SkyTrak Launch Monitor

[Maverick]

http://www.skytrakgolf.com/

iPad app:

https://itunes.apple.com/us/app/com.sporttrak.skytrak/id876548058?mt=8

[Mike Z]

Zmax - thanks for that info. Question: Does the unit need to be level to gravity or to the hitting surface? My skytrak is on the hitting surface which I assume to be level to gravity but the unit is level with the surface. I will check both tonight, but it bears to reason that if the unit is level to the hitting surface (even if both are off slightly to gravity) that the launch angle would be OK.

[hks8888]

just did a test in my house with new balls with the most of the white of the ball facing towards skytrak.
15-19 is 56 degree
20-24 is my pw
25-29 is my 9 iron

i was actually starting to hit a baby draw with my shots probably because i was swinging harder. all of the club shots are about 10-20 yards shorter than normal.

Those numbers are not acceptable!! The company should do something.

[hks8888]

I can confirm the SkyTrak's LA is spot on. LA is actually one of the easiest parameters to measure. This was verified using ProTee's Vertical camera and compared with the GC2. Now having said that, the user must make sure the SkyTrak is completely level. I would suggest using a small carpenter's level. If the unit is not level by 2 degrees, the LA readings will be off by 2 degrees, which will of course affect carry.

Is it supposed to do the auto leveling?

[hks8888]

New video demo just landed on youtube 8 Mins long. https://www.youtube.com/watch?v=3j-773laKoc

Just watched it. I like the graphic for target practice and closest to pin. If the short iron issue is resolved, it would be almost perfect for me.

[nyb72]

Just watched it. I like the graphic for target practice and closest to pin. If the short iron issue is resolved, it would be almost perfect for me.

How short can you make the target practice or closest to pin? A video of short shots would be really interesting. As a previous poster had mentioned, it seemed like all the videos are at 150 yds or more.

[pctekbr]

I don't know what the columns on that screenshot are, or I would do it myself, but it would be interesting to plug the ball data numbers into the flight scope optimizer and see what flight scopes model predicts and compare.

http://flightscope.com/products/trajectory-optimizer/

from left to right:
ball mph, club mph, launch deg, side deg, back rpm, side rpm, offline yds, carry yds, roll yds, total yds

i am pretty sure you can disregard club mph. those seem to be way off with the lower clubs.

[bkcorwin]

So based on shot 25 the flighscope trajectory optimizer has a carry of 137. So there it seems there is a discrepancy not necessarily in how the data is being captured, but in the flight model.

[fhann]

I checked the data on shot #15 (sand wedge) on my trajectory software and I get a carry distance on my software program showing 105 yards based on 70 degrees temperature and at seal level elevation. Seems pretty close to the output from the Skytrak software/hardware.

I also checked the clubhead speed that one should expect for the ball speed measured and my trajectory software shows a clubhead speed of 90 mph is required for the ball speed that you had measured, basing that upon a pure strike of the ball in the centre of the clubface to maximize ball speed. I get a spin value of nearly 12,500 rpm backspin in my trajectory software based upon your angle of attack of -1.7 degrees which is considerably higher than your recorded value of around 9000 rpm. I would be expecting around 12,000 rpms backspin being produced when correctly striking a 56 degree sand wedge, (i.e. expect about 1000 rpms/per clubhead increase using 6 iron loft of 31 degrees and 4 degrees separation between clubs. So, one should expect about a 6000 rpm backspin number for a six iron, 7000 rpms for a seven iron, 8000 rpms. for an 8 iron, etc.)

Frank Hann
Engineered Golf
AGCP clubfitter/repair person

[bkcorwin]

Which software are you running? I just ran shot 16 and I get ten yards longer on the flightscope model as well.

[bkcorwin]

I would also add that I don't think people should freak out about this. So the results from flightscopes optimizer, fhanns result, and skytrak show about a ten yard range on short shots based on the same capture parameters. So, seems like it should be an easy fix. In terms of evaluating I'd be interested in seeing a distribution of the actual measured parameters from say 5-10 shots that with someone attempting the same shot. EG how repeatable are the measurements. Assuming the measurements are good, seems like any bias will be an easy fix.

[pctekbr]

So based on shot 25 the flighscope trajectory optimizer has a carry of 137. So there it seems there is a discrepancy not necessarily in how the data is being captured, but in the flight model.

i am thinking this is good news. the data it is collecting is correct. it is just not showing the output incorrectly. This should be easily solved with updates to the app with new calculations. i just ran some numbers with a six iron and they were very close to what flightscope had. so, i just realized that i am not crazy. woo hoo.

[bkcorwin]

We must have posted at the exact same time! I just made a very similar comment right above you

[Maverick]

Zmax - thanks for that info. Question: Does the unit need to be level to gravity or to the hitting surface? My skytrak is on the hitting surface which I assume to be level to gravity but the unit is level with the surface. I will check both tonight, but it bears to reason that if the unit is level to the hitting surface (even if both are off slightly to gravity) that the launch angle would be OK.

It needs to be level to gravity.

[Maverick]

Is it supposed to do the auto leveling?

Not sure but I think they claim that it does. Maybe check with SKyTrak or the specs on their website.

[Mike Z]

bkorwin - Very interesting exercise. Using data from my 6 or 7 and 4 iron the results were very similar (within a yard and a half), using data from a wedge shot Ball speed 67, launch 26.1, horiz launch -5.5, spin 8558, side spin (735 on ST 749 or 4 deg in FS optimizer......) gave carry of 79.5 FS and 66 on ST. 80 sounds about right for what I was trying to do. Did similar with I thin a 9 iron and came up 13 yards short on ST. IF I take the flightscope flight model as a given and I have been on a flightscope enough to be comfortable with it, then I can conclude that the good news is that is appears that ST is capturing the data accurately and its the flight model that needs tweaking. I will run some more shots through both at some point to see what I can tell and see if I can find some sort of correlation. Intersting note is that 13 seemed like the difference when the horizontal LA was to the left and 9 when it was to the right, with 1 or 2 outliers. Its a real pain that my app is not labeling the clubs I am using. as it makes this hard to go back and do. Wondering what would happen if I hit a wedge set to 7 iron? Is the flight model the same for that club and for a wedge? Also wondering if I could see some sort of relationship between variables and difference if I plotted enough items out. I still think that ST is super useful knowing that the yardage under is somewhat constant.