Questions about the spring motor
Posted 09 December 2011 - 09:51 PM
Also, do cold temperatures (5 degrees Celsius and less) affect the spring? I was filming and as the motor was at the end of its wind it sounded as it it was running slower. Is this normal? Is the speed still constant despite what I was hearing?
Posted 10 December 2011 - 08:26 AM
Bolexes are remarkably tolerant to temperature extremes - they've documented Everest climbs - but they need to be serviced to operate at their best. Most of the ones I've worked on slow down a little towards the end of the spring run, but if they're in decent condition it's no more than by 1 fps or so, and only in the last few seconds.
If you remember to rewind before each take it rarely becomes an issue.
Posted 29 December 2011 - 07:52 PM
My spring motor only gives me 24 seconds (24 clicks of the audible signal).
Is this normal?
Posted 03 January 2012 - 10:20 PM
The clicks relate to the amount of film transported - 28 frames per click or 7 feet per 10 clicks. The clicks are caused by 3 protrusions spaced around the circumference of the spring motor, which rotates 8 times before coming to a stop. At 24 fps you'll get a click each 1 1/6 seconds. Kinda weird, but that's just how the gearing is.
So a full wind of the spring motor should transport around 670 frames, a bit under 17 feet. At 24 fps you should get about 28 seconds. If it's less, the camera is probably running a little fast.
Posted 04 January 2012 - 02:00 PM
So it must be my frame counter that is off. It only indicates 612 frames per wind.
Posted 04 January 2012 - 06:42 PM