Trackman Face Calculation - Center Hit - No Gear Effect

[jake2]

Seems to me that the D-plane and the actual spin axis are seldom the same. Any comments?

Looks from that data that every 1 dimple off center makes roughly 2 degrees difference between D-plane and actual spin axes. So even half a dimple would make those numbers look a bit different. I'm guessing that some of the small variations come from measurement accuracy (0.1 degrees nothing).

Amazing how they come up with all those numbers. I wonder if D-plane bottom from club path and ball initial launch direction are enough to calculate the top that accurately?? It would seem to me that they almost have to be able to know and follow the sweetspot positions on those clubheads to be able to come to compute all that. Just guessing though...

Edit:
On second thought - if ball initial launch is considered to be on D-plane regardless of how centered the hit is, D-plane spin axes can be calculated from that and bottom of D-plane. Actual spin axes TM measures, so maybe that part is not so hard after all.
Maybe then it would be possible to figure out something about how far off center the hit just by comparing the two. Still I do not think it can be that simple. Whatever they do, they seem to do very well.

 

[TeeAce]

Maybe with the FS but the TM will give you no data at all as soon as there is not enough data to make a correct calculation!

That's what I'm saying. So why no path or ch speed given and AoA if they are measured from the club head?

 

[wulsy]

Sorry, but to me the difference in the D-plane and actual spin axis is absurd. Look at some of the centre hits. There's something else affecting the ball flight. Maybe there's a GE on every shot, or maybe it's something else.

I'm not knocking the usefulness of these devices in a teaching context, just seems to me that there's more to what the ball does than these devices can accurately measure.

 

[jake2]

Sorry, but to me the difference in the D-plane and actual spin axis is absurd. Look at some of the centre hits. There's something else affecting the ball flight. Maybe there's a GE on every shot, or maybe it's something else.

Look at the numbers!
Looks to me like up to 1 dimple off-center is still classified as center hit, but that's already roughly 2 degrees difference in spin axis. There are a couple of shots with just 0.1 dimple difference and then the diff in spin axis is very small.

If one dimple off is OK, then 2 degrees more/less spin axis tilt might not affect the ball flight that much.

 

[mjstrong]

Correct me if I'm wrong, but does this not mean that the D-plane and the actual ball flight are practically always TOTALLY DIFFERENT?

I definitely wouldn't say totally different. The D-Plane is the first part of the ball-flight-programming formula, with the effects of off-center contact (of which Gear Effect is the biggest) the remainder. The numbers provided by the LM's are still hugely useful as, without them, you can "know" very little information with just the naked eye.

 

[mjstrong]

2 degrees more/less tilt in spin axis may not change ball flight that much after all.

You're right, it doesn't.

 

[mjstrong]

Maybe there's a GE on every shot, or maybe it's something else.

Watch Tuxen's portion of ASII; hopefully it'll clear this up for you.

 

[cwdlaw223]

There is gear effect on every shot unless face and path are both zero. If the face is zero but the path is open or closed there will be gear effect.

 

[wulsy]

Look at the numbers!
Looks to me like up to 1 dimple off-center is still classified as center hit, but that's already roughly 2 degrees difference in spin axis. There are a couple of shots with just 0.1 dimple difference and then the diff in spin axis is very small.

If one dimple off is OK, then 2 degrees more/less spin axis tilt might not affect the ball flight that much.

Fair comment.

 

[Frans@France]

That's what I'm saying. So why no path or ch speed given and AoA if they are measured from the club head?

ch speed is almost always reported/measured. And you did not say that you said

pure zeroes to the face

 

[TeeAce]

ch speed is almost always reported/measured. And you did not say that you said

Zeroes = nothing

Sometimes we get some speeds yes, sometimes not even that, but face angle, path and AoA are missing always if you can't get the ball to the air well enough.

I think it's quite obvious it you think what the radar really can see

 

[Frans@France]

Zeroes = nothing

Sometimes we get some speeds yes, sometimes not even that, but face angle, path and AoA are missing always if you can't get the ball to the air well enough.

I think it's quite obvious it you think what the radar really can see

Sorry, I don't follow. Yes the radar looks from behind and as such can not see the face angle so it has to rely on calculations. What's your point?

If face angle/path etc are missing then the spin-axis is also missing. These values are strongly related and checks are built in to see if the values are reliable. If the values can not be deemed correct the TM will show --. Simple

PS : Vert. and Horz. swingplanes will sometimes still be reported when spin-axis and others are not.

 

[Frans@France]

So the radar look at the club from behind. This is wat a camera based systems sees.

I'll take the radar please....


PS Please note the reflection of the clubhead. These images come from a system that claims it can read face and AoA.....

 

[TeeAce]

Sorry, I don't follow. Yes the radar looks from behind and as such can not see the face angle so it has to rely on calculations. What's your point?

If face angle/path etc are missing then the spin-axis is also missing. These values are strongly related and checks are built in to see if the values are reliable. If the values can not be deemed correct the TM will show --. Simple

What about if the spin axis is measured from ball and face angle calculated to fit to that? When there is no ball decent ball flight, they can't get the numbers for club head.

My answers are based on question about possibility to get more results around impact area about the face and they explain why it's not possible and why also gear effect can't be seen. There is only one ball flight so there can be only one calculation for the club head.

I use my device a lot indoors and there we have to be really careful with that. Sometimes ball bounces back from the net to the right and the device gives really open face for that even player knows it's not. Same kind of effect than in simulators and big push draw where they read it sometimes push slice.

 

[TeeAce]

So the radar look at the club from behind. This is wat a camera based systems sees.

I'll take the radar please....


PS Please note the reflection of the clubhead. These images come from a system that claims it can read face and AoA.....

There is no meaning to compare to something even worse system, if any reason to compare for anything.

I don't really understand how people read my postings, or do they read at all There is no one message from me where I have said something about camera based systems or really anything against those radar systems. I just understand how they work and see that there is no always meaning to trust all the numbers, rather understand the flaws to be able to filter away something sometimes so we don't get mislead by that.

What I would trust best would be kind of IR sensor system with enough sensors and enough close to the impact to really measure the face, or maybe they could do it with radar looking from some angle to the face. Unfortunately those IR based systems seems to be more like toys for the moment and they can't be used to scientific purposes also. Anyway that could be the way to measure more things from club head like rate of closure, acceleration and deceleration profiles etc..

 

[Frans@France]

What I would trust best would be kind of IR sensor system with enough sensors and enough close to the impact to really measure the face, or maybe they could do it with radar looking from some angle to the face. Unfortunately those IR based systems seems to be more like toys for the moment and they can't be used to scientific purposes also. Anyway that could be the way to measure more things from club head like rate of closure, acceleration and deceleration profiles etc..

If you think you need that then buy the TM research model like the manufacturers did. You then get access to all data that the radar sees included those closure/acceleration etc profiles.. You do need to put around 100K on the table!

 

[Frans@France]

Sometimes ball bounces back from the net to the right and the device gives really open face for that even player knows it's not.

I really hope you checked the impact position on the face instead of using bounce on the backpanel which can only be correctly determined using highspeed video from the impact in the backpanel! If your image above is your backpanel then I'm sure you know that the backspin of the ball will "bite" that lose fabric and make any readings from the bounce ......well.........useless

I use the TM a lot indoor and did not saw any impact in the backpanel that even gave a hint that the TM was wrong. Only issue that I have once in a while is that the ball flight is completely off and then 1-3 shots later that ball will break.

Maybe those weird readings is the difference between the TM and your FS ? (tongue-in-cheeck)

 

[Frans@France]

....What I would trust best would be kind of IR sensor system with enough sensors and enough close to the impact to really measure the face,....

Get a golfachiever...infrared laser sensors.....

 

[TeeAce]

I really hope you checked the impact position on the face instead of using bounce on the backpanel which can only be correctly determined using highspeed video from the impact in the backpanel! If your image above is your backpanel then I'm sure you know that the backspin of the ball will "bite" that lose fabric and make any readings from the bounce ......well.........useless

I use the TM a lot indoor and did not saw any impact in the backpanel that even gave a hint that the TM was wrong. Only issue that I have once in a while is that the ball flight is completely off and then 1-3 shots later that ball will break.

Maybe those weird readings is the difference between the TM and your FS ? (tongue-in-cheeck)

I think you didn't get me right. The problem with short distance is that the radar is still seeing the ball and in flexible net it slides to the right. I think there is not that issue with long indoor use. But that just proofs how big influence to the result the ball move gives and it changes the club face direction to fit to the ball flight.

 

[Frans@France]

I think you didn't get me right. The problem with short distance is that the radar is still seeing the ball and in flexible net it slides to the right.

That would be a major error in the programming. A ball moving in the backpanel will show a drop in speed&spin. Any data after and including the time frame those drop are recorded should never be included in the calculations. I don't think that FS would have made such an basic error.