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#1 Themis Gyparis

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Posted 20 September 2007 - 12:53 PM

What is the appropriate tension for an arm? I've heard different opinions, one of which claiming it should be bent downwards at about 30 degrees when post with camera is attached. Another opinion claims it should look upwards, but I've also heard this reduces inertia and causes less stability. Which of the above is right?

Thanks in advance
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#2 Jerry Holway

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Posted 20 September 2007 - 02:05 PM

What is the appropriate tension for an arm? I've heard different opinions, one of which claiming it should be bent downwards at about 30 degrees when post with camera is attached. Another opinion claims it should look upwards, but I've also heard this reduces inertia and causes less stability. Which of the above is right?

Thanks in advance

Themis-

None of the above is right.

Some arms prefer a slight upwards slant for nominal operating (G-series, Master Series, Flyer, Pilot, Merlin types). About 5 degrees.

Some arms prefer a slight downwards slant for nominal operating (I, II, III, IIIa and clones).

Not sure about the PRO arm.

The older arms are less forgiving if you are not at the nominal angle, i.e., performance will degrade a lot at one end of the arm's travel.

The G-arms are very forgiving of the position.

Older arms carrying less than the maximum weight are also less forgiving.

Nothing in the arm has anything to do with the inertial quality of the sled.

Jerry
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#3 Robert Starling SOC

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Posted 20 September 2007 - 02:32 PM

None of the above is right.

Some arms prefer a slight upwards slant for nominal operating (G-series, Master Series, Flyer, Pilot, Merlin types). About 5 degrees.

The G-arms are very forgiving of the position.


Hi Jerry, I think somehow I picked the same idea that each "bone" of the arm of my G50 should have a slight downward slant.... hmmmm? Of all people I should know this. Down to the workshop to unconfuse myself....

Thanks and all the best!
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#4 Themis Gyparis

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Posted 21 September 2007 - 03:26 AM

Well, my arm is Glidecam's Smooth Shooter arm and the post is the 4000 Pro. Also, my camcorder is the JVC GY-HD 100. Would you suggest maximum weight and arm tension? Anyone with experience on that setup? And, mainly, arm at a few degrees upwards or downwards? Any suggestion would be greatly appreciated.

Thanks a lot
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#5 Jerry Holway

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Posted 21 September 2007 - 08:44 AM

Well, my arm is Glidecam's Smooth Shooter arm and the post is the 4000 Pro. Also, my camcorder is the JVC GY-HD 100. Would you suggest maximum weight and arm tension? Anyone with experience on that setup? And, mainly, arm at a few degrees upwards or downwards? Any suggestion would be greatly appreciated.

Thanks a lot

The geometry of this arm suggests a 5 degree downwards nominal angle. Change it if your shot is generally near the top or bottom of the range (high mode/tall actor or really low mode,etc.) Overall performance will degrade but do what's right for the shot.

The arm will perform better with more weight; best at its maximum. But the performance increase may not be worth carrying the weight. It's a compromise and you must decide what's right for you and the shots you are making.

Adding weight to the sled will make it more inert, and you can add the weight intelligently to help you get more inertia, move the lens relative to the gimbal... but always it's about the shot and there is no single "perfect" solution for every situation.

Experiment!

Jerry
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#6 Themis Gyparis

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Posted 21 September 2007 - 09:18 AM

[/quote]
add the weight intelligently to help you get more inertia, move the lens relative to the gimbal...
[/quote]

Mmm... Interesting. Could you please be more specific about this? I am not sure I understand exactly what you mean. Sorry I'm a newbie :)Anyway, many thanks to everyone, you have been very helpful and I'm really glad about this! I'll try adding weight and see what happens, just as long as you can explain more accurately about the "intelligent weight adding"

Thanks a lot
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#7 Alejandro Wilkins

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Posted 14 March 2017 - 09:33 PM

...

The arm will perform better with more weight; best at its maximum. But the performance increase may not be worth carrying the weight. It's a compromise and you must decide what's right for you and the shots you are making.

Adding weight to the sled will make it more inert, and you can add the weight intelligently to help you get more inertia, move the lens relative to the gimbal... but always it's about the shot and there is no single "perfect" solution for every situation.

Experiment!

Jerry

 

does this principle: "The arm will perform better with more weight; best at its maximum"  apply also to a IIIa arm? I've noticed a difference in my shots from when I was flying an Alexa Classic with anamorphic glass as opposed to lighter builds, F55 and Mini's. I'm still fairly new to steadicam so at first I figured the performance was with me and not the rig, but I am now curious if there is an optimal weight for the IIIa arm? I have a gold spring recently serviced by Robert Luna, I believe he said the max load was 54lbs. 

 

I definitely put the rig down less on set with lighter builds, but ultimately I want to execute my shots with precision, so if I gotta weight it down, I will.


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#8 Jerry Holway

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Posted 15 March 2017 - 07:45 AM

Yes, it applies to all "3 spring" arms like the Model I II, III, IIIa, EFP and a host of others like the Luna arm.

 

Arms like the PRO or the Master Series or the G-series have a different arrangement of springs and attachments so that they are more iso and more consistent in their performance regardless of the weight the arm is carrying.

 

All these arms make, and have made, great shots...


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#9 Keith Wood

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Posted 16 March 2017 - 09:46 PM

Remember that the arm doesn't care WHERE the weight is, other than out at the end.  You don't have to put it on the sled, you can hang it on the arm bones or the post.  Depending on how much weight you need to add, you might even put a spare battery carrier there.


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