[H&K]Ravizzone Posted November 18, 2005 Report Share Posted November 18, 2005 Didnt work, rtl70 was not found. Link to post Share on other sites
Pendra Posted November 18, 2005 Author Report Share Posted November 18, 2005 Working with not native components at 4 o'clock in the morning... Thanx for pointing out. You can dl the missing file from here: http://www.variagame.hu/rtl70.bpl Copy it to your Windows\System32 folder http://www.variagame.hu/SCrono_v05.exe I decided to change the name as well, to reflect that it is just an alpha version. Hopefully nothing else is missing. Forgot to mention, it is for WinXp Link to post Share on other sites
[H&K]Ravizzone Posted November 18, 2005 Report Share Posted November 18, 2005 vcl70 was not found lol. Link to post Share on other sites
Pendra Posted November 19, 2005 Author Report Share Posted November 19, 2005 Ahh, I think I have to set something to include all the needed files. But anyway, it seems the program is not working right. I tried it with my guns and it produced all kind of mess as results. I think I will go back to experiment with the mic placement and the mic volume. Link to post Share on other sites
[H&K]Ravizzone Posted November 19, 2005 Report Share Posted November 19, 2005 Cool, thanks for working on this program, it should help out a lot of people who dont have a chrono. Link to post Share on other sites
Pendra Posted November 19, 2005 Author Report Share Posted November 19, 2005 Ok it seems I have the final solution: I was still unable to determine the exact moment the BB leaves the bullet, so I made a hack. I took 2 sheets of A4 paper and folded them in half. I put them onto the ground The reson I folded then is that thay can stand on their own, without falling back. I also layed down 2 book to anchor the papers, because the papers will start to move backward a little when you hit them with BBs. Don't shoot the books! Put the mic half way between them. Added some cloths to dampen the sound of the hit on the wall.  The whole setup looked like this from the top down  .................................MIC GUN-........|_Book......1m dist........|_Book........II-sound/hit damper  I got this type of waveform --<>-|>---|>--<>-- Notice the 2 peaks. One is the hit on the 1st paper, the 2nd is the hit on the 2nd paper. It is totally irrelevant when the BB actually left the barrel. You see 100% sure when it entered and left the range. As both markers are the same material, the amplitudo are almost the same. With the damper at the end, the BBs will not ricochet, so you can do it safely in your room. (I got more hits last night with the hit on the wall idea, than in a whole month.)  You can DL it from here: http://www.variagame.hu/SCrono.zip  I think the idea will not get any more accurate than this. Hm maybe if you increase the range between the sheets. And I hope you will not miss files BTW you gotta use 0.81 as distance for the sample files. Also included my AS calculator, just in case. Link to post Share on other sites
[H&K]Ravizzone Posted November 19, 2005 Report Share Posted November 19, 2005 Holy hell man nice work. Â Hey sid maybe you could test out the accuracy of his program with your chrono. Link to post Share on other sites
CombatEvolved Posted November 20, 2005 Report Share Posted November 20, 2005 hey if you are interested in reducing the error you can make a correction for the speed of sound...you can calculate your local speed of sound by doing the following:  speed = sqrt(1.4*287.05*T) where T= temperature in celcius +273.15 this will give an answer in m/s  hope this maybe makes the readings a tad more accurate! Link to post Share on other sites
Hissing_Sid Posted November 20, 2005 Report Share Posted November 20, 2005 TBH, I can't be bothered to go through the sums again (I'm sure you can do that for yourself ) but I think I calculated it that if you assume a 2m long "range", and the microphone mid-way along it, then the sound has to travel 1m to the mic. I seem to recall that this works out to about 1fps difference between absolute and corrected velocity. Hardly worth worrying about. Â Regarding the deal with shooting through paper, I wonder if it'll reduce the power since the BB has to punch through a sheet of paper which will, slightly, dissipate it's power? Link to post Share on other sites
Sale Posted November 21, 2005 Report Share Posted November 21, 2005 Someone just has to shoot his gun over a chrono with no obstacles, and then place one piece of paper (folded) between the gun and chrono. Only one because the second paper won't affect the result like the first one does. Â I would imagine that it differs a little bit depending on BB weight and velocity, but it would be accurate enough to measure if the gun is safe to skirmish or not. Â -Sale Link to post Share on other sites
Pendra Posted November 21, 2005 Author Report Share Posted November 21, 2005 I thought of this and added +2 m/s to the calculated speed. I tried my L85 springer (theoretically 0.5J) with .12 and .2. There was about 0.1J difference with the .2 giving the lower results. I think the power loss from the paper is related mainly to the speed of the BB, and less to the weight. The higher the speed the lower the loss. I will make that modifier variable in the new version. I want to incorporte a method which would calculate the speed online without recording the sound into a wav file. Plus add a ROF calculator. It is simple to do with the current code . Link to post Share on other sites
Hissing_Sid Posted November 21, 2005 Report Share Posted November 21, 2005 I haven't tried this yet but you might be able to correct for shooting through a sheet of paper by actually ADDING another one. Â Fire a shot through THREE bits of paper and calculate the velocity. Â Now shoot through TWO bits of paper. The difference is the power dissipated by a single sheet of paper. You can add this much to the 2-sheet results to give a corrected figure. Â Might work out. Link to post Share on other sites
Sale Posted November 21, 2005 Report Share Posted November 21, 2005 I thought of this and added +2 m/s to the calculated speed. I tried my L85 springer (theoretically 0.5J) with .12 and .2. There was about 0.1J difference with the .2 giving the lower results. I think the power loss from the paper is related mainly to the speed of the BB, and less to the weight. The higher the speed the lower the loss. I will make that modifier variable in the new version. I want to incorporte a method which would calculate the speed online without recording the sound into a wav file. Plus add a ROF calculator. It is simple to do with the current code . <{POST_SNAPBACK}> Â Keep in mind that some guns actually give different muzzle energy with different weight BB's. Typically a heavier BB will give slightly more muzzle energy. Â -Sale Link to post Share on other sites
Jimisin73 Posted November 22, 2005 Report Share Posted November 22, 2005 Anybody try 2 mics? Â Most of the software you are using will record in stereo (l and r) or 2 tracks soooo: Close mic the muzzle with a condenser mic (directional) and Close mic the back of the board (the board will act as a sound insulator) Â When you look at the wave forms you will see peeks on track one for the round leaving the muzzle and peaks on track two for the round hitting the board. The calibration on the programs themselves should work down to .001 sec. so it should be easy to figure out the speed as long as you measure the distance accurately. Â BTW I won't be testing this out as I'd be daft to shoot airsoft guns in my music studio, but it should work well let me know Link to post Share on other sites
bullzebub Posted December 15, 2005 Report Share Posted December 15, 2005 isnt it time to stickify this? :-) Link to post Share on other sites
bullzebub Posted December 15, 2005 Report Share Posted December 15, 2005 *strange browser behavor* Link to post Share on other sites
bjorn Posted December 16, 2005 Report Share Posted December 16, 2005 Yup i agree. I tried it out also and got pretty good results. Although the waveform the WE see in the sound programs is ver diffrent with diffrent guns. That made my SL9 a bit hard to calculate it but it got it finally. Link to post Share on other sites
Jimisin73 Posted December 16, 2005 Report Share Posted December 16, 2005 Cool guys...of course all this could be avoided by buying a $100.00 chronometer...LOL still a cool project though. Â Can you post any screen shots from your software, showing the waveforms and such? Link to post Share on other sites
bjorn Posted December 16, 2005 Report Share Posted December 16, 2005 Sure. Here you go. This is a waveform of 1 meter, Sl9, and spring is just above the forum limits. With a short barrel it should come into the limits nicely. The first red line shows where i started calculating and the last one is where i stoped. Link to post Share on other sites
pgup.dk Posted February 2, 2006 Report Share Posted February 2, 2006 How about wrapping a pillow around your gun except for the muzzle and the crack will be the muzzlebreak. Â The other only really noticable sound will be hitting the board. Â This rocks. I will try it tomorrow. Link to post Share on other sites
Hissing_Sid Posted February 3, 2006 Report Share Posted February 3, 2006 For those who want to give this a go, Visionviper knocked together a little program which saves you having to do the sums for yourself. Â You still need something like Audacity to actually figure out the BB flight time but this little program should help do the maths for you. Â Remember to give Visionviper some rep points if you think this is useful. SoundCalc.zip Link to post Share on other sites
bronney Posted February 3, 2006 Report Share Posted February 3, 2006 Thanks everyone for posting this timely thread. Exactly what I needed tonite. +1 Link to post Share on other sites
Pendra Posted May 27, 2006 Author Report Share Posted May 27, 2006 I reworked the SCrono. It is more simple and more stable. I included pics about my setup. It is very simple but effective. It also works with computer independent sound recording devices, such as MP3 players and CellPhones. However, you may need some computer skill to make decent quality recording with those things and convert them into wavs.  Get it from here: http://www.jovedelmigazolas.hu/xcom/files/SCrono07.zip  Oh and here is the ROF Cheking program I made earlier: http://www.jovedelmigazolas.hu/xcom/files/ROFC2.zip Link to post Share on other sites
dliberty Posted January 3, 2007 Report Share Posted January 3, 2007 where can i get some of this sound recording software you speak of??? is it free? id love to try this myself. Link to post Share on other sites
Stealthbomber Posted January 5, 2007 Report Share Posted January 5, 2007 where can i get some of this sound recording software you speak of??? is it free? id love to try this myself. <{POST_SNAPBACK}> From the link to Audacity on page 1 of this thread. Link to post Share on other sites
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