Random shanks

[Ianm711]

May have been posted in the past but curious if anyone has come across this. I'm a long time golfer new to building my own sim though. Every once in a while I will get a shot that just completely shanks left or right even when I hit directly in the middle of my screen.. This has happened on both skytrak and WGT(More often on wgt) and its really frustrating starting par or over a few strokes after a couple holes and that one shot roles around that completely destroys my score for that hole. I plan on upgrading to TGC very soon I know they have better ball dynamics so that should be more fun but was curious if anyone else has come across this same issue? I had a ball tray next to my hitting mat behind me and moved that hoping that's the fix will find out If it was that the more shots I put into it.
thanks in advance for any feedback.

[Venom]

It happens to me too on TGC so don’t think that will solve the problem. It doesn’t happen all the time so I don’t know how to solve it. I don’t really see it when I’m on Skytrak’s range.

[colinjm18]

I use to get them when I had my skytrak and now get them with the mevo+. Only get them in TGC’19 so maybe the date is getting mixed then going from machine to tgc.

[Ianm711]

Must just be what's gonna happen from time to time using a launch monitor thanks for the input atleast I know it's not just my unit now.

[Morini]

This typically happens for shots that are at the edge of Skytrak's vertical field of view. Typically very low shots (woods), and very high shots (wedges). It is made worse if Skytrak is at wrong height. It should be same heigh as hitting surface. It would help to move ball two inches or so to the right (away from screen) for woods, and maybe one inch to the left for wedges.

[Ronsc1985]

This happens because the ball pictures are out of the Skytrak field of view. This can happen with any club. This problem was readily seen in Vector Pro LM's which were essentially the same methodology as a Skytrak.

The software has to draw a circle around each of the two ball images to calculate their centroid..The distance between these centroids is used in the calculations of ball speed, launch angle etc. If Skytrak would display these images as the Vector Pro did you would see the outlines are really screwed up and you would readily discard those data points.

In order to minimize these situations move the ball back a bit for high ball speed clubs like drivers and forward for low speed clubs like wedges.

Better and more expensive camera LM's, like Foresight models, eliminate this problem by having many images (7 to 12) for each shot instead of the two Skytrac produces. The expensive comes from having high speed cameras among other things.

Skytrac has good bang for the buck. As usual there is no free lunch. If you want better prepare to have you wallet lightened

[Travrav40]

I have them all the time, but wait that’s my swing ;-)

[Morini]

As Ronsc1895 states, it typically happens when the imagers only get partial view of the ball. Usually due wrong height and/or extremely high or low trajectory shot and/or poor case fit.

As Ronsc1895 recommends, moving the ball back for woods and forward for wedges would help. I disagree that this is due to speed, and believe that it is entirely due to trajectory causing ball to go out of vertical field of view.

[Ronsc1985]

As Ronsc1895 states, it typically happens when the imagers only get partial view of the ball. Usually due wrong height and/or extremely high or low trajectory shot and/or poor case fit.

As Ronsc1895 recommends, moving the ball back for woods and forward for wedges would help. I disagree that this is due to speed, and believe that it is entirely due to trajectory causing ball to go out of vertical field of view.

The reason speed matters is the unit has a fixed time between the two ball pictures. If your ball speed is fast enough you may not have enough time to capture the second picture successfully.. If the ball speed is slow enough you may not capture the second picture before all or part of the ball goes out of frame vertically.

This is not idle speculation and was visible on a Vector Pro where you could see the composite ball images captured. You could also specify the time between exposures to help with the problem. Moving the ball forward and aft can help getting both pictures in frame since you cannot change the time between pictures.

[Morini]

I believe the Skytrak is based partially on the Accusport patents, but not sure. Regardless, what has changed is that the laser curtain is used to trigger, so where the ball starts from doesn't matter (except for trajectory of course). I believe the vector was ... sound triggered? Also that it used only 1 camera and 8 strobes. So a bit different.in that moving ball for the vector does indeed change the balls horizontal location in shots.

Skytrak captures one image per camera 4.14 milliseconds apart. The second camera makes it a bit easier to capture fast shots. It can accurately read ballspeeds over 200 mph, so running out of horizontal view is not an issue.

[Morini]

The reason speed matters is the unit has a fixed time between the two ball pictures. If your ball speed is fast enough you may not have enough time to capture the second picture successfully.. If the ball speed is slow enough you may not capture the second picture before all or part of the ball goes out of frame vertically.

Yes, the time is fixed, 4.14 milliseconds.

Moving the ball does not give more time to capture the second picture. The unit starts the capture process the instant that the ball crosses the laser curtain. In terms of keeping the ball in horizontal field of view, it doesn't matter if the ball starts one inch or one yard or 10 yards (don't try this) away from the dot. It starts when it crosses the curtain.

When the ball crosses the laser curtain, the light scattering off the ball is captured by the IR receivers, and the wave form is analyzed in order to estimate the ball speed. This is then used to calculate when to fire the strobes ... and yes, it will fire the first one very quickly for high ball speed ... but as mentioned, this process starts after it crosses the curtain. Moving ball position will not change the timing one iota, and therefore will also not change the horizontal location of the ball in the images one iota. It will however change the vertical position of the ball ... obviously.