Wheights for pilot & Xh-A1

[Dave Gish]

Hi Sam,

 

Notice that I lengthened my post a bit for added inertia, and the top of the gimbal is still 2.5" from the bottom of the stage.

 

Have you weighed all your stuff? How much weight do you have up top? What is your drop time?

 

I flew the EX1 on a couple of student films, and I always had 2 weights up on either side of the stage. That was with a wireless video transmitter, Manfrotto QR plate, and wireless audio receiver.

[Afton Grant]

These are not "theories" or "beliefs" we're talking about here - they're laws. It's simple physics. That's what I was clearing up. The gray area is how do we apply those to what we do?

 

One of the more common mistakes I see lesser-experienced operators make (and I too did this at one point in my career), is try to boil down the setup and operation of the system to clear-cut, on-paper rules and steps. Since cameras, batteries, cables, etc are all oddly shaped objects rather than perfect cubes and spheres we mount on top of sticks, the rules can only help us so far. The smaller the rig, the more effect every single component of that rig has on the system, and when we're dealing with rigs as small as the Pilot and Merlin, even a differently placed cable can change the whole equation. How do you find the CG of a cable that is 3 feet long and snaked in, out, and around a camera? This is why those cookbooks and physics equations can really only be guidelines. If they are taken as such, your experience will soon grow and you'll find yourself setting up rigs with far greater ease. A measuring tape and a scale will only aid in further confusion.

 

I prefer a gimbal that is about 2 inches below the stage (I say "about" because I've never really measured). ...but I also prefer a shorter sled length ...and to fly one big battery ...and have my DVR on the bottom ...and many others. I don't always get my way with every single thing.

 

Sam's point about Garrett's gimbal and Charles's weights was spot on. And it doesn't mean their configurations were the "right" or even "better" configurations. They were simply what they each chose to do.

[Eric Fletcher S.O.C.]

A few things guys.

 

This thread is starting to look like a horse that has been severely beaten to death.

 

Static Balance, Dynamic balance and the ways they work are not theories like Afton pointed out. They are laws and the basis of HOW the steadicam works. It seems that the less experienced in this discussion are having trouble with the foundation of what a steadicam sled is. It is a device to "Explode" a cameras polar moment of inertia in all three axis and then access said cameras Center of Gravity by means of a three axis gimbal.

 

No Voodoo, no magic, just physics.

 

Mass X (the camera) is precisely counter balanced by mass Y (The batteries) and Mass Z (The Monitor) that reaction point (The center of balance) is then accessed by a gimbal with it's center of rotation approximately 3/4" below the CG to provide a slightly bottom heavy feel (Although there are some of us that operate a neutral rig with close to infinite drop time.)

 

The only true way to balance the rig is to do it empirically and not via a "Cookbook"

[Dave Gish]

The only true way to balance the rig is to do it empirically and not via a "Cookbook"

Yes, I agree. Dynamic balance is very empirical, and there are no cookbook solutions.

 

But the Pilot has these screw-on weights, and since the Pilot is so light, you really want to use these weights to increase stability. So the question often asked is: How many of these weights should be added, and where?

 

Adding more weight increases stability, and this is particularly noticeable on a very light rig like the Pilot. The Pilot has a 10-pound rated weight limit, but there is some buffer here, so many Pilot users add enough screw-on weights to get right up to the 10 pound limit to order maximize stability. This way, the weight is essentially the same for all the various combinations of cameras and accessories that work with the Pilot.

 

The next question is: Where should these weights be applied? Adding more weights to the stage moves the gimbal closer to the stage. Adding more weights to the bottom crossbar increases inertia, especially in the pan axis. So there is a trade off here.

 

After experimenting with this for a year and a half, doing various student films, low-budget music videos, and industrials, I've come up with a cookbook solution for how many and where to add these weights that works best for me. I've recommended this recipe to many new Pilot users on the forums with positive results. Basically, I add enough weights at the stage to get the top weight up to 8 pounds, and enough weights to the bottom to get up to 2 pounds. This has worked well for all the cameras I've flown on the Pilot, regardless of the weight of the camera and accessories.

 

I realize that my experience pales in comparison to professional operators, but I believe the Pilot screw-on weight issue is somewhat unique, and I am hoping my experience in this specific area might be useful to others.

Edited April 21, 2009 by Dave Gish

[Eric Fletcher S.O.C.]

The only true way to balance the rig is to do it empirically and not via a "Cookbook"

Yes, I agree. Dynamic balance is very empirical, and there are no cookbook solutions.

 

But the Pilot has these screw-on weights, and since the Pilot is so light, you really want to use these weights to increase stability. So the question often asked is: How many of these weights should be added, and where?

 

 

No, technique is what actually improves stability.

 

You don't need to add weights except to balance. The rig balances just like a larger rig. The screw on weights are not unique when it comes to balance.

 

You also misconstrue my comment about balance. it is ALWAYS empirical, Static and dynamic

[Charles Papert]

No, technique is what actually improves stability.

 

Technique improves stability of the images produced by the Steadicam. Increased inertia improves the perceived stability of the rig itself, which in turn should make the images more stable. I don't see anything wrong with Dave's statement.

 

And I would also agree that the screw-on weights are unique to the Pilot in that they are sold as standard accessories and can be mounted on either the ends of the camera platform or the ends of the lower spar--I can't think of another commercially available rig of any size that allows that has that particular feature.

 

I guess the horse wasn't quite dead yet?

[Erik Brul]

And I would also agree that the screw-on weights are unique to the Pilot in that they are sold as standard accessories and can be mounted on either the ends of the camera platform or the ends of the lower spar--I can't think of another commercially available rig of any size that allows that has that particular feature.

 

Only the Sachtler Artemis series has so called ´donuts´ of 400 grams to do about the same. Only mounted at the bottom of the centerpost..

i think :unsure:

 

Best, Erik

[Dave Gish]

No, technique is what actually improves stability.

Technique improves stability of the images produced by the Steadicam. Increased inertia improves the perceived stability of the rig itself, which in turn should make the images more stable. I don't see anything wrong with Dave's statement.

 

And I would also agree that the screw-on weights are unique to the Pilot in that they are sold as standard accessories and can be mounted on either the ends of the camera platform or the ends of the lower spar--I can't think of another commercially available rig of any size that allows that has that particular feature.

 

I guess the horse wasn't quite dead yet?

Thanks Charles.

 

I'm definately ready to call this horse dead.