Tips from Thanh Le

 

1. Antlers are basically a set of brass weights on a "T" shaped aluminum bar that attaches to the top of the camera. When installed they looked like, well, a set of antlers. Their purpose it to increase the rotational inertia of the rig in either one or all of the 3 axes. The inertia of something increases with the square of the distance a mass is away from the CG so a little distance goes a long way.

2. Here's some helpful info I found on the Steadicam Forum. The arm bearings in the CP Model 3 arms are apparently Torrington GB-57. These are full complement needle roller bearings, extra precision class. They don't have an inner race so the shaft rides directly on these needle rollers. This shaft must have a surface hardness of 58 HRC (Rockwell C) or equivalent. From my Torrington Service Catalog, the data for the regular version of this bearing (B-57) is:

Bore - 5/16"
O.D. - 1/2"

Torrington Basic Dynamic Load Rating (Cr): 905 lbf
Basic Static Load Rating (Co): 1770 lbf
Working Load (max): 1040 lbf

Normally you have to do some more calculations with these numbers to properly size the bearing, but if you just find an alternate bearing with comparable numbers I guess you should be fine. If you want to copy the 3A exactly these are the bearings to get but you'll still need some thrust bearings or washers because needle bearings carry no thrust load. Personally I don't like needle bearings and would use ball bearings instead, but that's just my preference. Ask 5 engineers how to do something and you'll get 50 different answers. Anyway, hope that helps someone!