Update September 2013: What started as a hobby has turned into something pretty serious. We are readying the launch of an open-source cinematic motion-control rig. If you wanna stay up on the futue of cinematography "like" us at facebook.com/openmoco

instructables.com/id/Ball-Bearing-Jib-Arm-w-Motorized-Pan-Tilt/

Basically there are four components to the jib arm, listed in order of difficulty:
Rotating Base (mounts to tripod or other mount)
Camera mount (with or without the Meade Telescope arm)
Counter Weights
Jib Arms

Rotating Base includes:
-1" Horizontal Bearing (Pillow Block)
-2 shaped aluminum 3/8" plates connected by stand-offs, the bottom plate is threaded for the tripod, the pillow block bolts to the top plate,
-1" Stan-offs,
-Welded Steel Fork made from 3/8"x2" steel flat stock. The fork is bolted to the pillow block.
-Bronze Bushings which insert into the steel fork. These bearings are for the up/down arm movement (this is very important)
-Various spacers, washers, bolts.
Bearing Mount:
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Fork:
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Camera Mount includes:
-Aluminum c-channel with bronze bushings inserted. The inside gap needs to be the same width as the gap between the steel fork. My gap was 2".
-Piece of aluminum angle bolted to the c-channel. The camera or pan/tilt head will mount to this.
-Various spacers, washers, bolts.
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Counter Weights:
-Basically a stock weight lifting dumbbell. The handle of the dumbbell splits apart. I drilled a 1" hole in tail of the top jib arm and feed the dumbbell handle through it.
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Jib Arms:
These also have to have bronze brushings inserted wherever a bolt will pass through (so there is no steel on steel friction). The size and length of the arms is up to you. It all depends on your design. Mine are 7' long. Both are aluminum square tubing, the top is 1.5" wide and the bottom is 1".
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