannot directly see if the film has slipped out of the take-up reels’ slot. It is typically held in place with 2 or 3 turns of film stock. If the end of the take-up reels film falls out of the reel’s slot, the reel will then not be able to pull film thru the gate properly and this will cause a mis-registration and the camera will stop.

Any time the claw is out-of-sync with the  film’s registration sprocket holes, the claw will mis-misregister and the camera will stop. Usually, pulling out and then pushing the  pressure pad or claw lever, will correct any registration problems. This will not fix a film leader that has slipped out of the take-up reel’s slot.

 2  2)   The film slack tensioner is located at the top of the gate area and pivots at the tip of the claw cover. Its purpose is to take up the slack and smooth out the “tugs” that the claw imposes on the film stock. Sometimes the tensioner's small coil spring breaks or  the spring’s tip can “pop under” it’s retainer bar and the spring then becomes ineffective.

When the film is then pulled through the gate by the take-up reel, the tensioner, if not properly doing its job, may cause the film’s drag to exceed the maximum allowable and the film may become misregistered resulting in the camera stopping. This can be an intermittent or continuous problem.

3)  3) Another problem is the pressure plate backing spring can become weak over time, thus allowing the film to be pulled through faster and cause misregistration.

4)   The previous owner of the camera may have added and short length of electricians tape to the front of the pressure plate to add additional “drag” between the film and the tensioner.  The tape may be the cause of the problem. 

5) The gate area can be dirty and cause excessive drag.

6) A worn or damaged lower drag roller and the bottom of the claw cover can     allow the film to intermittently move out of registration and the camera will stop.

7) The tip of P1-2-3 reflex camera’s lower drag roller’s backwind pawl spring, located at the lower section of the claw cover, can break. Tip breakage or slippage can allow the take-up reel to move the film faster than normal and cause the camera to misregister.

8) The take-up reel clutch can partially or intermittently seize which can cause the camera to misregister.

If these common problems aren’t the cause, it may because one or more of them are intermittent and interacting with each other. If inspection showed no obvious problem(s), I recommend running a test roll (old or used film stock) through to find and fix or eliminate the problem.


Using the ½ roll of film and with the door open, thread the ½ roll of film onto the take-up reel and run about 10 seconds of film and then, with your finger tip and the camera still running, press down on the bottom part of the take-up reel, slightly, to stop it from turning. With the reel stopped, let the camera run for another 5 seconds or so. Then take your finger off the take-up reel and watch the take-up reel “pick up” the slack. You can see the loose film wind itself around the take-up spool taking up the excess slack.

After 5 more seconds of the film being rewound onto the take-up reel. Stop the motor and try turning the take-up reel clockwise with your finger. It should stop within one turn. If it continues to turn indefinitely, the film’s leader has slipped out of the reel slot.





Wednesday, October 30, 2019


The OUTER SHUTTER ASSEMBLY gears are the two, small sliding gears that control the angle of the dual-blade variable shutter assembly from approximately 165 degrees to 360 degrees (closed) and are buried within the front shutter housing.  

The gears controlling them are oiled. If the gears were greased, use a suitable chemical solvent (denatured alcohol) to dissolve and remove the grease. If the gears are NOT greased, re-oil them per Bolex specifications.

The INNER SHUTTER assembly consists of two, 180 degree blades that overlap to control the adjustable shutter angle. Normal shooting angle is 165 degrees. 

This is shown as a silver half-moon on the shutter dial. The location of the inner shutter blades is accessible when the shutter housing is disassembled for overhaul. The shutter blades themselves are never lubricated

The SPEED REGULATOR is NOT lubricated, except for the ends of the regulator. Located at the rear of the case is an “oilite” bearing (sintered bronze) that supports one end of the regulator. It is greased. 

The other end (front) of the regulator IS oiled and NOT greased. The front part of the regulator interfaces with an intermediate gear that is driven by the spring motor.

Sometimes a non-Bolex camera repairman will improperly lube both ends with grease or oil both ends. Doing this can allow excess oil/grease to be thrown onto the speed regulator’s “puck.”

The puck is small, circular piece of leather than provides a “fixed” friction value against the regulator's friction wheel. If the puck has oil or grease on it, the regulator will not control the camera’s film speed accurately. 

If the regulator has been improperly lubed, a chemical, such as denatured alcohol,  can be used to dissolve the grease before lubing.

Thursday, February 21, 2019


1)   Film misregistered.  Claw stops in the middle of sprocket holes which, in turn, stops the camera.  Reload film or move the film slightly and close the lever.

2) Shutter dial rotated full clockwise (locking lever control pointing up). Now locked, this stops the camera from running.

3) The camera is overwound. Bolex states in the manual that it is “impossible” to overwind a Bolex camera. Wrong. You can overwind a Bolex camera motor. There are two gears with a different number of teeth on each. One gear has what appears to be a double-tooth. This functions as a stop to prevent winding. Excessive winding torque can case one gear tooth to "jump" over another tooth. This, typically, limits the run to a few seconds before lockup. Rewinding the motor with about a turn or so results in the same lockup.

4) The shutter has an internal problem.

5) A loose piece of dirt and/or sand has found its way into the inside of the camera and is wedged as a "lock" for meshed motor gear(s).

6) Camera speed dial set to less than 12 FPS. Motor may or may not run. Dial does not have to be fully rotated counter-clockwise to stop the motor. The drag on internal gears and lubrication will affect motor stopping at below 12 FPS. Some Bolex cameras (model dependent) are marked and can shoot at 8 FPS.

7) "Release selector" set to "lock." The "Release Selector" is located just forward of the shutter control lever. The is a small chrome lever has a small protrusion just slightly outside the shutter housing case. There are four positions:

When the lever is rotated up, the camera is locked, and the motor will not run.

When the lever is centered, the camera is in "single frame" mode.

When the lever is down, the camera is in the normal, run position and will film as long as the run button is held down.

While the camera motor is running, the lever can be pushed down a small, additional amount. This will engage the continuous or “run lock” position often used for self-filming. If the run-lock / continuous position is selected, winding the motor will cause the motor to free run.

Thursday, March 8, 2018


Normal Bolex 8mm motors wind from complete rundown to full wind about 11 1/2 full or 22 half turns of the winding key.  If your motor won't wind, or runs only for a few seconds, the motor may be overwound.

Customer writes to say that, "the motor runs for a second or so, and then stops. It won’t wind more that a fraction of a turn and then stops”.

From the description, it sounds like the motor is overwound. Bolex states in writing that their motors "cannot be overwound", but in actuality, they can be overwound. 

It takes a lot of force and if the camera has been used a lot, or there is excessive wear in the limiter gears, overwinding can happen.

Overwinding causes the winding limiter ( two slightly different gears that intermesh ) to “slip one over the other” from their factory setting. This causes a loss of the gear’s relative indexing and now the motor winds only a little. 

Sometimes after an overwind the spring is still okay and just needs the limiter gears to be reset.

In other cases, the motor’s spring can be damaged (bent) when the initial overwinding slippage takes place. Rapid unwinding can permanently damage the flat spring.  This can result in a permanent kink in the flat spring of the motor and the only fix is to replace the motor.