GCQuad Clubface Data

[stunted]

I just purchased a GCQuad, and I was disappointed by the face data. It seemed to vary a ton, and sometimes it was really far off the starting angle. There's no way the numbers could be trusted. In some lessons I've had with a quad it seemed off as well, chalked it up to bad strikes. But after getting my own quad and having to hit almost golf balls (apartment setup), still bad. The balls weigh a lot lighter, so it's not going to twist the head as much. Not sure if it could be the club or sticker placement. But watching on YouTube it seems like it's common to see misreadings as well.



I was pretty annoyed after all that money spent, but knowing that face determines starting angle, maybe there's some hope. Especially since path and starting angle do seem like accurate readings. Path has really small standard of deviation, and starting angle passes the eye test of where the ball hits my net. Doing some digging I found that you can plug those into an equation and figure out clubface:
https://www.researchgate.net/publica...of_a_Golf_Ball

Assuming slope is 0.7, in other words 70% of starting line, the new face to path comes out to:
(Side Angle - Club Path) / 0.7

And face to target comes out to
Club Path + (Side Angle - Club Path) / 0.7

Here's an example of a bad reading I had:
Path = -.8
Face to Path = 6.3
Face to Target = 5.5
Side Angle = .9

If the face to path was 6.3 degrees, there's just no way it pushed the ball only 1.7 degrees. After the equation:
Face to Path = 2.4
Face to Target = 1.6

What do you guys think? It does seem a lot more logical. Maybe it's not perfect but it should be accurate enough for feedback. If it all checks out, I'll make a chart so that it's easy to check on the fly.

[stunted]

I also wonder if ball placement makes a difference. Has Foresight said anything about this? I could test it out, compare how close it is to the equation's results.

[Andy_Golfer]

With FTT = 5.5 and Club Path -0.8, the H-Launch angle of 1.7 doesn't seem right under the normal condition. Check out www.vuegolf.org for FlightScope numbers. 132 shots captured from LW to Driver. On Graph page > Select X = ftt and Select Y = h-launch, it shows relatively linear relationship across all clubs. You can merge SampleData_1 and SampleData_2 on the Merge page. To check the actual FTT, Club Path and H-Launch numbers, Dashboard page > Session Averages > Select Data Category = D Plane Data. Also Session Details > Select Data Category = D Plane Data. You can sort the data by any of the data parameters or search it.

[Wormburner]

The way way foresight reads the Azimuth or side angle is the initial horizontal angle relative to the target line. The azimuth or side angle, combined with side spin, will determine the final ball position relative to the target line. So the side angle is read right at impact. How far was ball off target line down range on that particular shot. What were side spin numbers? The slightly negative swing path with a pretty open face will cause a nasty slice for sure but I don't believe the initial horizontal launch will be as far right as you think. I use a few launch monitors (GC quad being one of them) and they all read the side angle very close to each other.
Out of curiosity, what did you think the side angle should be?

[Afor1991]

Sorry to tangent… but do you have any opinion on the flightscope x3 indoors?

[Wormburner]

That is a unit that I have not been able to see in action but I read good things on it. I still prefer the hi speed camera and IR technology over doppler indoors due to not needing a lot of space to read ball and club data.

[stunted]

With FTT = 5.5 and Club Path -0.8, the H-Launch angle of 1.7 doesn't seem right under the normal condition. Check out www.vuegolf.org for FlightScope numbers.

Interesting that it shows the slope as 1, implying face is all that matters. Anything from .7-1 does sound a lot more reasonable than the quad’s readings. Do you think after the equation that FTP and FTT at 2.4 and 1.6 sound right?

Out of curiosity, what did you think the side angle should be?

Ya did think that the side angle would be initial. I think the ball data should be really accurate so not worried about that, and your test confirms that too.

In my example my quad read a slightly out to in path, with the ball initially going slightly right of target. But then it read my face as very open, which seems wrong - I expect it to be open but not anywhere near that much. Also I think side angle is accurate so it’s used as a constant. Could be hard to picture because we’re using numbers instead of images or I’m just not clear.

Bad Reading
Path = -.8 L
Face to Path = 6.3 R
Face to Target = 5.5 R
Side Angle = .9 R

After the equation:
Path = -.8 L (constant)
Face to Path = 2.4 R
Face to Target = 1.6 R
Side Angle = .9 R (constant)

[Andy_Golfer]

FTT 1.6 for Side Angle = 0.9 and Path = -0.8 for a mid-iron swing sound about right. Could you get your GCQuad re-calibrated by FS? Is there a way to verify with FS to see if your GCQuad is producing correct numbers?

[stunted]

Didn't consider that or even know they could recalibrate, I'll give that a try.

[Morini]

The formula assumes centre face strike. Otherwise the gear effect will affect spin axis etc.

[stunted]

True. Could figure out how to account for that later.

Made a chart:

[Andy_Golfer]

I have captured 149 shots from 2 sessions (1 Outdoor & 1 Short Indoor) using a FlightScope Xi Tour. Based on Club Path + (Side Angle - Club Path) / 0.7, the largest variation between calculated FTT and FlightScope FTT was 1º. H-Slope of 0.6 for wedges, 0.7 for irons and hybrids and 0.8 for woods applied. Shots were removed if club data was not captured by FS. The outdoor session was conducted on an outdoor driving range and all types of good and not so good shots were captured. The short indoor session was on a mat and 3m long-hitting bay and also all types of shots were captured. I have included a FS_Club_Face_Data.xls file to look at. It is a relational model so you can sort and filter the data using columns. So your example of FTT = 5.5 seems excessive. How many shots were like that? Are you able to export a session data from GCQuad as a CSV file to look at?

[Andy_Golfer]

Leo mentioned his GC2 & HMT were calibrated with ForesightSports 3 times and hence they are within tolerance and very consistent. https://golfsimulatorforum.com/forum...hmt-with-bonus

[wbond]

Weird thing, why would a device need to be calibrated 3x? Is the calibration that process that poor?

Leo mentioned his GC2 & HMT were calibrated with ForesightSports 3 times and hence they are within tolerance and very consistent. https://golfsimulatorforum.com/forum...hmt-with-bonus

[LEO MODE]

Apologies for the confusion in my sales post. I have just written my reasoning in that same sales post.

[Wizard of Coz]

Leo goes above and beyond for his tests. I've never calibrated any of my 3 units including your 2501 wbond . They all seemed the same to me.

[wbond]

Yeah mine seemed to read correctly for me, the one you bought and the one I have now. I’ll have to go read what he posted about the calibration.

[DirkDigglr]

So this thread is probably long dead but here goes...I have also questioned the club data from my GCQ - specifically face as at times the face-path or face-target data doesn't make sense given either the spin axis of the ball or initial horizontal launch direction of the shot. I do feel like the ball data is correct but I have no proof on that other that my gut feel as all my shots are indoor so I can't compare to range ball flight. anyways, today I hit 206 shots (irons only to eliminate any bulge issues in the calcs) using FSX Pro and I downloaded the data into excel to test the theory above about face-target relationship to horizontal start line of the ball. I assumed the horizontal start line AND the club path were correctly captured by the GCQ. I then compared the face-target using the formula above vs. the face-target as captured by GCQ.

Interesting that about 25% of these shots had a variance >2* which I found concerning. I realize this is a crude test and more things impact start line than what I am using but its a quick and dirty test and I felt a 2* variance was more than enough to allow for other factors I ignored.

assuming the club path and horizontal launch angle are correct, there are clearly some shots where the face-target as captured by the GCQ is incorrect. one 7 iron example:
Horizontal Launch direction: +1.5
Path: -0.4
Face-to-target: -3.0
Face-to-path: -2.6
Spin axis: -0.9
Ball finished +2.8 yards (right) of target line

so, now I am wondering should I get my GCQ calibrated if I can? its a shame to have paid for the the club data if you have concerns about its accuarcy. does anyone have any experience in this?

[GullLakeMi]

Anything common about the 25% with variance?

My 16 year old, beginner golfer, son occasionally gets some data I can't explain. He delivers the club (irons) with > 5% in-to-out path and even bigger face variability. (He is a strong tennis player, so I think he fights a dominate trail arm/hand.) The flight path from FSX 2020 doesn't always make sense to me compared to the #'s.

I certainly have variability, but not to his degree. I have never been concerned about my shot data except for recently where I've had 4 Bridgestone balls crack. That provides some crazy #'s although, once you know the ball is cracked it seems accurate as well.

[ENadeau]

You could always capture shot data and shoot it over to Foresight support. They’ve been pretty responsive lately.

[DirkDigglr]

Yeah, I have been in touch with them and they are responsive. The concern is that Foresight Canada isn't able to test the machine. they said they would have one of their people hit shots on it and based on that, determine if felt something was wrong. they did this for me a year ago and they felt it was working ok (this was before I saw this horizontal launch test).

I would prefer a more scientific approach to testing the machine vs. a human hitting shots! but they are going to connect with Foresight USA on this to see what it would cost to get the machine calibrated and how long it would take.

[delaloi]

@Dirk: did you consider eliminating shots from your sample that weren't struck out of the middle? I just disregard GCQ data for shots that were not struck well; for some reason results just seem crazy at times. Also, off-center hits should affect start line less with irons than a driver but this still might be causing some effect.

Perhaps more important, if you are going to take such a close look at start line, playing indoors, you need to be really careful that your alignment is correct and consistent. When hitting into a screen you can't tell that precisely where the ball started. Try hitting a few on video DTL so you can see where the ball actually strikes the screen, and compare that to the GCQ data.

I have no specific explanation for the data set you give, indeed weird, but my guess is that with those controls, you will be able to figure this out and it's not a matter of GCQ calibration.

[DirkDigglr]

thanks for your thoughts on this. A few things on this: 1. I only used irons to remove any bias that hybrids, woods, etc may provide given their face has bulge. 2. the centre strike shots still show some weird data so that doesn't explain it - the example I listed above was a perfectly hit 7i that flew 150 and was only 3 yards offline on landing. the iron lie angle was almost zero as well. 3. I use the quad alignment stick each session to ensure the unit is measuring the angles correctly. 4. I have DTL cameras and it showed the start line to be about where the GCQ unit said start line was.

so unfortunately that doesn't appear to be it. Foresight Canada is still chasing down the cost to get the unit re-calibrated in the US so it sounds like this may be something I could do (price dependant of course).

cheers!