Setup my pilot with XH-A1 and WD-H72, few questions

[Julian Frost]

Originally Posted by Dave Gish

Huh? Increasing the stage weight should always move the CG toward the stage, which means you have to move the gimbal up to maintain the same drop time.

True... but if you increase the weight at the top, you also decrease the drop time. To overcome that, you either have to lower the gimbal (which is the opposite of what we're trying to achieve), add weight to the bottom spar (which neutralizes the weight we just added!), or increase the center post length. The last option may work, but can add to the sway we often see. I know I'm not telling you anything you don't already know. :-)

Where do you add the stock weights? Do you use a QR plate? Any other accessories?

All my weights are on the bottom spar. I use the wide angle adapter, a QR plate, and sometimes the FS-C. Generally that's about it.

Julian

[Dave Gish]

Originally Posted by Julian Frost

...if you increase the weight at the top, you also decrease the drop time. To overcome that, you either have to lower the gimbal...

The CG always moves toward increased weight. Adding weight at the top will INCREASE the drop time, or perhaps invert the rig. To overcome that, you have to RAISE the gimbal (move it toward the stage).

Originally Posted by Julian Frost

All my weights are on the bottom spar. I use the wide angle adapter, a QR plate, and sometimes the FS-C. Generally that's about it.

From what I've found on the internet:
• XH-A1 = 4.5 pounds
• XH-A1 normal battery (BP-950) = 0.5 pounds
• wide angle adapter = 1.5 pounds
• QR plate = 0.5 pounds
• FS-C = 1 pound (not sure about mounting plate)

All together that's 8 pounds, which works great for me. If you leave something off, you'll probably want to add weight up top.

Here's what I would try:
• On the bottom, w/IDX batt, 2 mid weights on each side, no matter what you have on top.
• On the top, without the FS-C, and with the wide angle, 2 mid weights on each side
• On the top, with the FS-C, and with the wide angle, no weights
• On the top, without the FS-C, and without the wide angle, 4 mid weights and 1 end weight on each side.
• On the top, with the FS-C, and without the wide angle, 3 mid weights on each side.

Hope this helps.

[Randy Panado]

Hey Dave,

It took about 45 minutes, but I got the rig both DB'd and SB'd with your settings. I had to adjust the stage almost ALL the way back to get the CG behind the gimbal. That's what took the longest as once I realized what direction to go to get the DB spot on, it went rather quickly. Drop time is at about 1.5 secs with the telescoping set at 1 inch. I suppose if it was a problem where I ran out of adjustment room, I could have simply subtracted one mid weight from the front of the stage to compensate?

Thanks so much :)!

I'll be using the lower monitor for better posture from now on. I haven't got a chance to fly it yet as it's late here so I'll save that fun for later today.

-Randy

[Amedeo Fabroni]

Another way to raise the gimbal high on the post near to the stage, is to add customized metal weights distributing the masses to obtain an higher CG (camera + weights). For example if you want to add 2 pounds you can make a simple metal plate or a cage. With the cage you will able to obtain an higher CG (with top and bottom same plate thickness) but you can also raise the CG making the top plate of the stage more thick than the bottom one. To maintain the same drop time you’ll have to raise the gimbal.
Amedeo

[Dave Gish]

Originally Posted by Randy Panado

...I got the rig both DB'd and SB'd... Drop time is at about 1.5 secs with the telescoping set at 1 inch.

A 1.5 second drop time is probably too fast, especially to start with. The problem with a fast drop time like this is that the sled will want to swing a lot when you start, stop, or change directions as you walk. A very experienced operator can compensate for this by feathering out the starts and stops with the left hand, but this takes years of experience to perfect. For a beginning operator, a 2.5 sec drop time will probably work much better.

Originally Posted by Randy Panado

I suppose if it was a problem where I ran out of adjustment room, I could have simply subtracted one mid weight from the front of the stage to compensate?

I've tried this and it didn't work out well. It always seems to work best if you add the screw-on weights evenly to both sides. If you run out of adjustment room, it's better to move the camera back on the stage. Here's an example of the camera moved back:
http://www.dvinfo.net/conf/attachmen...x1-3-ex3_1.jpg
The QR plate hangs off the back a little, but it seems to work fine.

Originally Posted by Randy Panado

Last thing, when the pilot shoots out after sitting in front of me, what can I fix in my posture or adjust on the vest/arm to have it not be so squirrly?

OK, so now that you have the rig balanced and are using the lower LCD, we can move on.

There are some adjustments where the arm meets the vest. The 2 black wing-nuts that lock the arm to the vest also adjust where the sled wants to sit forward or back. The 2 aluminum eye-screws adjust where the sled want to sit side-to-side. In both cases, most people keep the top nut further out, but this is a personal adjustment, so play around with it. NOTE: The aluminum eye-screws are soft metal - don't over-tighten the nuts, you can easily strip the threads.

But perhaps a more likely reason for the sled getting away from you is your form. The idea is that you control everything with your hips. Move your hips back, and the rig will move forward. Move your hips forward and the rig will move back. For now, just play around with it for a week or so to get the feel of it.

After that, I recommend an intensive week of hands-free training. For 1-3 hours a day, practice without either hand touching the rig. Just use your hips to control the sled position. Keep you hands close to where they will be, within an inch of touching, in case it gets away from you. Turn the camera off. Practice all the exercises in the Flyer manual starting at page 29:
http://www.steadicam.com/images/cont..._Manual_Lo.pdf
After a solid week, you should be able change positions, change speeds, etc., all without touching the rig. I feel that being able to balance the rig with your hips like this is the most important aspect of operating a steadicam.

[Julian Frost]

Originally Posted by Dave Gish

The CG always moves toward increased weight. Adding weight at the top will INCREASE the drop time, or perhaps invert the rig. To overcome that, you have to RAISE the gimbal (move it toward the stage).

Dave,

You are, of course, right. I was thinking INCREASE, but wrote decrease, then I started arguing both sides! Hahaha! I must get more sleep.

All together that's 8 pounds, which works great for me. If you leave something off, you'll probably want to add weight up top.

Your weight calculation sounds about right. I've not used the rig fully loaded in a while, but I remember during running shots, seeing a distinct vertical bounce, more like a vibration, when it was fully loaded. That was something I didn't see in footage which was shot with a less than fully loaded rig.

When I next get a chance, I'll try adding the weights to the top stage again, like you suggested. I remember trying it before, but not being happy with the results for some reason. I'll let you know what I find out.

Julian

[Randy Panado]

Dave,

I practiced today for about an hour with hands free operation. You were spot on that it was my form causing it to shoot out. I was able to do some walking around with no hands and keep it relatively close to me. Can't get it right all the time but got the basic concept and see how hips are very important to control.

Just purchased the handbook as well. I'm actually having quite a bit of fun practicing and learning. I've been doing the 30 second lock-offs as well to practice that skill in between hip training before starting a moving shot and after.

Thanks again for the advice!