How to test your SkyTrak numbers against GC2 numbers for the exact same shot

[Mickey]

Some of you have seen the Par2Pro video wherein Cory compares carry, ball speed, spin and launch per ST against the same numbers from GC2 for the same shot. He has the two devices side-by-side. The issue - to keep the ST from blocking the cameras on the GC2, the ball must be placed well behind ST's red dot.

I went to GolfTown this weekend to test my ST distances (driver and 6 iron only) against the GC2 using the Par2Pro method. I could never get a single shot to register on both devices until a sales associate changed the configuration (see attached image). He moved the GC2 to a few paces off my left foot and changed it to read left-handed. You'll see in the image that the green light on the GC is on and the ball is on SkyTrak's red dot.

I then hit about 30 drivers and 40 or so 6 irons. Every single shot registered on both devices perfectly. I was only interested in carry, spin, launch and ball speed. I'm pleased to report that after hitting 70 shots, a grand total of one had SkyTrak come in more than 5 yards short of GC2. In fact in virtually all cases ST distances were within +/- 5 yards of GC2 with no bias either way. This was true for driver and 6 iron. What's more, the launch, spin and ball speed were also crazy close to each other.

Bottom line: ST is not "a good launch monitor for the money" - its a "good launch monitor" - full stop.

It would take a special type of incompetence to screw this up, but it appears that SkyGolf is making a go at it.

[Stiggity]

davray666 if you still have your skytrak, could you test this out? Always liked your input in these topics

[Stiggity]

THanks for your input! davray666. I do have a follow up. How does cold affect the accelerometer. I play in a cold garage in the winter and am debating warming it up before hitting. I have been playing with balls stored inside my house to prevent cracking and the unit stays in the house until i go out in garage. Thanks

[davray666]

Just to clarify. We are talking GC2 not ST.
I only have a few data points on the temperature thing so it's a guess more than a scientific fact. My garage is heated but we had -15deg C a few weeks ago and now have +4. So the garage temperature has been fluctuating some 7-9 degrees C. Lowest 11 deg C and highest 18 deg C.
What makes this strange is that once the GC2 has been on for a while it generates it's own heat and should therefore stabilize. But it does not. The bias tends to stay for the whole session. Need more experiments to say something for sure but I am busy playing PG tournaments so not a lot of time for testing and experiments. My GC2 is placed on a leveled platform that is bolted down to the concrete floor and has a protection around it. So it will not move even if a ball hits the protection since the protection is also attached to the platform and have no contact with the GC2.
That is how I know that it does not move between the sessions and why I don't have to re-align it every time.

During a game there is a lot of putting and chipping. So if the putts are straight. (I have an alignment line on the leveled stimp 10 putting surface So I can see if the put was straight or not) and the 40+ deg chips have a 2 deg bias to the right. Then you know it's the accelerometer tilt value that is off vs. gravity.
Theoretically this should apply to the ST as well. But since the HLA is all over the place for high launching shots, it's difficult to determine a bias. Now that we will get a feature that allows you to see the unit tilt and role. ( and maybe even calibrate the accelerometer????) Things might get better. But I have not tested that yet and probably never will.

[jrz]

Stiggity, while I can't provide detailed temperature measurements I can say that I have been hitting my ST in a large, three car detached garage with no insulation here in Denver. It is an icebox. I installed a small 30A electric heater that blows towards my hitting area and I am seriously doubtful that it is warming the air enough to impact ball flight. I store my balls in one of those Callaway Pro Caddie Ball Shaggers in the garage. I have not seen any decrease/change in distance or shot shape.

[Gamble Gamble]

Very interesting. Thanks for sharing. My biggest concern with ST was the driver distances.

[Wyzyguy]

DavRay666.. What are the issues with the wedge shots? Reading them? Spin Rates? Please clarify. I am a SkyTrak owner and have had no issues in the wedge department. Thanks in advance.

[davray666]

Hi there Wyzyguy. Your statement is interesting because it might be that you have a unit that can do stuff that mine and others can't.
Please let us know if that is the case?
Problems are as follows.
1. Flop/chip shots regardless of ball placement vs. laser dot will not register. That is if they are 40+ VLA and stuck like you intended to carry some 30 yards or longer. In those cases ST picks up something that it claims is 45 degrees it's more like 35 in reality. For full swing shots for max carry distance I can use my 44 deg loft PW and no other club that has a higher loft. It can pick up the 48 deg wedge randomly but when it does the VLA & HLA is way off.

2. Horizontal launch angle is way off for shots that launch high. E.g. progressively worse as the VLA increases and speed decreases. As an example, 40MPH ball speed, 35 deg VLA, 5000 spin chip shot. HLA will often be +/- 6 deg wrong and at times way worse than that.

[davray666]

Compared to my shots your vertical launch angle is much lower than mine when I use a 60deg wedge. Does not mean I am right and you are wrong. Just 2 different swings producing different shots. My 60deg wedge is typically above 40deg VLA for a full swing and above 50 when I do bunker style flop shots. Especially shot number 8 makes no sense if I compare it with my typical data. That would indicate that you are launching your 56deg somewhere around 30deg. If that is the case then I understand why you have no issues with wedges.

[Wyzyguy]

Hello DavRay666. I hit some flops and got readings in the 51* range pretty consistently with zero no reads. I must agree...we deliver the club differently. What jumps out to you about Shot #8 vs say Shot #7? Curious. A 30* 56* for me would be a little high. LOL...

[davray666]

What jumps out is that it's very different from mine. Not implying anything. I would not be surprised if your HCP is lower than mine.
I tend to have higher launch and shorter distance for all my wedges than what would be considered normal among skilled golfers.
I have done a lot of testing and measurements with ST and I have also managed to get it to register 52deg VLA shots. Problem is that they where nowhere near 52 deg. Anyway if your happy and it does what you need it to do. Congratulations! There is no other tool that you could have bought for that money that would deliver the same experience.

[coz]

Calculations may do something different for a hook/draw vs a slice/fade. So if you are hitting draws as a righty and the unit is backwards reading as a lefty, it is thinking it is a fade and so the algorithm may come up with less total yardage than if it were on the other side.

so what your saying is the total distance and carry may vary due to the algorithm? But the direct measurements should be identical right? Spin, ball speed, launch etc...

Sent from my SCH-I545 using Tapatalk

[Godfather]

Speculation. I don't know the extent of the spin data the units are able to detect. We all know the carry and roll distances are calculated, but not exactly how.

[coz]

Hi there Wyzyguy. Your statement is interesting because it might be that you have a unit that can do stuff that mine and others can't.
Please let us know if that is the case?
Problems are as follows.
1. Flop/chip shots regardless of ball placement vs. laser dot will not register. That is if they are 40+ VLA and stuck like you intended to carry some 30 yards or longer. In those cases ST picks up something that it claims is 45 degrees it's more like 35 in reality. For full swing shots for max carry distance I can use my 44 deg loft PW and no other club that has a higher loft. It can pick up the 48 deg wedge randomly but when it does the VLA & HLA is way off.

2. Horizontal launch angle is way off for shots that launch high. E.g. progressively worse as the VLA increases and speed decreases. As an example, 40MPH ball speed, 35 deg VLA, 5000 spin chip shot. HLA will often be +/- 6 deg wrong and at times way worse than that.

? I use my 58* and work it on all yardages up to its max without any problems? I work with all my wedges 70% of the time. My only wedge problem is wgt soft chips. ????

Sent from my SCH-I545 using Tapatalk

[#gcw]

Great stuff Mario, excited to get my Skytrak in a couple of months now makes it much easier to chose between the skytrak and the much pricier GC2.

I can handle a delay and a few ropey flop shots which is a shot I would rarely use anyway unless really needed (short sided etcc)

The data by all accounts looks extremely close

[Timdm3]

I use my 60* all the time with no problems. Full or half shots. Usually place a couple inches in front of laser. My hitting distance is close to screen (around 6') and ball is almost hitting ceiling with 10k+ spin.

[davray666]

That is impressive indeed. None of the early ST units with the original firmware could pick up those shots. I am not talking about an occasional miss.
I mean 100% failure. So this should reasonably mean that the latest app along with the most recent firmware solved that problem.
Mine has been collecting dust since I bought the GC2 more than 4 months ago. Guess I need to update the firmware and test it again.

[hks8888]

"None of the early ST units with the original firmware could pick up those shots."

In my case, (I was an early adopter), I was able to hit flop shots from Day 1 or 2 after I was advised to put a ball an inch in front of the red dot. The highest VLA captured was probably 41 degrees.

[wee988]

I wish you would try the new updates and get back davray. I recently tried flops in wgt and on the range app. Picked up about one in ten at best. I sat on the range app hitting fairly normal pitches (short meaning 10ft in the air) and it took about 15 before I got one to pickup). Frustrating as I don't know how the sim playing will work. Wgt is pretty unplayable for carious reasons (viewing angles etc) but the inability to consistently pick up shorter shots around the green is clearly the biggest obstacle. I have read all forums and tried different ball positions around the laser and lighting with no noticeable improvement.

Love the thing as a launch monitor and for practice but hope some improvements can be made for pitches and chips so sim play can happen....if it ever gets released

[dsailer]

so I assume you have the latest firmware? Meaning this issue could be tied to the units. I need to go back and do more testing. I didn't know firmware update addressed this. I sort of gave up trying to hit 60 degree wedges. My PW is 47 and I don't get a lot of shaft lean but I'm picking up that PW pretty consistently. Can't recall my launch angles with the club off the top of my head.

[wee988]

I too will recheck the firmware. I am pretty sure it is up to date

[apljb]

Apologies for being a bit late to this particular party, but I found davray666 comment/question interesting.
I have a fairly early unit, bought Jan last year, I've never had an issue reading full shots with 60* wedge, even from the outset with the original firmware, and my numbers closely correlate with real world distances and TM data.
I can't say I've paid particular attention to full on flop shots, but they do register for me routinely.
FWIW, I place wedge shots, hybrids and woods on the red dot - my irons behind, because my white graphite shafts don't register at all unless I do...

[TorchRedRob]

Sounds like it's a launch angle thing. I have no troubles up to a 60deg wedge, but I launch it low to mid 30's VLA on full shots. I haven't even tried flop shots off the mat, because it scares the heck out of me...
Chips have been really good for me once I figured out where to place the ball with my particular unit (YMMV)

[davray666]

Alright so based on all the feedback so far the conclusion is that I have a unique swing and launch my full and 3/4 swing wedges way much higher than everybody else.
Just came back from a tournament round and looked a bit more closely. I actually launch the full swing 60deg closer to 50 than 40 deg and it carries some 60yds with around 11k spin.
A semi soft typical bunker shot with face open, launches above 50 deg.
With that said if i have to or want to for whatever reason i obviously can launch it lower. But the stock swing is what it is.

[TorchRedRob]

just curious, but what is the swingweight or MOI of your wedges relative to the rest of your irons?

[davray666]

All wedges are Clevland 588 RTX with stock shaft. I carry 60,56,52 & 48.
The irons are Callaway X2hot with stiff shafts, so much heavier.

[TorchRedRob]

Just wondering because I have found that heavier clubs launch lower for me / more lag. I was thinking maybe you had some odd combo of really light wedges. Either way- doesn't really matter. Not a lot of launch data on wedges is out there. I guess because as long as you can score with them, it doesn't matter

[Scyukon]

So I met up with Cory (Par2pro) tonight at DeBoers golf in Edmonton. They generously allowed us to use their simulator at same time as the Skytrak.

Big difference for me - was hitting my 7 iron 170 like I do outdoors and my driver 250+ just like outdoors. And it was showing up consistently on both units.

So this leads us to speculate (and for me to keep testing in my basement!):

Perhaps a lighting adjustment is in order. The simulator there had a light shining down directly on the ball. In my setup the lights are to the right of me on the ceiling when swinging.

Perhaps mentally I am more claustrophobic in my basement than in a wide open room with 15 foot ceilings. I feel like I am busting a nut trying to get distance though, but will keep on experiment with how the light shines on my ball.

Either way I am happy to report that my unit works properly. Thanks again to Cory for hooking me up at DeBeors, and patiently running tests with me - that is top notch customer service!

And also thanks to Jaret at DeBoers, who also provided us with some much longer drives than mine to show the unit would register those as well.