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Old October 12th, 2003, 12:54 PM   #1
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Glidecam V8 Balance

Ok folks, my Glidecam V8 finally arrived a few days ago! I have spent the last two days reading the manual thoroughly (which reads like an 18th century novel). I need some help determining whether or not my Glidecam is properly balanced. Please bear with me as I am about to write my own novel here.

I was able to construct the sled fine. Now, before I actually put on the rig, I just want to make sure that I have my horizontal and vertical balance set correctly, which I am doing using the balancing bracket on a C-stand as suggested. I don't want to start running around and practicing this thing until I know I have it balanced.

I am using a Canon XL1s. Now, I DO have a nice Nebtek LCD monitor, but I figured for now I just want to figure out how to balance the thing with the counterweight disks. Also, I stripped my XL1s of everything, so it's basically just the standard camera package, standard auto lens...no add ons for now. According to the Canon manual, the default package weighs 6 pounds. Therefore, I added three weight plates underneith the camera to make the recommended 9 pounds for my camera.

Left to Right Balance
Ok, so I start working on the horizontal balance. The XL1s is obviously very front heavy and a little left heavy. However, I think I have got the best results from mounting the camera onto the center of the plate, a little back instead of over to the right. Then by adjusting the mid plate with the allen wrench, I can slide the midplate over and back more to compensate for the camera. The only annoying thing about mounting it in the middle, is if you are using a quick release plate, you canít remove the camera as the QR plate adjuster knob rests too close to the weight plates and canít be turned. Kind of annoying as the quick release plate essentially then serves no purpose. As I'd have to take off the camera plate to remove the camera, I might as well just not even use the QR plate and just bolt the camera right onto the weight plates.

When mounted on the C stand, my horizontal balance is pretty good. However, it is hard to tell. The reason is it seems wherever I place the sled a tiny bit off the axis, it seems to float there. If I lighty touch the sled and tilt it a TINY BIT right, it will somewhat stay there. Which makes me think itís too right heavy. However, if I lighty touch the sled and tilt it a tiny bit left, it pretty much stays there too, which makes me think itís left heavy. Again, if I position the sled with my hand to make it perfectly verticle, it stays there and I think its balanced. I am confused a bit because the manual says that whenever you do a tilt or pan, the sled should always go back to perfect verticle when you release. Mine is sort of doing that, but not really. If I make a hard tilt to the right, yesÖthe camera starts to swing back to itís verticle position, but the sled ends up with the top a little bit to the right, maybe 5 degrees or so. (Imagine the sled as a SLIGHT diagonal line going from bottom left to top right). Likewise, a hard tilt to the left will swing back to verticle, but end up a little bit to the left of verticle, 5 degrees. I hope I am making sense. So I am unsure how to correct this problem or if it even is a problem. For all I now this is how itís supposed to work, as long as I move the post verticle and it floats there, am I allright?

For to Aft Balance
Since the XL1s is so front heavy, I moved the midplate back a bit and I had to add more counterweights to the botton. Right now I have 8 weights on the front of the base plate, and 10 weights on the back, with the back weights pushed back a bit towards to edge. With this setup, when floating, the camera stays perfectly verticle and doesnít tilt forward or back. Although I am getting a little bit of what I described earlier with horizontal balance, where if I lightly tilt forward it stays in a lightly forward position. IF I lightly tilt backward, it stays in a backward position. Again, only by 5 degrees or so, so itís almost verticle, but not quite. If I position it perfectly center, it stays there and floats.
The manual recommends only 6 counter weights in front and 6 in back. I found this to not be enough weight when doing a Sled Arc Test. Which leads me toÖ

Up and Down Balance (Sled Arc Test)
I had to use all the disks in order to get enough weight on the baseplate to drop. With all the weights on, it seems as if I have a perfect 3 second drop time. Basically I just lift up the baseplate to horizontal and let go and it takes a perfect 3 seconds for the base plate to return to verticle. So I hope I am all set there.

Do you guys think I am ready to roll? Just want to make sure if what I described is normal, or if I need to do some more adjusting. Also, for those with the V8 and who use the XL1s, what are your personal setups? Where have you mounted the camera, what weights are you using and where those weights are, what type of attachments you are using on the camera (system isolater, MA200, manual lens wireless etcÖ)

Those are all the questions I have for now and Iím sure I will have more. Thanks to anyone who can help with any of this.
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Old October 12th, 2003, 02:27 PM   #2
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Hi Brad,

Welcome to the club :-) My first piece of advice is to balance the system how you're going to use it, so put your XL1 back together and get that monitor on the sled, by not putting it together how it'll be used just means you'll need to rebalance again when you do, and if you're using 6 disks on the front of the sled at the moment you might only need 4 with the monitor attached so you might be doubling the work you need to do to get the system up and running.

You should be able to get the quick release plate to work, what you'll need to do is to tighten the knob until it hits the weight plates, then use an allen key to loosen the screw that goes through the knob, you can then pull it out and turn it back without adjusting the current setting, this means you can set the range from loose to tight to allow you to work round the problem of it hitting against the weight plate(Hope you understood that terrible explanation).

If your system is properly balanced no matter how small an adjustment you make left or right up or down it should return to centre. If it was too heavy to the right then at a complete rest it should be titling to the right, it shouldn't stay where you leave it, the only thing I can think of here is that the sled is still a bit too top heavy so you may need to add a bit more weight to the bottom of the sled or extend the post a little just to allow it to return to centre. Your 3 second drop time might just be a bit too much I found that for me 2.5 seconds worked so this would mean increasing the weight at the bottom or again extending the post.

Hope that helped Brad, I know how difficult this can be, but I learned so much from this forum that I'm sure it won't be long before you're flying :)

John.
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Old October 12th, 2003, 02:53 PM   #3
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Thanks a lot John for the quick response and advice. That's a good tip about the workaround for the quick release plate, I will do that, and yes you're probably right I'm wasting my time if I'm not balancing for what I will be using. I'm going to add on the monitor. As far as the balancing, I think later tonight I am going to make a video and upload it to show you guys my rig so far, though I will try adding more weight because that might help with the horizontal balance. If that doesn't work I'll post a video and maybe you guys can get a better idea of why it isn't staying verticle. Thanks again John, I'm excited about this thing and hope I have the patience to make it work.

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Old October 12th, 2003, 04:26 PM   #4
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" ...I'm excited about this thing and hope I have the patience to make it work. "

That's one of the keys to getting good shots - Patience ;)
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Charles
'What we perceive to be may not be what we believe to be.'
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Old October 12th, 2003, 05:44 PM   #5
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Charles, true that. I am the king of patience. Just as long as I am able to become a glidecam master by tonight all should be good. Otherwise, it's going to the junkyard. ;-)

Ok, now I have opened up another problem. John, I attached my Nebtek 5" monitor to the front of the baseplate. Along with the battery for the monitor attached, it adds a considerable amount of weight and my sled tips forward at a fast rate. In order to achieve a for/aft balance, I had to add 16 weight disks to the back of the base plate. Anything less and the sled still tips forward. Now, I'm thinking that is a LOT of weight, but it's the only way that I can get the for/aft balace set properly. Side to side balance is set pretty well. Now, when I do the sled arc test to test the drop time, that's where the problem comes in. Since it is so bottom heavy, I'm getting a drop time of about 1 second or less. Of course the manual suggests to lessen the weight of the baseplate to get a slower drop time. However, I can't do this, because the only weight disks I have on the baseplate are in the back. I have none in the front because the monitor and battery in front are heavy enough. Since I can't remove weight in the front, I have to remove it in the back, but if I do this, then the sled will tip forward again, as there is not enough back weight to compensate for the monitor.

I guess I could add more weight plates to the top of the sled, but I'm not sure if that is recommended, as it would increase the recommended weight of the camera package. John, I think your tip on adding more weight though definitley helped get a better horizontal balance. Now it always returns to verticle no matter which way I tilt, which is nice. Now if only I could figure out how to get the drop time back all is good and I'm ready to vest up!

Edit...now that I think about it, it may help to move the monitor more towards the center post, since there are no counterweight disks in the front. I'll see if that works. At any rate, I'm excited to learn something new and this rig is much more complex than I thought, even after reading threads about it here. I think a lot of people assume with the Glidecam that you just take it out of the box, pop on the camera, and instant success. There's a lot to be done before you even use it.



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Old October 13th, 2003, 03:29 AM   #6
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Hi Brad,

What I would suggest rather than adding so much weight to the back is to move the camera at the top until it balances out, you've proved the weight you had previously on the sled was just about right because of your 3 second drop time, all you really needed was a slight extension of the post or another weight disk or two. A one second drop time is a bit too quick in my opinion, the key to all this is finding a balance between top heavy and bottom heavy and this normally lies somewhere in the 2-3 second drop time range. So I'd remove the weight you added adjust the camera position to balance it out and see if you can manage to get a drop time of about 2.5 secs, that should do the trick.


John.
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Old October 13th, 2003, 01:30 PM   #7
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Thanks John, that worked pretty well. I had to adjust the camera plate a little bit to extent it back more, so I could take some weight off the back of the base plate. Right now, I think it's pretty well balanced.

I finally discovered the Catch 22 to balancing this. The more weight you add to the bottom, the easier it is to get horizontal balace, however the drop time goes much faster. So to make the drop time slower, you have to decrease the bottom weight, which in turn makes the horizontal balance harder to adjust. My patience started to wear a bit thin last night as I couldn't find the perfect medium. Finally out of the blue after a tweak here and there it seemed to come into perfect balance with a drop time of a little over two seconds. I think I'm happy with that so I strapped on the vest and arm and went for a whirl last night. I think I did pretty well for a first run! I was able to keep it on for about 10 minutes before my back started to feel the pain (I'm sure I will last longer with more practice).

It's very cool how the camera just floats in the air. I think I am balancing it pretty well, though I am getting a bit of "wobble" sometimes when stopping or starting...ie the sled slightly drifts up and down. It's nothing major, just not perfectly still. I guess with practice I will be able to control this more. My girlfriend thinks I'm nuts as I scurry and bounce back and forth across the room. After I took it off I had this floating sensation in my body for a few hours. It's fun!

I'm going to practice a bit more and then hopefully post a video so you guys can check my technique and see if I'm doing it right. Thanks for the help John.
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Old October 13th, 2003, 02:13 PM   #8
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No problem Brad, glad I could help, I think all girlfriends must think we're mad, I roped mine into being in the video I first posted for advice, it took about 6 attempts for me to get one I was happy with, she wasn't amused :)

John.
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Old October 13th, 2003, 02:27 PM   #9
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yea I saw that video. Nice work!
Mine won't be amused either, but she is going to be the star.
(just doesn't know it yet). :)
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