ShotMarker - the personal 8-mic e-target

[adamjmac]

The ShotMarker is just about ready to ship! We are completing the first few units now and have just put up our new online store where you can place an order, see prices for spare parts, etc.

https://shotmarker.myshopify.com/

There has been a lot of new info added to the main website as well: theshotmarker.com

 

[lawrence97]

Adam, how are these tablets looking under direct sunlight? Is there one that offers a screen bright enough? Or is a shade of some sort needed?

Do the amazon fire tablets or kindles work with your system?

 

[adamjmac]

Adam, how are these tablets looking under direct sunlight? Is here one that offers a screen bright enough? Or is a shade of some sort needed?

Do the amazon fire tablets or kindles work with your system?

Indoors they seem quite comparable to my Ipad, but I'm actually going to take one to the range tomorrow and I'll report back. Maybe take a photo if I can get one in the sun.

 

[Alexander-M]

Adam,

Have you run any tests where you shoot a (paper) target, and compare that paper target with the ShotMarker displayed target? Do you have any pictures of such 'shot' paper targets and corresponding ShotMarker displayed targets that you could share with us?

Thx!

Alex

 

[adamjmac]

Adam,

Have you run any tests where you shoot a (paper) target, and compare that paper target with the ShotMarker displayed target? Do you have any pictures of such 'shot' paper targets and corresponding ShotMarker displayed targets that you could share with us?

Thx!

Alex

Yes, I ran a comprehensive test back in December. There's 143 shots measured to the millimeter. Here's the paper and the combined plot.

The error SD is 1.4 mm X and 1.2 mm Y. (0.055 inches). Reducing the error any further comes down to target frame construction. The sensors are no longer the problem. I did a lot of work to make sure of that. The MEMS sensors have a much faster response time compared to what has historically been used for e-targets, increasing repeatability, and the sensor units are one rigid piece so there's no flex in the housing. The sensor spacing is only 100 mm which allows a rock solid single unit and is really a better approach. Also, many of the accuracy issues associated with other sensors on the market do not apply. I decided to go with these sensors for good reason.

Edit. You may notice a couple of shots missing in the top left region. These bullets hit the cardboard a few inches from the sensor and the vibration ruined the reading. The sensors at the time were too sensitive to this and have been fixed. Every shot that was reported by the system at all is on this plot, and the worst case of them all was 4 mm (0.16").

 

[Alexander-M]

Excellent, Adam!

Based on this test (143 shots - definitely a statistically signifcant sample) your system appears to show better correlation (than other systems) between the actual Points-of-Impact and their electronically 'interpreted' locations .

Thank you -
Alex

 

[Heman]

Hi Adam,

Hope all is going well, haven't spoke with you since you were helping SMT write code. Was just wondering if you could possibly post all the data, specifically could we possibly have the display data, just not the target data? Also I noticed in the picture below a few shots were not plotted. Why was this?

 

[adamjmac]

Hi Adam,

Hope all is going well, haven't spoke with you since you were helping SMT write code. Was just wondering if you could possibly post all the data, specifically could we possibly have the display data, just not the target data? Also I noticed in the picture below a few shots were not plotted. Why was this?

Hi Shawn

The two on the upper left are the bad readings fired too close to the mic that didn't compute. The one on the bottom was a calibration shot not part of the group. The two on the right were fired at an extreme angle and not reported. At the time, I had a velocity filter of 2500 m/s (meters, not fps) on all chronos (prior to angle compensation). The left sensors reported velocities of 2600 to 3200 m/s for these two shots which exceeded the filter and threw away the shots. I do have the timings from these shots and I re-ran them without the filter at the time, to check they were right, and it was, but I didn't add that solution back into the spreadsheet.

See, this is not an ideal test case meant to show off. This is my first and only R&D test. I fired 200 shots at angles +/- 30 degrees at 25 and 100 yards. I was trying to stress it to find problems, and I found some, investigated, and fixed them. I also was running two TwoBox Chronos and testing the velocity accuracy - that's why there's so many shots in the center. It is what it is.

The plot overlay is the measured and reported shots, not just the reported shots. I measured them all, entered the values, corrected for calibration shift, and then plotted both as an overlay. There was a slightly stretching due to calibration of the temperature sensor but I didn't correct for that. I could spend a day or two working on a perfect ideal condition test case and then post that with an even slightly better accuracy claim, but it's not worth the time. And I don't think it would be any more trustworthy marketing material anyway.

 

[adamjmac]

Check it out, you can see right on the cardboard. #70 and #71, both fired from the far right, marked "25 yd sweep" because I knew when I was numbering the shots it was the one that didn't report. Here's also the plot of side angle measured on each shot, to show you how it was tracking my shooting position. Unit is radians of side angle. The angle measurement is accurate within 0.005 radians (0.3 degrees).

 

[6ShotsOr5?]

Wow, this is a really cool product. The telemetry method sounds impressive. Tell us a little more about the downrange velocity measurement (or calculation?). I’m having trouble understanding how those sensors are measuring velocity. Are you measuring the sound decay after impact - like measuring Doppler shift? Or is it actually measuring time of flight and then calculating average velocity and working back from there? Or is it something else?

 

[adamjmac]

In each corner of the target there are two sensors spaced 100 mm in front of each other. The sound hits both and the time between gives you the velocity. We need all four corners to deal with the fact that the incoming angle is not straight on. Based on all four velocity values you can determine the angle and the true velocity.

With this implementation the velocity accuracy is about 5 fps.

 

[6ShotsOr5?]

In each corner of the target there are two sensors spaced 100 mm in front of each other. The sound hits both and the time between gives you the velocity. We need all four corners to deal with the fact that the incoming angle is not straight on. Based on all four velocity values you can determine the angle and the true velocity.

With this implementation the velocity accuracy is about 5 fps.

So then when using in a ballistics program you enter the velocity and tell it the chronograph is 1000 yds from the muzzle instead of at the muzzle or 10 ft or whatever?

 

[adamjmac]

So then when using in a ballistics program you enter the velocity and tell it the chronograph is 1000 yds from the muzzle instead of at the muzzle or 10 ft or whatever?

I suppose, if your program can do that, that works. What I do is just find the MV that makes the down range velocity work out. If you have the right BC (which is not always the BC it says on the box), and temperature then that should be close to the right muzzle velocity.

Example. Yesterday I fired a new load, 215 Hybrids at 900 meters. Down range velocity was hitting at 1520 fps. Back calculated muzzle velocity was 2615, which seems about right.

 

[tvaught]

@adamjmac

If someone has a tech issue that your setup directions don't address, or they need tech support is there a phone number to call?

What is the warranty policy/terms?

Why your system vs the SMT Solo?

 

[tvaught]

Soliciting anyone that knows the warranty terms/policy and the product support plan. Is it to email Adam? I've sent an email requesting this info 2 weeks ago. Then I posted these questions hoping to get a response here. I haven't gotten a reply. Thanks.

 

[adamjmac]

Soliciting anyone that knows the warranty terms/policy and the product support plan. Is it to email Adam? I've sent an email requesting this info 2 weeks ago. Then I posted these questions hoping to get a response here. I haven't gotten a reply. Thanks.

Hi,

Everything will be covered for warranty for 2 years, for function under normal wear and tear, not covering if you drop something or shoot it. If you have any specific questions please send me an email at adamjmac@gmail.com

PS. I may have missed your email but I do believe I've responded to all emails. Send me another email and I will certainly respond within a day.

 

[savageshooter86]

Hi,

Everything will be covered for warranty for 2 years, for function under normal wear and tear, not covering if you drop something or shoot it. If you have any specific questions please send me an email at adamjmac@gmail.com

PS. I may have missed your email but I do believe I've responded to all emails. Send me another email and I will certainly respond within a day.

Adam is very fast to respond to email. My unit should be one of first to ship. I’m ready to start practicing like I was in a match

 

[ED3]

Adam is very fast to respond to email. My unit should be one of first to ship. I’m ready to start practicing like I was in a match

YEP I was curios to learn where I stood on the list.
While I was somewhat hesitant to bug Adam, as I suspect he's busy working on the units, I did email him, and he responded within the hour....early June...

 

[m1jeff]

Guess I better email him too...

Edited to add that I got a reply in 15 minutes.

 

[gilmillan1]

is there a video of this machine in action? I am interested in a set.