16 MM Bolex H -16 Spring Motor Stuck

[David Rovine]

I acidentally wound the spring motor to tight, on my Bolex H-16 camera, and now its stuck. does anyone know what I can do to fix the spring motor from being unjammed.

 

 

 

Thanks

Dave

[Zachary Vex]

My Bolexes have a stop that prevents them from being over-wound. Check that the switch above and to the left of the crank is set to the Motor (upper) position... it may have been moved.

[Bernie O'Doherty]

Hi Dave,

 

Definitely do check the M/O lever at the top and make sure it's at M. If that wasn't the problem, there are a couple of things you could try.

 

Bring your frame rate down to 12fps. Press the run button back all the way left into the M position and let it click into constant-run mode. Open the door and take out the pressure plate. Get a pair of leather gloves and try turning the film rollers (with the teeth) clockwise or counterclockwise very slightly in case there is some dirt or debris (film chips) impeding the movement). If it runs, you're over the hump.

 

If not, put the pressure plate back in, close the door, keep the M/O lever at M and the on/off switch at M. Get a small rewind crank and try cranking ever so slowly clockwise or counterclockwise. If there is too much resistance, don't go any further. If, however, you find that with a little pressure it becomes much easier to turn, you've probably solved the overwinding problem. Try your on/off button and fingers, legs, and eyes crossed, it will work. Otherwise, bring it to a good technician.

 

Cheers,

Bernie

[Edward Jurich]

Just in case someone has the same problem. I let my H-16 sit for 10 years and when I went to check it, it was frozen. All the suggestions mentioned above did not work. I had mine apart in the 1980's to lubricate so I took it apart again. Sprayed 'Liquid Wrench Silicone' all inside and into the claw movement. Even after that it would not budge. What worked was to slowly turn the shutter blade clockwise and after about four turns it started running on its own.

This requires careful work. You have to remove several parts off from the rear so the camera can be pulled out of the case. Then the turret has to be removed. After removing the screws holding the turret the turret and gate plate slide forward off the camera being careful not to bend the shutter blade. Remove five screws holding the camera in the case and the camera slides out of the body.

Be aware that with the turret and gate off the claw will try to spring forward and hit the shutter. A small screwdriver can be used to hold the claw from flying out while turning the shutter blade clockwise. It would be best to use the single frame trigger so the shutter blade will only spin around once at 8 or 12 FPS once it frees up.

[Dom Jaeger]

Just in case someone has the same problem... Sprayed 'Liquid Wrench Silicone' all inside and into the claw movement. Even after that it would not budge. What worked was to slowly turn the shutter blade clockwise and after about four turns it started running on its own.

 

 

Yikes! Silicone spray should never be used on film movie cameras! You won't find a service manual anywhere that recommends it, even though it seems like a reasonable thing to do. The explanation is that movie cameras often use adjustable amounts of friction in the mechanical workings, which silicone completely destroys. For example the claw in a Bolex is pushed against the film and hooks into a perf due to the friction in the pivot; the film remains stationary in the gate even as the claw retracts back across the perfs because of the pressure plate friction; the take-up spindle slips as more film is wound onto the take-up spool but it needs to still have some resistance in order to wind the film on tightly enough to avoid cinch scratches etc..

Also silicone will migrate and can easily get onto optical surfaces such as the important viewfinder prism in a Bolex where it will adversely affect the image quality. Once applied, silicone is nearly impossible to remove.

The jam was probably due to something contaminating the shutter gears. Bernie mentioned earlier not to force a camera to turn over - this is because it can be dangerous if the contamination is hard, like a piece of metal, as it will damage the gear teeth. Or maybe something is catching and it will be bent or do damage if forced. But sometimes it might just be a dried lump of grease or something that will just compress without too much force being applied and then everything works again.

[Edward Jurich]

The camera is running fine. The governor would be the main concern, it's really the only thing that uses friction as a control, at least in my H-16. The speed control is fine. Also, most of the spray has evaporated, the amount of silicone left is very slight. After the drive loosened up I used a can of air to blow out the excess spray. I did use silicone grease on the gears and a couple spots where metal rubs on metal. I would have used Teflon grease but could not find any, perhaps next time. I've got a roll of TRI-X I'll use to test the Bolex when finished.

http://ejjamps.weebly.com/bolex.html

[Edward Jurich]

For example the claw in a Bolex is pushed against the film and hooks into a perf due to the friction in the pivot; the film remains stationary in the gate even as the claw retracts back across the perfs because of the pressure plate friction;

 

Forgot to mention, my H-16 has the dual claw, a second claw holds the film in place while the pull claw goes down.

[Jean-Louis Seguin]

Incorrect. One claw advances the film in the forward direction. When reversing, the other claw takes over the job.

 

Jean-Louis

[Chris Millar]

The governor would be the main concern, it's really the only thing that uses friction as a control, at least in my H-16.

 

Well, strictly, the control in a governor is an outcome of a simple and clever application of the laws of angular momentum. Dom/Jean-Louis will be able to advise as to the correct cleaning and lubrication of that part. If I recall I remember seeing something that looked like graphite in one of mine, but who knows if it was applied at or after the factory ...

[Edward Jurich]

Incorrect. One claw advances the film in the forward direction. When reversing, the other claw takes over the job.

 

Jean-Louis

 

You know, I've never wound mine backwards so you are probably correct. I never tried doing any effects in the camera, strictly shot straight scenes. I bought this camera used in 1971 from Altman Camera in Chicago. The camera sat apart all night and this morning the spray I used to loosen things up has pretty much evaporated. There is only a slight coating of silicone remaining, so slight you can hardly tell. The silicone grease is still on the gears of course. Looking down into the bell of the governor I don't see anything that looks like graphite or any kind of lube, touched a q-tip in the bell and it came out clean. I'll reassemble it later today and run an old 100' roll through to make sure it's pulling film OK before shooting a test roll.