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dynamically balancing my scout


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#1 Christopher Smith

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Posted 06 September 2012 - 08:10 AM

Hello,
I bought a steadicam scout at work for using with my JVC GY-790. I'm pretty decent with it and I have no problem statically balancing it. I feel that my shots could be way better and that the rig would be easier to control if I could dynamically balance it. I've spent hours trying to do so and made some improvement but think it could be way better. Does anyone have any advise for me on how to improve dynamic balance on the Scout? The only info I could find was to keep moving the battery and rebalancing. Not sure that has done much. Also not sure if I have the correct amount of weights on the bottom. I've taken some off and added some and don't see much of a difference. I have about a 3 second drop time for my static balance which is what the manual said was correct. Any tips are appreciated. -Chris
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#2 Alan Rencher

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Posted 06 September 2012 - 10:53 AM

If you haven't already, pick up the Steadicam Operator's Handbook. It goes in-depth about dynamic Balancing.

This quickest thing I can tell you to start with would be to put the camera's CG over the rear of the post, then adjust your counter balance (most likely your batteries) to give you a static balance. Spin the rig. If you haven't achieved dynamic balance, try moving your camera forward or back, and move your counterweight in the opposite to get back to dynamic balance. Is it better or worse? If it's better keep moving everything in the same direction. If it's worse, move them the opposite direction. Also, make sure that you've spread your side to side weight pretty evenly, and that you don't have any loose items that move on their own.

It's all in the handbook, and it's a lot more in depth.
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#3 Victor Lazaro

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Posted 06 September 2012 - 10:41 PM

If you haven't already, pick up the Steadicam Operator's Handbook. It goes in-depth about dynamic Balancing.

This quickest thing I can tell you to start with would be to put the camera's CG over the rear of the post, then adjust your counter balance (most likely your batteries) to give you a static balance. Spin the rig. If you haven't achieved dynamic balance, try moving your camera forward or back, and move your counterweight in the opposite to get back to dynamic balance. Is it better or worse? If it's better keep moving everything in the same direction. If it's worse, move them the opposite direction. Also, make sure that you've spread your side to side weight pretty evenly, and that you don't have any loose items that move on their own.

It's all in the handbook, and it's a lot more in depth.


If, like me, yo don't like to read, check out the EFP Video DVD. It's old (like old school) but it is an amazing source of informations.
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#4 Eric Fletcher S.O.C.

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Posted 07 September 2012 - 01:07 AM

If you haven't already, pick up the Steadicam Operator's Handbook. It goes in-depth about dynamic Balancing.

This quickest thing I can tell you to start with would be to put the camera's CG over the rear of the post, then adjust your counter balance (most likely your batteries) to give you a static balance. Spin the rig. If you haven't achieved dynamic balance, try moving your camera forward or back, and move your counterweight in the opposite to get back to dynamic balance. Is it better or worse? If it's better keep moving everything in the same direction. If it's worse, move them the opposite direction. Also, make sure that you've spread your side to side weight pretty evenly, and that you don't have any loose items that move on their own.

It's all in the handbook, and it's a lot more in depth.



And I and quite a few others will not only tell you but prove to you empirically that the book is wrong. Do a search on 90 degree test it will explain how to EASILY achieve dynamic balance
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#5 Wolfgang Troescher

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Posted 07 September 2012 - 05:09 AM

Hi Christopher,

don´t make the same error I made a few years ago when I learned balancing a steadicam: I thought it´s rocket science and I made my life more complicated than necessary. Dynamic balance is a realy easy thing! Heed Erics advice and you´ll be happy!

Wolfgang
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#6 Jerry Holway

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Posted 07 September 2012 - 08:38 AM

The book is not wrong.

I've proved this mathematically and in practice, in front of classes hundreds of times.

Pure crap, Eric.
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#7 Alex Kolb

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Posted 07 September 2012 - 05:13 PM

I won't say who's right or wrong, Jerry and Eric have way more experience than I do. What I will say is that I believe we all owe our livelihoods to Garrett Brown and his way of operating and teaching, which is what Jerry and the Tiffen classes continue to this day. So why is it that we now are turning on these techniques and teachings? You may disagree with them, but remember without them we wouldn't be employe, at least not in this profession.
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#8 Christopher Smith

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Posted 08 September 2012 - 04:57 PM

Thanks for all of the advice everyone. I'll spend some more time on it next week and will order the book as well. Thanks.
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#9 Twojay Dhillon

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Posted 08 September 2012 - 09:28 PM

[quote name='Alex Kolb' timestamp='1347056030' post='79775']
I won't jump into the pool of who's right or wrong (I am highly, highly unqualified to approach this level of decree), and Mr. Brown, Holway, and Fletcher possess infinitesimally more experience (exponentially so) in all areas of Operating than I do. What I will say is that I believe we all owe our livelihoods to Mr. Brown and his way of operating and teaching, which I believe is what Mr. Holway and the Tiffen classes continue to teach up until this day. So why is it that we now (in the recent past) have turned away, in methodology, from a few of these techniques and teachings? In a word: simplicity. In another (vis-a-vis "simplicity"): speed.

I'm not going to play either side of the line as far as classical versus modern operating/balancing styles, as that is a moot point. What I will say is that the book (quite some time ago) made me think that DB was some sort of Unobtanium Alloy, save for those of us with advanced degrees in Inter-Planetary-Exploration.

As soon as I read Mr. Fletcher's explanation (much, much time had passed since I had become frustrated with trying to achieve DB via the book's method) I walked over to my rig -- in my house -- and it worked. Within 7-10 minutes. It works today. It worked yesterday. It will always work because once you find the DB of your rig, the camera attached will never change the DB, so long as you do not change/keep the same the below-the-gimbal-masses-and geometry thereof. It will always work. Just as I am sure the book's method will work, albeit with the assistance of a calculator/abacus, I am assured that Mr. Fletcher's method works. Minus the computational accessories. And time.

I hate to quote infomercials (this may very well be the first time): SET IT AND FORGET IT. You do NOT NEED to move your monitor, save for low-mode.
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#10 Eric Fletcher S.O.C.

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Posted 08 September 2012 - 09:47 PM

As soon as I read Mr. Fletcher's explanation (much, much time had passed since I had become frustrated with trying to achieve DB via the book's method) I walked over to my rig -- in my house -- and it worked. Within 7-10 minutes. It works today. It worked yesterday. It will always work because once you find the DB of your rig, the camera attached will never change the DB, so long as you do not change/keep the same the below-the-gimbal-masses-and geometry thereof. It will always work. Just as I am sure the book's method will work, albeit with the assistance of a calculator/abacus, I am assured that Mr. Fletcher's method works. Minus the computational accessories. And time.



Not only that but my method will do something that Jerrys will NEVER do. It will DB a rig that can't do a full 360+ Degree spin.

If tools on set will get you fired (A concept that Jerry teaches...) then pulling out a tape measure, scale and laptop with a spreadsheet all to balance your rig (and to do it on every lens or accessory change) will surely get you banned from the industry for life
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#11 Alex Kolb

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Posted 08 September 2012 - 10:14 PM

I won't jump into the pool of who's right or wrong (I am highly, highly unqualified to approach this level of decree), and Mr. Brown, Holway, and Fletcher possess infinitesimally more experience (exponentially so) in all areas of Operating than I do. What I will say is that I believe we all owe our livelihoods to Mr. Brown and his way of operating and teaching, which I believe is what Mr. Holway and the Tiffen classes continue to teach up until this day. So why is it that we now (in the recent past) have turned away, in methodology, from a few of these techniques and teachings?



While I see the resemblence, that's not at all what I said. I DO consider myself to be qualified to state that the techniques most operators are taught, by Tiffen and Mr. Holway, Mr. Fawcett, etc, MUST be working, otherwise there wouldn't have been any new operators joining our profession in the past 10 years or so. I'm fine with people improving on these teachings, and even coming up with their own, but when sharing this all I would like to see is that we don't attack the people who got us to this point in the first place.

Tiffen and Tiffen workshop instructors tend to be the targets of a huge amount of negative comments, and I just don't think that's justified. I prefer some other companies to Tiffen, but I think if it wasn't for the original Steadicam (which many got into when it was CP, but the legacy lives on through Tiffen) and the Tiffen workshops, our industry would not be nearly as good as it is today. I'm not saying everyone has to love Tiffen, but I don't see why one side has to be wrong and the other right. There are more than two ways to skin a camera.
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#12 Jerry Holway

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Posted 09 September 2012 - 10:17 AM

Once again, Eric, you fail to say what is WRONG with the book, just that you have a different method that you prefer. A method, BTW, that does not contradict ANYTHING in the book.

Having another method does not make the book wrong, and I'm tired of your blustering nonsense.

I have several other methods or approaches to dynamic balancing, as well as ways to make quick dynamic balance adjustments if components or weights are added to or removed from the sled, regardless of where they are added or removed from. That these methods are not in the book does not make the book WRONG.

You have two methods described in other threads, ONE OF WHICH DOES NOT WORK if the monitor is raised up from the battery. We've demoed this in workshops, as well as the method you describe.

Your other method works reasonably well, but I've found it lacking in precision, and a final spin test often reveals a wobble. The test of a perfect spin test is the spin test, right?

I also find a resetting of the gimbal to get a proper drop time annoying, as I prefer a faster drop time than you method needs. This may or may not be an issue for you or some other operators.

Further, I like getting to know the feel of the rig while spin testing; I vary the configuration of my rig a lot (length and expansion) and used a lot of different cameras, so getting to know the rig while balancing seemed a plus. I could also get quite close to DB with a stand that wouldn't let me do a 360 spin - and if the rig behaved well (spun flat) within 270 degrees, let say, then it would behave while operating whip pans of 180 degrees.

To each his own on the METHOD one uses to get into dynamic balance.

The other absolutely ridiculous assertion you make is that one would get out a ruler or weigh components or bring out a spreadsheet ON SET. More frigging nonsense.

No one suggests that is done that way. Nobody measures anything on set or at the workshops I teach, but you could, in the privacy of your own home, try out a lot of configurations and see how it all works out, and measure and weight things if you like, or USE the spreadsheet to see what generally would happen IF you added a component, or say, switched from a TB6 to a Cinetronic monitor on your sled.

Clearly, it is good practice to design rigs so that they can be put into dynamic balance, and using the math and the spreadsheet is critical for that.

We've been using the math – first described by Arnold DiGulio in 1988 and shared with everyone via the Steadicam Letter – to design rigs from the JR, Merlin, and Smoothee to ALL the big rigs, Ultras, and ALL the rest. 1,000's of sleds.

We aren't remotely wrong about this.

You should go back and discover which of the methods you describe works, retract the other one, and stop being so smug and saying the book is wrong.

Jerry
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#13 Christopher Smith

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Posted 11 September 2012 - 08:54 AM

The book has been ordered. Thanks!
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#14 William Demeritt

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Posted 11 September 2012 - 10:07 AM

Look at Page 24 of the Scout manual, should be titled "Advanced Techniques - Dynamic Balance". They have a diagram middle of the page in a block describing what you're trying to achieve with dynamic balance. If you read through this section again, it will help you understand the fundamentals of dynamic balance. From here, you can decide which technique works for you.

I snipped the diagram in question, you should see it attached to this post.

Figure 1 (top most) illustrates Eric's philosophy, because with his XCS sled, he keeps the batteries, lower electronics housing and monitor coplanar. The CG of all 3 (the three "+" on the figure) are on the same plane, so the CG of the camera (the "+" inside the camera) goes right over the dead center of the post. His technique makes it so the CG's at the bottom are perfectly balanced, guaranteeing that any time you place ANY camera over the dead center of the post and fine tune the position, you achieve dynamic balance.

Figure 2 (middle figure) illustrates Jerry's philosophy (and I would dare say the overall Tiffen approach), because with the majority of the Tiffen sleds, the monitor sits higher than the batteries. With the monitor clamping options and the telescoping monitor arms, you can go anywhere from slightly above the batteries to HIGH above the batteries. You can see this indicated by the "+" of the monitor being higher than the "+" of the batteries and the "+" of the post base (lower electronics housing, lower section, whatever you have down there). Since the monitor CG will pretty much always be "above" the batteries, your camera CG will always sit a bit further back. Your Scout (and the Flyer) were probably the closest to having Monitor, Batteries and centerpost CG (negligible) on the same plane.

Figure 3 (bottom figure) is "absurd", as the diagram says, but proves the point: as the monitor rises up from the plane of the batteries CG and centerpost CG, the camera must move back. Camera moves further back, and the batteries must move towards the centerpost CG (or the monitor needs to go further out).

If I recall the technique for static balancing taught at the Lake Arrowhead workshop, after the sled is set to be bottom heavy (not insanely, but mostly) students are told to:

1. Place the monitor where you need it for the shot.
2. Find the camera's fore/aft CG (set the built camera on an iris rod, find the CG by balancing it until it's nearly balanced on the rod).
3. Place the camera on the camera stage with that CG right over the "back of the centerpost" (already setting the camera CG further back from the center of the centerpost for the reasons described above).
4. Move batteries in/out, depending on what you want for pan inertia.
5. Dial the camera position on the stage, either with rough adjust or fine adjust, to create static balance.

From there, you can adjust the drop time, revisit the static balance, and move on to dynamic balance (if you're into that sort of thing, you dirty man).

It's best to understand the fundamentals of the 4 weights on a pendulum/scale system and how they interact with each other. When you realize your sled is basically an intimidating, electronically wired version of that exact system, you'll understand what might be screwing up instead of reaching for a manual or textbook to look fo answers.

Some thoughts:

- Why do it Tiffen's way?: Because you have a Tiffen sled, and you can place your monitor in a variety of positions that might benefit you as an operator. Going full length on a 4-stage Ultra 2 to achieve super low mode, but staring WAAAAY up at your monitor that is coplanar to your batteries is a bad idea. You can bring the monitor down, closer to your eyes and that huge crack in the sidewalk you can't see when looking up. When the monitor leaves the plane of batteries and centerpost base CG, you'll have to use another technique for finding db. I'm inclined to think, though, that the 90 degree test would work on a Tiffen sled without a camera, but you'd have to place the batteries appropriately to counterbalance the monitor's 2 axis of placement (extension on monitor arms, position on centerpost) and not to set your pan inertia. Do that, and then place the camera's CG over the center of the centerpost, and I'd think you're in dynamic balance.

- Why do it Eric's way?: With Eric's method, or the "90 degree test", you set up your sled once and you're dynamically balanced for all cameras, all setups anywhere. Arri Alexa, Red Epic, Arri LT; all are dynamically balanced so long as you place the CG right over the centerpost like in figure 1 of the diagram. Of course, the drawback is that if you move your monitor, or aren't flying with the same batteries on your sled every day, then you have to do the 90 degree test every time there's a change. HD monitors that tilt at the yoke and not at the spuds that effectively run through the monitor CG will bone you every time you tilt the monitor. Keeping the monitor CG coplanar will confine your monitor placement options.

Hopefully some of this will be meaningful and helpful to you Chris. In the mean time: make love not war, and here's a funny photo:

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#15 RonBaldwin

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Posted 11 September 2012 - 02:27 PM

...burp
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