Pilot Dynamic Balance

[Robert Starling SOC]

Right way, wrong way is irrelevant. You use whatever method the works for you and your rig in the shortest time with the least hassle possible.

 

I demo both methods when I teach and then let the student decide.

 

Personally with my specific rig I use the neutralized set it and forget method on my sled / monitor / battery combination. But that may not work with every sled.

 

This topic has been discussed ad-nauseum on the forum and there's enough information in the archives to dull anyone's senses.

 

Personally I don't know and don't need to fill my brain with the technical and mathematical theory behind it all; I just need to be quick, simple and moving on.

 

Robert

[Jerry Holway]

Right way, wrong way is irrelevant. You use whatever method the works for you and your rig in the shortest time with the least hassle possible.

 

I demo both methods when I teach and then let the student decide.

 

Personally with my specific rig I use the neutralized set it and forget method on my sled / monitor / battery combination. But that may not work with every sled.

 

This topic has been discussed ad-nauseum on the forum and there's enough information in the archives to dull anyone's senses.

 

Personally I don't know and don't need to fill my brain with the technical and mathematical theory behind it all; I just need to be quick, simple and moving on.

 

Robert

 

Robert-

 

I agree with with all you say, and with Neal.

 

No one has to fill their head with the technical and mathematical...

 

But problems arise when BS and voodoo is touted as truth, and then someone - like Arnold DiGuilio, Ed's brother – must come along and do the math and the rest of us must do the empirical testing, as Neal did. The methods must work in all cases, and be repeatable, and not just in a unique-to-some-rigs case with the monitor at the same level as the battery, like the Model One or the XCS or the Baer-Bel.

 

Of course, once anyone gets their rig into dynamic balance, and makes a couple of marks, and doesn't change the configuration, he/she never needs to change anything.... unless the operator does change something, as many operators do, for the benefit of the shot. Then the empirical methods that work in all cases are really useful, and a general understanding of what is really happening can make the process faster and more simple.

 

Regardless, it's not a big deal. Some suggestions for anyone having difficulty: Spin balance at regular panning speeds. Use a normal drop time or slightly faster/more bottom heavy. Light rigs with long drop times can be very touchy.

 

Jerry

[Douglas John Kropla]

ok man... I'm a newbie myself but i feel there is a lot of misinformation going around... people are feeding pieces of infromation but you need to understand them as a whole to grasp the concept of dynamic equimibrium quickly and effiently.

 

the steadicam pilot video everyone is posting is decent instructional video but doesnt really "teach" you how to get any closer to achieving balance without a bunch of trial and error.

<<SNIP>>

 

 

 

 

Close but no cigar, you are STILL making it to difficult.

 

Why is everyone so damned concerned with finding the CG of the camera then placing it 1/2" behind the center of the center post? in the last 10 years that I have be using my "90 Degree Drop" method of dynamic balance i have NEVER ONCE "found the CG of a camera" before I built the rig much less used a freaking ruler.You are creating work that gains you NOTHING.

 

Here's what you do:

 

With nothing mounted to the camera stage, (no follow focus, no camera, no camera plate, no cables) Lay the rig on it's side and balance the batteries and monitor until the lower section is balanced so that it neither rolls to the monitor or the batteries.

 

Build the camera to the rig with all the accessories that you are going to use find a rough side to side on on the built camera and mount the camera to the Camera Mounting plate

 

Put said camera on the Upper camera platform (Stage) and mount the accessories that you normally fly off the stage (MDR, Preston interface)

 

Set a 3 second drop time (which is a proper drop time for most work)

 

Balance the stack side to side (using the stage adjustments)

 

Balance the stack to hang level fore and aft with the camera mounting plate in the stage (you did zero the stage to it's center position before you started this, Right?)

 

Spin the rig and Guess what?

 

You are in dynamic balance. It took all of 60 seconds to do it. Want to double check your work? Bring the post up to level, pan it 90 degrees so that the batteries and monitor are level to the floor and drop, everything should stay in place, the post should not rotate as the gimbal rolls to level.

 

oh and guess what again.... You will NEVER have to change your dynamic balance again, you can put any payload on the top, adjust for a 3 Second drop and the rig will STAY in dynamic balance FOREVER

 

I dynamic balanced my XCS Ultimate when I bought and have never done it again. People who claim that this is rocket science are wrong

 

I cannot begin to tell you the number of people I have taught this to in the last few years that have looked at me and said "Really? it's that simple" as their rig is sitting there spinning flat all day long.

 

Hey, I have done this kind of balance trick from the beginning, didn't know that it was Eric's 90 degree method. Just seemed to make sense at the time and it really is a quick way of determining dynamic balance.

[Joe Lawry]

 

With nothing mounted to the camera stage, (no follow focus, no camera, no camera plate, no cables) Lay the rig on it's side and balance the batteries and monitor until the lower section is balanced so that it neither rolls to the monitor or the batteries.

 

 

 

Eric, can you confirm how you are doing this? gimbal handle on the balance pin of your docking bracket, without a 'mickey'?

 

Everything else makes perfect sense, but this first step in my mind needs some clarification.

 

Cheers

[Ryan Rodinis]

 

With nothing mounted to the camera stage, (no follow focus, no camera, no camera plate, no cables) Lay the rig on it's side and balance the batteries and monitor until the lower section is balanced so that it neither rolls to the monitor or the batteries.

 

 

 

Eric, can you confirm how you are doing this? gimbal handle on the balance pin of your docking bracket, without a 'mickey'?

 

Everything else makes perfect sense, but this first step in my mind needs some clarification.

 

Cheers

 

Yes - use something to hold the sled on its side (not going to be frictionless without something like the mickey), with the monitor/batteries parallel to the floor. I imagine you can get close enough with just the side of your index finger. I used this method twice this week with good results.

 

What boggles me is that, if I swap a lens and adjust the stage for fore/aft, I don't need to adjust the battery as I'll still be in dynamic balance, correct?

[Eric Fletcher S.O.C.]

Yes - use something to hold the sled on its side (not going to be frictionless without something like the mickey), with the monitor/batteries parallel to the floor. I imagine you can get close enough with just the side of your index finger. I used this method twice this week with good results.

 

What boggles me is that, if I swap a lens and adjust the stage for fore/aft, I don't need to adjust the battery as I'll still be in dynamic balance, correct?

 

 

I think people are getting hung up on gimbal height and the lack of neutral drop time without a camera. All you need to do is be able to let the post rotate in the gimbal when held horizontally. Balance the batteries and monitor so there is no rotation. Pan the post 90degrees to make sure that the monitor ismbalanced left right (This is where Jerry is getting his wobble) and then mount the camera to the upper stage. When you have the camera balanced fore aft and left right the rig will spin flat, all the masses cancel out. You can the change lenses or hell you can change camera, as long as you don't change the location of the monitor and batteries your rig will always be in dynamic balance

[Alfeo Dixon SOC]

Maybe besides explaining your method in plain text you can explain your method with a small video also?

 

 

Sure let me get right on that in all my free time....

LMAO!!!

[Alfeo Dixon SOC]

Tiffen introduces the New Balance Brick (BB-1) for dynamic balancing... Just slap this puppy on your topstage to help with those awkward balancing situations!

 

[Fabrizio Sciarra SOC ACO]

Tiffen introduces the New Balance Brick (BB-1) for dynamic balancing... Just slap this puppy on your topstage to help with those awkward balancing situations!

 

 

Finally. This should seal this thread forever and after.