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.
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.
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.
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.
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.