SkyTrak - Side Spin

[jaskoh1717]

Does anyone have issues with the side spin readings with your SkyTrak? When I use Skytrak, it says I have a massive draw/hook and when I go to the course, I play a baby draw at the most (mostly straight). I was just curious if there is something wrong with my setup. I am using the same ball and I have the case with the level so I presume everything is setup correctly. I am developing some pretty bad habits and I am always missing greens and sometimes fairways to the right because I think the ball is going to come back.

Has anyone encountered this? If so, are there any suggestions on how I can change my setup to help match my actual ball flight on the course?

[Bubba22]

If you are offset then you need to appreciate it. TGC will allow for offset compensation so you can hit straight to the right or left side of the screen. I don't think the Skytrak app allows for this. If so then aiming from offset to center of the screen will cause you to slice or hook.

[DirtyGarry24]

Can you elaborate on this? I am a pretty solid 4 - 6 handicap. I work regularly on my Skytrak range app. I then take my swing to the TGC game and am baffled at some of the flight patterns that I produce at times.

Furthermore baffled at the flight characteristics that TGC shows relative to where my ball ends up. Sometimes zeroed out can produce 40 yards offline to the left. How?

For instance, I know fairly well what a zeroed out face to path should feel like. I've proved this time after time in the Skytrak range app. However, I can produce some wild hooks off the tee "in game" that are "wtf" moments.

To compensate, I can produce that massive block that honestly is more realistic.

I say all of that to say this, both shots can register a decent path to face ratio. 0 - 3 in both directions.

Please explain...

[golfnut1]

would anyone know if the software key is required to run the VFIT module of the VSeries software for the Accusport X VX-100?
if so, a source for the software key?
Thanks in advance

[Bubba22]

would anyone know if the software key is required to run the VFIT module of the VSeries software for the Accusport X VX-100?
if so, a source for the software key?
Thanks in advance

Are you perhaps in the wrong thread?

[ironFrank]

Does anyone have issues with the side spin readings with your SkyTrak? When I use Skytrak, it says I have a massive draw/hook and when I go to the course, I play a baby draw at the most (mostly straight). I was just curious if there is something wrong with my setup. I am using the same ball and I have the case with the level so I presume everything is setup correctly. I am developing some pretty bad habits and I am always missing greens and sometimes fairways to the right because I think the ball is going to come back.

Has anyone encountered this? If so, are there any suggestions on how I can change my setup to help match my actual ball flight on the course?

I have had the same and tested it as well. Finally I talked to support and sended it back for check up. I was as well slicing like hell but the ball was flying in a draw like it should. I've tried out all the setup tips here in the board and pointing the ball wit the logo to the skytrak but nothing helped. 5 out of 10 shots where completely wrong. I will update you when I have my ST back.

[James James]

Did they find anything wrong with it?

[ironFrank]

"@James James"
I got it back with "all was ok" and "we didnt fix anything" but it worked after that. Strange though

[James James]

Perhaps it just needed a holiday!

[docsmilez]

The more and more threads I read, the more I'm thinking this is a TGC issue. Users of both GC2 and skytrak seem to have hook side spin issue in TGC but not on any range or other software or in real life for that matter.
with the gc2 I can see my readouts. In TGC a 1000 side spin with 1-2 degree right will hook from right of green to left and off of the green. On the range In FR1 software those same numbers produce a nice realistic draw (actually starts right and ends maybe 5-10 feet left of target line).

I have read about 10 separate threads on people with this issue and none seem to have figured it out.

my only solution was to decrease side spin values in gsx to make it more realistic. But that won't be allowed in tournament play.

[ironFrank]

The more and more threads I read, the more I'm thinking this is a TGC issue. Users of both GC2 and skytrak seem to have hook side spin issue in TGC but not on any range or other software or in real life for that matter.
with the gc2 I can see my readouts. In TGC a 1000 side spin with 1-2 degree right will hook from right of green to left and off of the green. On the range In FR1 software those same numbers produce a nice realistic draw (actually starts right and ends maybe 5-10 feet left of target line).

I have read about 10 separate threads on people with this issue and none seem to have figured it out.

my only solution was to decrease side spin values in gsx to make it more realistic. But that won't be allowed in tournament play.

No, not really. The Side Spin is not really the matter as far I am experiencing more and more situations.

I have the feel that at the end of the trajectory, the influence of gravity is too low. When I hit a hard slice the trajectory is up to the end in a more sideways flight but at the end of every trajectory, gravity has more influence and the ball comes down hard vertical. It will not move to the right on and on and on. But exactly that is, what happening.

I saw shot tracer shots on Honda Classic that weekend and that was more like it should be. Fades and draws are coming vertical down at the end and not sideways.

[goatbarn]

That's exactly a side spin issue. It's called spin decay. It's been brought up about TGC before, and I believe we could use more of it. Not sure how easily this could be calculated mathmatically, but maybe in the ball flight algorithm there is a setting for this. I have no idea. That's an @ProTee question.

Total spin of the ball decays over the "life" of the ballflight due to air resistance and rotational inertia. Due to this, the ball curvature dies off more rapidly during the decent and you should see it fall more straight down vs continuing to curve. Depending on amount of spin axis, it may still curve, but it should always curve less as it descends.

[docsmilez]

I agree that we could use more spin decay after seeing those shot tracers at the honda classic. Or really any other means of decreasing spin effect on the ball. As of now it would be nice if we could allow a 10% decrease in spin settings on the tour. I hope that some of these issues are addressed in the coming updates to TGC.

[James James]

I tested mine against a Trackman today and the results were uncannily accurate except spin axis. The spin axis was significantly higher leading to significant curvature of the ball. I got a colleague who hits the ball with the opposite shape to me and he replicated the result. We were seeing the ball fly straight with minimal curvature. Trackman measured a very small spin axis and captured 20ft offline. Skytrak was showing a significant spin axis tilt and 20 yards offline.

I also hit some drives within 10 yards of the target line and ST showed a 60 yard hook.

What seems weird is the consistency, it didnt get the shape or spin axis wrong and the rest of the data was near identical (it surprised me), it just got the magnitude way off.

I am waiting for my Trackman data to be sent to me so I can study it in more detail.

I believe Trackman in outdoor mode calculates spin axis based on the observed flight, so I would expect some differences, just not of this magnitude.

Support have advised me to reinstall the app, not sure how that will help but heres hoping...

The comments of goatbarn also resonate. If there was no spin decay it would exaggerate everything.

[erikh5014]

James were you outside when you tested against trackman. I wonder if GC2 would also have the same issue since its also not seeing the entire ball flight.

[James James]

Yes outside and I was thinking exactly the same thing. Trackman derives spin axis from the first 30 yards of flight so it has much more time to calculate it. Trackman has a locator on their website, but I dont think foresight have the same and I am not aware of any in Scotland that I could go and test against.

[ironFrank]

I tested mine against a Trackman today and the results were uncannily accurate except spin axis. The spin axis was significantly higher leading to significant curvature of the ball. I got a colleague who hits the ball with the opposite shape to me and he replicated the result. We were seeing the ball fly straight with minimal curvature. Trackman measured a very small spin axis and captured 20ft offline. Skytrak was showing a significant spin axis tilt and 20 yards offline.

I also hit some drives within 10 yards of the target line and ST showed a 60 yard hook.

What seems weird is the consistency, it didnt get the shape or spin axis wrong and the rest of the data was near identical (it surprised me), it just got the magnitude way off.

I am waiting for my Trackman data to be sent to me so I can study it in more detail.

I believe Trackman in outdoor mode calculates spin axis based on the observed flight, so I would expect some differences, just not of this magnitude.

Support have advised me to reinstall the app, not sure how that will help but heres hoping...

The comments of goatbarn also resonate. If there was no spin decay it would exaggerate everything.

SkyTrak_Seth

Seth, do you have any idea about that? We are all observing the same issue where the sidespin takes a too high influence on the ball flight. That can cause, that we try to correct our swing even if there is not really something to correct. I had the feeling already since November , but now, where more people see the same it is no longer a feeling.

Would be nice if you pick that up for your development Team.

Cheers
Frank

[keither5150]

Goatbarn has a great point about spin decay. On TV when you see the pros hit. The trackman has the ball curving, and then once it starts it's decent, the ball almost falls down in a straight line. IRL, we have a really hard time seeing this as it's so far away. I can see it on a big draw with my 8 iron to a lessor extent. It would be great if TGC could calculate that with more accuracy.

[James James]

I now have my trackman data and I will attempt to produce a detailed analysis in a new thread. However, it is already obvious my Skytrak is very accurate on everything except spin axis which is consistently way off.
With my driver over 35 shots it was on average 11deg different from Trackman (ST = 11.1Deg, TM=0.02Deg).
My playing partner hit 8 drives with an average difference of 9.6deg (ST=-6.9deg, TM=2.5Deg)


I have also reinstalled the app, not that I have much confidence that could fix the issue?

[BadEddieKit]

So If I understand correctly, a straight shot will be a straight shot on a skytrak. But a hook or slice will be exaggerated?

[James James]

In general yes, but not always!

[James James]

I have now documented part 1:

http://golfsimulatorforum.com/forum/skytrak/108596-skytrak-vs-trackman

[SkyTrak_Seth]

First, this is not a reinstall the app issue

James, thanks for doing all the testing. Looking at it, it looks as though the core data is different, not our flight model. The biggest factor here to consider with Trackman is wind. Are you using any correction/normalization? Whenever we do our robot testing, it's done early in the morning at Golf Laboratories when there is zero wind. Another thing to make sure of is that each time you place the ball down, especially for this type of super-detailed testing, make sure a mark/logo is facing toward the unit to minimize the chance of a mismark.

[James James]

Reinstalling the app did seem like weird advice!

The data should be correct in the sense I exported all of the shot data from skytrak and did the same from Trackman. I kept note of the 3 missed shots (1xTM, 2xST) to keep the data aligned. The only calculations I performed were converting between total, back, side and spin axis (can we get in-app conversion and export of this ).

At this stage I didnt use any normalisation because it could skew ball speed and spin measurement data which would be unfair on ST.

It is pretty clear to me (and it shouldnt be a surprise to anyone) that the measured data and flight model used by ST is accurate. The only parameter I cannot reconcile is Spin Axis and it appears to larger on ST (in the correct direction) frequently. My understanding is that Spin axis is not affected by wind (http://blog.trackmangolf.com/spin-axis/), so this seems strange?

If total spin was off I would assume it was an issue with the images captured and passed to the app. However, total spin is unerringly accurate which suggests the spin axis component is being misinterpreted by the software?

[GungHoGolf]

JJ as I mentioned in the other thread, you might test with the ST unit leaning significantly towards the ball, and away from the ball, and see if it's possible to align the unit with the expected spin axis readings. Probably best to use driver for such a test, because a high launch angle would show significant HLA offset with the unit leaned towards or away.

[goatbarn]

My understanding is that normalization does not change any data measured. Just eliminates wind and will change altitude, temp, and humidity to a default that would better match skytraks. Ball conversion would change data measured, so maybe you're thinking of that.

[James James]

GungHoGolf I attempted to test this earlier. It felt like tilting the unit positively (towards the player) moved the spin axis left (for me) but I don't think a human (certainly not me) is reliable enough to statistically prove it. I will however retest this when I next goto the range and am able to see complete ball flight.

N.B. A 3deg tilt is huge, and moves the levelling bubble off the edge. Tilting the unit 3 degrees inwards also lead to some missed shots, presumably the second shot was out of frame?

[jut111]

Interesting. And then there is the question of which tilt/roll to go by, the bubble level or the software which doesn't always line up..

Frankly I'd kind of like it to be over reporting spin axis. I want my practice to be hard and punishing.