Nervous about camera falling off...
Posted 08 April 2012 - 10:56 AM
I am very new to the Steadicam world. I have taken two 2-day courses (totally worth the time and money investment) and recently purchased a rig. I have been reading the boards a lot and can't seem to find the answer to my particular question. It is possible I am using the wrong terms, if I am I apologize for this posting. I found when I am building my rig I am very nervous about the 20lb camera being held onto the top stage of the rig by a single screw, especially in low mode. Is there something I am missing. I never thought to ask my instructors about this at all. Is this fear silly? Did I miss something and there should be more holding the camera to the plate? Thanks again in advance for the help and I appreciate you taking the time.
Posted 08 April 2012 - 11:26 AM
In general, I think 20lbs is pretty hefty for a single camera tie-down screw, and you may be placing a camera on that rig that is at the top of the weight range intended for that sled?
Posted 08 April 2012 - 11:57 AM
3/8-16 grade 2 has 5,875 lbs of tensile (breaking strength) which means it's working limits are 510lbs at thread root for shear, 830lbs shear in the middle and 410lbs of pull strength. Move up to a grade 8 bolt and those number go up by 80%
If you are using a 1/4-20 those numbers are 200 370 160 and again +80% for grade 8
If you'd like to learn more about fastners read this link
Posted 08 April 2012 - 12:00 PM
Eric brings up a good point, get good screws. One reason to always buy them from a Camera place. Sure, they overcharge a little but you have a receipt which says they are meant to be used for that.
Posted 08 April 2012 - 03:14 PM
Posted 08 April 2012 - 03:15 PM
Posted 10 April 2012 - 09:17 PM
The screw thread will fail if you let it comes loosely.
Usually I will tie the camera on the mount with a cable tie when use it on a jib for safety precaution, because it will fly over peoples. But I don't think you need to worry on a steadicam