GC2 vs GC2 test

[inorkuo]

I owned two gc2's for a few days and took the opportunity to hit some shots with both units reading the same shot at the same time. initially i had both units using the factory rev f flashes. the second day I installed a mega flash into one of them. some shots I did with the units side by side. other shots I did with them facing each other so one was in lefty mode and the other in righty. when the gc2's are side by side the ball detection areas overlap just slightly so that the gc2 towards the front has the ball in the very back of the window and the gc2 towards the back has the ball at the very front. there were a few interesting things that I noticed.

-the gc2 which had the ball in the back of the ball detection window showed more draw spin.
-when doing righty/lefty the gc2 in right handed mode showed more draw spin.
-with the mega flash installed putts with the mega flash unit show a little vertical launch while the rev f did not.
-one unit is reads slightly faster ball speed and lower launch than the other.

i suspect the small differences are caused by how the cameras are aligned causing very slight errors in the measured data points. both units were very close and in the end t

he big takeaway

is that the gc2 is an impressive launch monitor.

[Ironstrokes]

Thats interesting to read. Now I kinda want to see a video of someone doing that test now. Never really even thought about it before. Curious just how close they actually get across all types of shots. Nice post

[Js1010]

Yeah nice post - you excel file doesn’t download for me - getting invalid file specified. Might be a forum error. Anyone else able to see the file?

[grant2145]

Is this your video?? https://youtu.be/EFAWC45FX1U

[inorkuo]

Yea that's one of them. I did two videos while running both units. The rest of the shots were just photos of the LCD screens.

[Hemi]

Nice experiment, thanks for sharing

H

[Indodom]

Hmm, nice work, a vote of confidence for the megaflash also.

[LEO MODE]

Awesome test and very interesting finding. Foresight should definitely recognize you for this! When I have time again I will definitely try both GC2 and GC Quad by putting the ball towards the right edge of the hitting area (for the right handed) and compare the draw spin again vs Trackman 4. What this can potentially mean is that, in order to get the correct Spin Axis number and no draw-biased result on a GC2 or GC Quad (I also tested GC Quad vs Trackman 4 briefly at a golf shop unofficially for 2 hours but the data was no different than GC2+HMT unfortunately. I couldn’t see any tangible difference between the two), the ball should be placed on the right edge of the hitting area.

I also wonder if HMT data will slightly change as well, as the only noticeable HMT data difference vs Trackman was in the Club Path. Interestingly Club Path is measured on both GC and Trackman, and Face Angle is calculated by Trackman but Face Angle numbers were extremely similar. I know Club Speed measurement methodology is different between a camera and a radar, but why Club Path is being different is an interesting one.

I will definitely try both Spin Axis and Club Path again.

[codehead]

Yes. I am aware they are seperate. I just thought it was interesting the differences that I noticed. And yes the SE corner. This would be most similar to the setup of the "front" GC2 in inorkuo's setup in the video (side by side). Not an arrangement where they are on opposite sides (Lefty/Righty). Certainly East, I suppose how far South is indeterminate at this point from the video or his description. So yes I would say it contradicts his findings, but I suppose it requires much more testing. I am going to start keeping track of my sessions and change the location each time, then I will note average spin axis for all shots and maybe collect some long term data over multiple sessions. Also like I said. I can't separate the effect of raising it at this point either. Thanks for the work you have done already though. I just find it interesting.

[LEO MODE]

I also appreciate your findings. Very interesting indeed and after I receive my repaired GC2 again next week, I am bound to do more testing even with HMT.

[inorkuo]

from what i've heard, 3/4" higher than the hitting surface is ideal. i know that too high will give bad putting reads.

in the testing i did, i did get more draw spin with the ball placed on the east edge of the hitting window for a right hander. i did not try north vs south. it is very possible that one or both of the units could have been in need of calibration since they were both purchased use and that is why i got the results that i did. i've gone through 3 different gc2's now, and I compared the first to the second, and very briefly the second to the third. i didn't get to record any data when comparing #2 to #3 because i sold #2 almost immediately after getting #3. in the end the differences were minor and my takeaway is that the gc2 is a very solid launch monitor with good build consistency from one unit to the next.

[LEO MODE]

inorkuo By the way, would you think that the ball should then be placed on the left side of the hitting area for the left handers since they hit opposite of the right handers?

Also, I wouldn’t worry too much about the Ball Speed and Launch Angle, as long as they’re within a mile or a degree. That is within tolerance. Launch Direction can change significantly depending on how you aligned the unit though, so GC2 owners have to make sure to align it properly.

[inorkuo]

i'm not sure about that. i'm still wondering if the difference in spin based on ball placement is due to one of the units needing the cameras to be calibrated. someone with a consistent swing should try hitting several shots from the front, then the back and see if there is any noticeable difference in spin axis on their gc2.