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GPI Pro Titan & Steadicam G70x

Rough Video Comparison

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#1 chris fawcett

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Posted 17 February 2017 - 10:47 AM

Colleagues,

 

I’ve been wanting to play with a GPI Pro Titan arm for ages, so a big thanks to Grant Culwell for lending me his. I can immediately see why people love this arm. It’s robust and beautifully made—though the G70x is lighter and has a couple of inches more boom range. The main differences seem to be that the Pro arm works right of of the box, whereas the G70x is tuneable for ride control. Here is a series of comparison tests of the two arms with the G70x arm tuned to 3/4 iso. I’m curious to know what you think.

 

All the best,

 

Chris

 


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#2 Kevin Andrews SOC

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Posted 17 February 2017 - 11:04 AM

The G70 handles those steps nicely! Good dampening and great body control by Mr. Chris.

 

I would add that most Titan arm owners run the arm a little de-tuned so the arm sections are just below level and you won't get that same kind of bounce as you would when it's wound up to level. 

 

Cool to see two Ferrari's of the industry in a race though! 


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#3 chris fawcett

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Posted 17 February 2017 - 11:07 AM

Kevin,

 

I'd love to redo these tests with the arm tuned as you suggest. I'll be in LA in April. Maybe we can work something out.

 

All the best,

 

Chris


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#4 Victor Lazaro

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Posted 17 February 2017 - 12:00 PM

Yesterday was my first day with my new Titan arm. I used to have the PRO Atlas one. 

My feeling is that the Titan is a bit less iso than the Atlas and yes, I also discovered that it would work better when detuned a bit. 


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#5 chris fawcett

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Posted 17 February 2017 - 12:48 PM

Let's do it!
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#6 Tom Rogers

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Posted 17 February 2017 - 01:25 PM

You have the PRO arm incorrectly setup. The arm section should both point slightly down. Right now you have the arm oversprung
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#7 chris fawcett

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Posted 17 February 2017 - 03:02 PM

Yes, like I said, let's redo the test. I'm all for it.
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#8 Alec Jarnagin SOC

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Posted 18 February 2017 - 01:41 PM

Fabulous stuff Chris!  Thanks for taking the time to do this.  And damn nice posture too (don't try that at home kids!).

 

 

As many, including me, have pointed out here and on Facebook, the PRO arm runs better with the bone angles slightly down from one another.  Then on the Facebook discussion, Ron Baldwin pointed out the possibility of testing different spring canisters in the PRO arm at various tensions to see if that makes a difference as well.  According to PRO (if I remember correctly), the arm behaves more or less the same regardless of spring configuration and settings, but I bet there is a slight difference in performance.  In other words, it would be interesting to run the test with the spring configured where the springs are cranked higher (i.e. four blue springs cranked up verses two black & two blue with less tension).  As Chris points out, the PRO arm is so good out of the box, but I wonder if like the G-70X, playing with tuning options changes the test results.

 

Obviously, both arms are amazing and I don't think this (or any) test is going to make one arm "king."  At the end of the day both arms have been used to make extraordinary shots.  The Operator brings the talent and picks their tools based on personal preference. 


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#9 chris fawcett

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Posted 19 February 2017 - 10:14 AM

Thanks Alec!

 

I look forward to re-doing the comparison with the detuned Titan, and 2 canisters, if possible.

 

See you at NAB?

 

Chris


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#10 William Demeritt

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Posted 19 February 2017 - 11:46 AM

In other words, it would be interesting to run the test with the spring configured where the springs are cranked higher (i.e. four blue springs cranked up verses two black & two blue with less tension). 

 

I would be curious about this outcome as well! When starting my day, I tend to evaluate my build as "heavy" or "light" for my 4 blue canisters. If heavy, I then crank my "more difficult to access" canisters to compressed (increase lift strength), and decompress them by 2-3 half turns (just so the compression bones aren't pressed against their maximum, just in case). I then pick up the rig and tune the "easy to access" canisters to the ride position that I like. Every 6 months, I swap the canister positions so they take turns in the difficult spots. However, I've been curious if having 1 canister in each section always "very compressed" or "backed off" had some impact. 


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#11 Alec Jarnagin SOC

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Posted 19 February 2017 - 02:03 PM

Chris, I'd still test with four springs in the arm as the vast majority of the time this is how we fly.  Many of us use two blue springs and two black springs as our default configuration, but as cameras have gotten lighter, those four springs have very few turns on them.  Thus, the same pay load could be flown with four blue springs cranked up higher so the question is, does this make a difference in performance?  I suspect if it does, its slight, but Ron Baldwin got me thinking about this when I was just in LA.  Again, according to PRO, it does not matter (if I remember correctly) but I'd love to see your test done both ways.


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#12 chris fawcett

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Posted 19 February 2017 - 02:50 PM

Alec,

 

If the payload allows, I'll do just that!

 

All the best,

 

Chris


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#13 William Demeritt

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Posted 19 February 2017 - 04:53 PM

I believe, in this post, Eric (kinda) explained how springs in series behave according to Hooke's Law. 

 

http://www.steadicam...showtopic=11978

 

Paraphrased from there: assuming no friction counteracting the pure math and physics, then 2 or 4 springs acting in series will always perform the same way, no matter if the spring canister with greater lift capacity is "turned" more or if the lighter spring is "turned" more. 


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#14 Marc_Abernathy

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Posted 26 February 2017 - 12:28 AM

Kevin,

 

I'd love to redo these tests with the arm tuned as you suggest. I'll be in LA in April. Maybe we can work something out.

 

All the best,

 

Chris

Id love to be a part of this, or at least buzz around as this "test/demo" happens.


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#15 chris fawcett

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Posted 26 February 2017 - 04:05 AM

Hi Marc,

We have no set plans as yet, though I'm thinking the Queen Mary workshop is as good a place and time as any.

All the best,

Chris
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