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Old February 29th, 2004, 03:37 PM   #1
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Proper glidecam weight

I'm having difficulty balancing my new glidecam 2000 with my vx2000. It lifts straight up when I pick it up from a table but seems to "get away" from me while walking with it. I am stabilizing is slightly with my forefingers and thumb which works, but I'm not sure is a recommended technique.

Is there anyone else that uses a vx2000 with a glidecam 2000 that could possible take a picture of their set-up or walk me through a detailed guide on how many counter-balance weights to use and at which angle. I was amazed that something so small as opening the side viewing window on my camera caused the glidecam to tilt -- is this normal? I want to minimize all possible problems on the days I'll be shooting this summer.

FYI - I am balancing the cam with all the usual stuff on it for better accuracy.

Any help anyone can give me on properly using the vx and the glidecam would be greatly appreciated! :)

Thanks in advance!
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Old March 1st, 2004, 10:44 AM   #2
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When you balance it, balance it as you would use it, ie, screen open, open shutter,, mike accessories set, everything. There are many threads in Support your Local Camera.

Yes, the GC does require your fingers and thumb to balance as it was not designed to fly just holding the grip. If it is getting away from you, check your drop time. A less than 2 second drop from a horizontal position (holding onto the grip, right ;) ) would make it hard to control. If you get closer to 3 seconds, it will be a little easier to control, but it will have momentum that you need to account for.

This takes awhile to learn. I mean weeks, not minutes. You have to learn the motion and then learn to adjust for it. Totally new motor skills.
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Old March 1st, 2004, 12:46 PM   #3
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George,

I find that mine is twisting one way or the other. Is this a balance issue or just lack of experience with it?
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Old March 1st, 2004, 01:02 PM   #4
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Brian, twisting on which axis? Does the motion look sort of like the deck of a ship at sea with a swell? Sort of a pendulum? The "ship in the sea" pendulum motion is experience for the most part. What does it do if you turn the camera to your left or right? I found that you could balance it front to rear, but have the lens to back center too far back or forward on the true center of gravity. That would result in the camera tilting when you "spin" it on the bearing part of the GC. If you turn it 90 degrees left or right, does it pick up a heavy lean? You may need to find a different hole on the base plate. CAREFULLY (not to drop it) try to find where the center of gravity of the camera on the base. I "balanced" my camera on my finger like a basketball (of course, I did not really let go) to find that point. You need to have it rigged as you are going to "fly" it when you do that. I then put that point of the camera as close to the center of the pole on the GC to start.
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Old March 1st, 2004, 01:16 PM   #5
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Mine isn't listing one way or the other like a ship, but panning to the left when i pick it up
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Old March 1st, 2004, 02:14 PM   #6
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George is correctly describing the need for dynamic balance as well as static balance. Joe, it does sound like you have a problem, in that you are suggesting that the rig pans by itself without operator feedback. This could represent an issue with the gimbal. To confirm this, mount the rig on the docking stand with the gimbal on the pin so that it swings free, and fine tune your balance. Does it still pan by itself? What happens if you gently pan the other direction, does it come to a stop and reverse direction? If so, there is an issue with the hardware. Otherwise, it's a dynamic balance tweak as George described, or possibly operator error.
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Old March 1st, 2004, 02:39 PM   #7
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Thanks for the help there, it was a balance issue. Balanced properly now. Man..... I can imagine the shots you can do once you've mastered this thing.
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Old March 2nd, 2004, 10:51 PM   #8
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A less than 2 second drop from a horizontal position (holding onto the grip, right ;) ) would make it hard to control.

George, what do you mean by a "2 second drop from horizontal position"? If I lift it up and stand there is is completely vertical and doesn't drop....looks straight ahead.....is it supposed to "drop" a bit? I may have it right...I just have to practice with it more. It does seem like the "Ship swaying" phenomenon to me...I wasn't sure if that meant I had too much weight or not enough weight on the bottom...
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Old March 3rd, 2004, 06:28 AM   #9
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Drop Time - It is described in the instructions. You hold the handle and swing the base up with one hand so that it is level with the camera. Let go and count. The time it takes to swing from the horizontal to vertical is the drop time. The base needs to be heavy or light enough for this to take 2-3 seconds. Also, you can use the knob adjustment to lengthen or shorten the pole to get yor drop time in this range.

Once the GC is balanced, the swaying is operator error. Here is where it takes time to learn to fly the rig. ;)
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Old March 3rd, 2004, 07:56 AM   #10
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Has anyone tried drilling holes in the top and bottom of the post and threading the video cable through it? I remember Casey Visco mentioning that once, but I just wonder if anyone has done it and if there are any considerations...for instance, do the drilled holes have to be absolute dead center?
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Old March 3rd, 2004, 08:56 AM   #11
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Quote:
Drop Time - It is described in the instructions.
George,
It is interesting that drop time is not mentioned anywhere in the manual I got with the 4000 Pro, nor on Glidecam's website. However, having done a search in this forum, I got information I needed to establish a 2-3 second drop time. Now that I have that, is it uncharacteristic for the rig to meander around when being held without any motion (it evenually stabilizes)? I believe I have established good side-to-side and front-to-back balance, but with little weight on the base, I have to stablize the rig with my guide hand. Is there a quick check for dynamic balance?

BTW, my rig is the GC4000 Pro, a Panasonic DV953 attached to a Manfrotto quick release with spirit levels on the sled, and no weights on the base. I know that the sled weight is at the low end rating for the 4000 Pro, but I'm anticipating additional weight due to accessory lenses, larger battery, LCD hood, mic....
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Old March 3rd, 2004, 01:50 PM   #12
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Guy,

At such a light load, you are very dependent on the precision of the rig, particularly the gimbal, to maintain level without wandering as you described it. The more weight, the greater the inertia, and even though you might have exactly the same drop time with a rig that weighs twice as much you will notice a much "quieter" frame. It may be worth going back to a faster drop time to overcome some of this. In a perfect world, the rig will just sit there and not start to rotate or tilt by itself. However, imperfections in the gimbal may translate a certain percentage of your hand movement (the one supporting the rig) through to the sled, which will seemingly start to move by itself. One way to test this is to place the handle in a table-mounted clamp of some sort to allow it to float freely without you having to hold it and see if that makes a difference. Chances are you will see it settle down and stay that way in this circumstance. Bottom line is that you will always have to have the guide hand working when operating, and you will end up automatically "dialing out" these tendencies as a matter of course.

The dynamic balance check requires spinning the rig in the pan axis and watching to see if it starts to precess, i.e. the nose dips or raises consistently as it goes around. Ideally the camera should stay level at all times. If you have that above-mentioned clamp system (sorry, I don't know if the 4000 comes with any kind of balancing setup? Casey?) it will be a lot easier on your wrist to use that! Since you are not using any sled weights, you don't have much to work with to adjust, but that also means that you are unlikely to be far out in dynamic anyway.
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Old March 3rd, 2004, 05:03 PM   #13
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Charles,
Thanks. That helped. I get very little precession...at least within my ability to impart spin without making the rig precess. When I spin it right, the rig spins and precession only slightly occurs just before the spin stops. I also shortened my drop time by increasing the length of the shaft. It is still pretty close to balanced because when I do my drop test, the rig swings almost horizontal to horizontal and takes a long time to come to vertical and rest (many oscillations).

Again, thanks, both for your response to this post and for you and all the others who have supplied valuable information in this forum.
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Old March 3rd, 2004, 06:24 PM   #14
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It is the first drop to vertical that counts when you test the drop time. All the rest of them after that show that the gimble and bearings are high quality :)
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Old March 3rd, 2004, 07:29 PM   #15
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Guy,

Like you, I'm in pursuit of optimum balance with my Glidecam and I've gotten pretty good at it...but part of that pursuit entails trying to get rid of all "dangling" things or things that have to be wrapped or tucked in ever differing ways such as the video cable leading from the camera to the monitor.

I'm suprised no one has chimed in here about whether they've threaded the cable through the sled post (requiring drilling two holes). Casey Visco, an employee of Glidecam, mentioned that in a previous thread. But I've yet to hear any followup on it.. particularly success stories of people who've tried it themselves.

It seems, in theory, to be a good idea. Centralizing as much of the weight as possible can only improve balance.
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