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Posted: Thu Feb 09, 2006 1:12 am
by Spencer C
Re 10m EST targets;

I train our range staff to check the movement of the paper strip for each shooter during the start of AP matches (a bit tricky for the first few shots, as the paper curls until there is enough weight of paper strip to hang down) and ROUTINELY check every allocated target during the match - proper movement of the paper strip is pretty obvious.

There is no need to reshoot all the match if there is a paper jam, only the shots after the jam. The shooter is allocated another bay and additional sighters.

The major cause of jammed paper strip has been with low velocity pistols - lordy knows why, all the pistols tested give better accuracy at around 400fps (+) and at this velocity there are very few jamming 'tears'

Re 'guests' comment "...He was frustrated by the scores the system had been returning though" - if the target was returning a score, it would still be within 2.25mm of the actual value; not the difference between a 10 and an 8. 7, or whatever.

Regards to all

Posted: Thu Feb 09, 2006 1:28 am
by Spencer C
to (a different?) guest:

"...To calibrate the targets, a guy with a rifle stood in front of the targets, about 5 meters away and fired a shot in the middle. They hit a button and called that a 10.9. C'mon."

Do you really think was this a 'calibration' exercise?

Sius Ascor substitutes

Posted: Thu Feb 09, 2006 4:44 am
by the quark
Stewe, nov. 21 ยด05 you wrote:
[quote
The "MegaLink" system looked like (since only part of the "english" pages were written in, well, english, I can't be sure) the same technology as Sius-Ascor system.

Rolling paper backer, microphones in frame, etc. but with better software.

Looked promising at first glance . . . pricing and ISSF suitability would be issues.

Steve Swartz[/quote]

Our experiences regarding the MegaLink system leaves something to be desired, really.
There are problems in displaying several targets simultanously.Target displays are prone to "hang up" for several shots, then suddly showing all "misssing" shot values at once.

The Sius Ascor system is an expencive, but wellproven system. The MegaLink system is still in its infancy, and a flawless version might be well into the future, it seems.
This system has been tested in a few nationals in a scandinavian country, without much success.

I find the SmartScore interesting. Its low cost and simplicity is intriguing. The accuracy (repeatability) of the system might or might not be an issue, though.

Posted: Thu Feb 09, 2006 9:29 am
by Ed Hall
Spencer C wrote:
I train our range staff to check the movement of the paper strip for each shooter during the start of AP matches (a bit tricky for the first few shots, as the paper curls until there is enough weight of paper strip to hang down) ...
From someone who knows absolutely nothing about the system:

Can't you stick some paper clips on the leading edge to provide the initial weight?

Take Care,
Ed Hall
http://www.airforceshooting.org/
http://www.starreloaders.com/edhall/

Posted: Thu Feb 09, 2006 10:34 am
by David Levene
Ed Hall wrote:Can't you stick some paper clips on the leading edge to provide the initial weight?
It is actually pretty heavyweight paper Ed, they would need to be laaaarge paper clips.

The alternative that I favour is just to leaveabout 18" of paper hanging out of the bottom of the target from the start. It'll soon be there anyway once you start shooting. The other advantage is that it removes the tendancy to try tearing the paper off against the target box. If you are just a little bit over-energetic doing this you can pull the paper off-centre and away from the feed rollers.

It still doesn't matter how careful the range staff are on the initial setup, if you get too many shots into the target mask (just one if you are very unlucky) or a very low velocity pistol you are likely to have paper jamming problems.

Posted: Thu Feb 09, 2006 2:47 pm
by Ed Hall
Thanks David,

I wondered about starting with a long lead of paper, but figured there must have been a reason to have a short lead.

I guess it's good I'm not shooting in these. The CP2 I'm currently using will not make nice holes. I have the velocity up around 480 fps, but it often makes a 1-2 inch tear in the standard B40 from American Target. I haven't tried Edelmann targets yet.

I'm thinking I need a little work still anyway. The competition looked a bit tough when 580 couldn't even make the top ten in Munich.(smile)

Take Care,
Ed Hall
http://www.airforceshooting.org/
http://www.starreloaders.com/edhall/

Posted: Thu Feb 09, 2006 8:00 pm
by Spencer C
Can't you stick some paper clips on the leading edge to provide the initial weight?

Not really needed Ed. If the paper strip is torn off at the bottom of the box for the start of a relay, the paper feed is obvious for the first few shots - it's between the 8th and 15th shots (approx) that the paper curls and makes things difficult, after that the weight of paper out of the target box will make it hang down.
With a little experience the ROs can pick up the 'jiggle' even when the paper is curled.

One genius during construction of the Sydney range wanted to have the paper strip run behind a screen to make things look neater!

Regards

Posted: Thu Feb 09, 2006 11:25 pm
by Ed Hall
Thanks Spencer,

I think I have an idea of the setup. I wonder why they haven't made an extra sensor to validate paper advancement... Anyway, thanks for the info.

Take Care,
Ed Hall
http://www.airforceshooting.org/
http://www.starreloaders.com/edhall/

Posted: Fri Feb 10, 2006 12:00 am
by Eddy
Spencer C wrote:to (a different?) guest:

"...To calibrate the targets, a guy with a rifle stood in front of the targets, about 5 meters away and fired a shot in the middle. They hit a button and called that a 10.9. C'mon."

Do you really think was this a 'calibration' exercise?
I know it was. I asked them what they were doing.

Posted: Fri Feb 10, 2006 1:58 am
by Spencer C
Eddy

could it be that this falls into one of two categories:

- there was a lot more going on than just a shooter firing at the centre of the target from close range (measure the hole position and compare with computer calculations - from what I heard of this incident I doubt it) and see what the moniter score was, or

- we have a saying in AUS that I have heard seems to translate into every language about "I'm from the government; I'm here to help you" that I am told some people do not believe is a joke.

Regards

How They Work

Posted: Sat Feb 11, 2006 7:57 pm
by Benjamin
1. It doesn't matter how "sensitive" the microphone is, to measure to the nearest 1/10 point or better. The speed of sound is about 1100 ft/second. At 20 KHz frequency response (any good microphone), the length of a complete wave form is about 1100/20,000 = .055 ft = 0.66 inch. However, the leading edge of that waveform is a lot more precise than that. If you have a computer that can read the timing of that edge to the nearest 1/4 micro-second (easy with a typical cheap micro-processor running at 16 MHz clock speed), that will resolve the distance from pellet to microphone to the nearest .0033 inch. The distance between air rifle rings is 0.1 inch, so the best this system could measure (if everything is working correctly) would be about 1/30 of a point on the air rifle target, and proportionately better than that on larger targets - good enough.

2. Calibration of the microphone system is probably not perfect compared to the white cover sheet. That's OK as long as it's reasonably close, they make adjustable sights on the guns so you can compensate for it. If you find during sighter shots that your gun is shooting left 1 ring, as scored by the electronic system, then adjust your sights so good shots go in the middle. It doesn't matter whether the pellets are actually going in the middle or not, the important thing is that the electronic score goes in the middle when you make a good shot, and that other shots are measured with the correct variation from the electronic center.