Most studio cranes have strong bases that cannot turn over if there is problem.
Many of the cranes made for DV cameras today are supported on expensive tripods
and pivoted on tripod heads that are rated for much less than the weight of
the arm, camera and counterweights. Many 30 lb. DV cranes are on heads rated
for 18 lbs. These heads will not last long with this abuse.
There is no need for fluid dampening at the center post bearing of a crane.
The inertia of the arm provides smooth moves.
Some tripods are safe for supporting a lightweight crane, some are not. The
tripod legs must lock off much better than needed for just a regular head and
Tripod legs have to be attached to one another or be securely attached to the
base so that if one leg is lifted the whole tripod won't collapse. Center column
model tripods with braces to the legs are good. If the legs are only held by
the ground, a triangle, or a tripod dolly, there is a great danger if one leg
I don't trust most of the triangles and tripod dollies out there to prevent
the leg from coming loose.
Worse yet are tripod dollies with tall caster wheels. They raise the contact
of the tripod above the ground and the ability of the wheel to caster puts the
tripod leg over air when moving in one direction. Making a dolly and crane move
with this kind of dolly is folly. A dolly can be helpful for finding the best
place for the "center post" of a crane, but the dolly has to be very
stable. If the dolly is larger than the tripod stance, it will be safer.
Some light and grip stands that that have a center column braced to each leg
can be modified to support a lightweight crane. They are stronger and more rigid
per pound of weight. If the stand relies on legs supported only at the bottom
like the regular grip "C" stand, they are not rigid enough. Most light
and grip stands are not designed to support a moving weight up high. They are
designed to be compact when folded. Some loud speaker stands are strong enough
for very light weight cranes, but have no leveling leg feature for use on un-level
Leveling heads are acceptable only if they lock off well and do not raise the
pivot point of the crane arm much above the top of the tripod. If the crane's
pivot point is to far above the top of the tripod it can tip over easily. (This
is true for heavy camera too.)
Attaching a lightweight arm to a tripod head or center post bearing can be
challenging. I have found that a strong pin attached to an arm dropped into
a tight fitting socket on the center post/pivot/support works very well as a
bearing. Simple, safe and easy to assemble.
Larger studio cranes with strong bases have brakes for the vertical arm moves.
Locks on lighter weight cranes on light weight bases can be dangerous because
the torque of the arm can lift a leg off the ground or out of a socket or tip
the whole base over. Locks on studio cranes and camera cars should be off while
shooting and moving to allow for inertial stabilization and ability to move
the arm out of danger's way.
The ability to level the tripod/post on non-level ground is important. Any
stand without a leveling leg would be a compromise. Wedges and blocks under
a leg are not safe. Leveling a crane arm with a leveling ball joint on top of
the tripod is dangerous because it puts too much strain on the leveling ball.
These heads are designed for cameras and tripod heads only. "Rocky Mountain
Legs" on light and grip work very well to level the stand. Heavy Mitchell
type levelers with large screws are strong enough.
Weight added to a post/tripod/stand can help prevent the post/base from turning
If you use a tripod head for the center pivot, use a pretty big head to prevent
damage to that head. The head can be damaged by all the weight and torque. This
also raises the cost of a system. Using a tripod strong enough to be safe can
cost much more than a simple arm. Using a dedicated support only for the crane
can be cheaper and safer. Old style reflector stands and some grip or light
stands with braces from the legs to the center column are good solutions for
© Copyright 1999-2004 Ron Dexter. All Rights Reserved.