Tuning Your Steadicam Arm

Friday, January 14th, 2011

I can remember it like it was yesterday. I was in a Steadicam Operators Association Workshop listening to Peter Abraham talk about tuning the arm. To paraphrase, Peter’s take on tuning the arm consisted of tweaking the lifting force of each section until the two sections bottomed out simultaneously when you boomed from the top of the boom range to the bottom, and vice versus. This is how I’ve done it now for years. Recently, I purchased a U2 rig with a G70 arm. The G70 is a fantasic arm. It has a phenominal boom range of 32″, and it has a rather clever adjustment for iso-elasticity which allows you to change the ride of the arm. There are some cons to this arm. Perhaps the most significant is the friction inherent in the arm. The friction results in the “bobble” in the boom we try to avoid as operators. So I’ve been re-examining my approach to tuning the arm.

When it comes down to it, the arm was designed to function very similarly to the human arm. This is why systems such as the Merlin do not require an arm… you just use your own arm! In fact, the human arm is more than likely much better than any arm on the market. The problem is (of course) that we can only lift a small amount for an extended period. So I started playing with the G70 arm…tuning it down so that it still acted in the way Peter taught me, but with the lifting force just below what was necessary to lift the load. Basically, if I let the arm go it will immediately bottom out.

The goal here is to include the human arm in the equation… so that we aren’t just holding the arm at a particular boom height, but rather lifting slightly. This way, the friction of the arm doesn’t play as important of a roll. When I tried this, I was pleased with the results. Of course it means more work for your right arm. However, I have found that it reminds me to make specific choices with the boom height. I like that!

In addition, if we look at the act of “booming down” we see that causes us to lean forward ever so slightly. We of course can offset this by leaning back ever so slightly. However, if we tune the arm down slightly… booming down is “automatic,” but of course booming up requires more force than previously required. This doesn’t bother me too much. It may, as in booming down, cause me to lean back slightly as I boom up… but I’d much rather be forced to lean back slightly over leaning forward.

Update: “Tiffen is now offering an upgrade to the G70 arm which consists of changing the lower end blocks of each arm segment, replacing components in the ride and lift assemblies along with changing bearings in the ride and lift assemblies to a new style. The upgrade costs $2500.00 and can be completed in two business days.”

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