I'm researching the rough cost of building my own camera crane. Based
on my calculations, I need approximately 1800 pounds of weight to
counterbalance the arm at its maximum length. Since the arm length is
variable, the weights need to be in 100, 200 or perhaps 300-pound
blocks so some of them can be shifted back and forth. I looked into
steel, which is almost 500 pounds per cubic foot (fine for my
purposes) but I can't get any local quotes for solid blocks of
steel... I'm looking to balance cost with the efficiency of the
material - i.e. I need something in the lowest price bracket for raw
materials, but it's OK to pay a little more if the material nets me
considerably more weight for smaller dimensions. So, what would be
some good materials, and where would I go to get them? And since we're
in that general area, do you have any recommendations on materials to
build the structure of the crane out of? It needs to be as light and
as strong as possible.

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Request for Question Clarification by denco-ga on 18 Aug 2005 19:16 PDT

Howdy sexyrexy-ga,

I wanted to see if the following ideas might fit your needs.  It might be
totally different than what you are imagining, so I want to make sure it
is within the ballpark of your needs.

For the framing, boom, etc. of the crane, I think a triangular aluminum
truss system could be modified and turned into what you need.
http://www.theatricalshop.com/rosesweb/truss_systems.htm

For the counterweight, I am thinking that sand bags would be a cheap
route to go.  Easy to fill, cheap materials, can be in 10, 20, 25,
50, 75, etc. pounds sizes, easy to hang and detach, etc.
http://www.mutualindustries.com/truck/html/fence.html

If you like, I could work up some numbers based on the above and post it
as an answer.  It would help to know the weight of your camera, the size
of crane you want, does it need to ride on a track or have tires, does it
need to hold a person, or would you want to work the camera from the ground,
and your overall budget.  Any details would be good.  Thanks!

Looking Forward, denco-ga - Google Answers Researcher

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Clarification of Question by sexyrexy-ga on 27 Aug 2005 16:39 PDT

My concept designs are for a crane that can telescope from 12ish to
20ish feet. In most cases the crane would be on wheels, but it would
be nice to have the base flexible enough to set on tracks (provided
they can support the weight). The head of the crane would need to
sustain the weight of a remote head, which supports a largish camera,
cabling, and various miscellanious equipment.  Probably no more than
60 pounds total, ever.

Sandbags would seem to be impractical, as the weight needs to be
shifted back and forth very precisely by motor as the crane
telescopes. I've designed a PCB (printed circuit board) and started
writing some software that will control the motors that move the
telescoping segments and the remote head. Ideally I want to be able to
set up live input controls, or program sequences of motion into a
computer so that the action can be repeated with precision. (Perhaps
someday down the road even record a live sequence via sensors and then
repeat that.)

I realize this is a very ambitious project, technically and
financially :-) I don't have an exact budget, but I have a couple
thousand dollars that can be put towards it, and I can probably get
some more if necessary.