Thank you Stephen,I have spent time to research what is available in US and across the Ocean. My impression is that Chronographs with two pass-through triangles, with or without additional light are bulky, not reliable and difficult to operate at shooting range. New design like Chrony MK3 and Combro especially, are very compact, easy to operate and more reliable as far as lighting condition concerned. It’s definitely way to go. I hope someone in US will introduce similar design. I have purchased Chinese e9800-X3200 with two rows of receivers and transmitters for $34.75. Delivery in US is up to 39 days. Will learn and possibly use as a base to design my own application. Please take a look at links bellow. Do you have any of them?1. $83.55 COMBRO CB-625 Mk4 Air Rifle Gun Chronograph Chronoscope Ft/lbs Shooting+ Aligner, Made in UK. It has a cable interface to PC and Android. Very good design easy to attach/remove. https://www.ebay.com/itm/COMBRO-CB-625-Mk4-Air-Rifle-Gun-Chronograph-Chronoscope-Ft-lbs-Shooting-Aligner/331701266190?_trkparms=aid%3D222007%26algo%3DSIM.MBE%26ao%3D1%26asc%3D20140131123730%26meid%3D398d3ceb3f62409386fd696b793a55ed%26pid%3D100167%26rk%3D1%26rkt%3D15%26mehot%3Dpp%26sd%3D371495889151%26itm%3D331701266190&_trksid=p5411.c100167.m29402. $76.76 Emerson E9700 form AliExpress . It has some sort of interface, but nothing in very basic description about software https://www.aliexpress.com/item/EMERSON-E9700-shooting-chronograph-Speed-Tester-with-Pixel-Tactical-Airsoft/32796623119.html?spm=2114.10010108.1000014.8.275393fb0YAlp2&traffic_analysisId=recommend_3035_null_null_null&scm=1007.13338.80878.000000000000000&pvid=2c346cbb-5799-4bdb-9f41-82c9c6ab5368&tpp=13. $283 Air Chrony MK3 Max from Czech Republic. It seems to be very good but expensive. https://www.air-chrony.com/en/6-shooting-chronograph. It also sold by AirGun Buyer in UK. For GBP 139http://www.airgunbuyer.com/Showproducts.asp?cat=Chronographs&SubCat=Shooting%20Chrony%20Chronographs#R2A%20Ballistic%20Chronograph4. $34.75. Frees hipping Muzzle velocity anemometer / velocimetry / valence e9800 X3200. Very basic display of speed. I https://www.aliexpress.com/item/Muzzle-velocity-tester-valence-e9800-X3200/32810999374.html
Agree they are bulky. Don't agree they are not reliable. My Prochrono works outside or inside no issues with it picking up shots. You do have to use the lights or the sun shades though which makes them bulky.The further apart the sensors the easier it is to make them accurate. So compact may mean less accurate if all other things are equal.
Will learn and possibly use as a base to design my own application
Stephen,Here is my two cents. The Combro CB 625 is very portable, attached to the barrel and has 2.353 inch distance between sensors. Let’s round distance to 2.5” for easy calculation. Suppose a bullet speed is 6000 f/s=72000 inch/s. I takes 34.72 microsecond /28.8 kHz to travel from front to rear sensor. The leading edge of pulse comes from front sensor, falling edge from rear sensor. At 2000 f/s, range of air rifle, a pulse is 104.16 mk/sec=9.6 kHz. The 741 timer is more than capable to capture these pulses. Arduino will also capture it. When we are talking about resolution we really mean a repeatability. With good repeatability calibration is easy. System’s repeatability comes from DAC resolution (10,12,16 bit DAC). Pulse repeatability comes from repeatability of sensors, including transmitter light stability, ambient light interference, percentage of light beam blocked by passing bullet, etc. Therefore, the unit permanently attached to the barrel (CB 652) will have a better repeatability than free standing MK3. Designer of MK3 has realized that and offered an additional barrel support bracket, still it is not better and will not be better than attached to barbell system rest of all equal. I think that DIY Unit is reality. Arduino is an excellent platform along with excellent MS studio IDE. So, what did I miss?
Quote from: RAJOD on April 26, 2018, 01:23:05 PMAgree they are bulky. Don't agree they are not reliable. My Prochrono works outside or inside no issues with it picking up shots. You do have to use the lights or the sun shades though which makes them bulky.The further apart the sensors the easier it is to make them accurate. So compact may mean less accurate if all other things are equal.OK, few things to note - accuracy due to distance between sensors - a fast clock speed negates need for a long distance - i.e. long distance and 8 meg clock rate is going to be worse than short distance and 32 meg clock rate - downside is fast hardware is more expensive than slow hardwareInfra-red transmitter/detector is superior as no light source is required at all - the transmitter emits infra-red, the detector receives the infra-red ... simple. The 6 LED array does add complications over a single LED (as the pellet causes only a small change - other LEDs unaffected by pellet), but it looks like they solved thingsOnly thing better than an infra-red chrony would be a laser chrony, and that can't be done at a reasonable cost
If they had a way for the user to calibrate this would be moot.
Agree they are bulky. Don't agree they are not reliable. My Prochrono works outside or inside no issues with it picking up shots. You do have to use the lights or the sun shades though which makes them bulky.The further apart the sensors the easier it is to make them accurate. So compact may mean less accurate if all other things are equal.Quote from: algun on April 26, 2018, 12:36:08 PMThank you Stephen,I have spent time to research what is available in US and across the Ocean. My impression is that Chronographs with two pass-through triangles, with or without additional light are bulky, not reliable and difficult to operate at shooting range. New design like Chrony MK3 and Combro especially, are very compact, easy to operate and more reliable as far as lighting condition concerned. It’s definitely way to go. I hope someone in US will introduce similar design. I have purchased Chinese e9800-X3200 with two rows of receivers and transmitters for $34.75. Delivery in US is up to 39 days. Will learn and possibly use as a base to design my own application. Please take a look at links bellow. Do you have any of them?1. $83.55 COMBRO CB-625 Mk4 Air Rifle Gun Chronograph Chronoscope Ft/lbs Shooting+ Aligner, Made in UK. It has a cable interface to PC and Android. Very good design easy to attach/remove. https://www.ebay.com/itm/COMBRO-CB-625-Mk4-Air-Rifle-Gun-Chronograph-Chronoscope-Ft-lbs-Shooting-Aligner/331701266190?_trkparms=aid%3D222007%26algo%3DSIM.MBE%26ao%3D1%26asc%3D20140131123730%26meid%3D398d3ceb3f62409386fd696b793a55ed%26pid%3D100167%26rk%3D1%26rkt%3D15%26mehot%3Dpp%26sd%3D371495889151%26itm%3D331701266190&_trksid=p5411.c100167.m29402. $76.76 Emerson E9700 form AliExpress . It has some sort of interface, but nothing in very basic description about software https://www.aliexpress.com/item/EMERSON-E9700-shooting-chronograph-Speed-Tester-with-Pixel-Tactical-Airsoft/32796623119.html?spm=2114.10010108.1000014.8.275393fb0YAlp2&traffic_analysisId=recommend_3035_null_null_null&scm=1007.13338.80878.000000000000000&pvid=2c346cbb-5799-4bdb-9f41-82c9c6ab5368&tpp=13. $283 Air Chrony MK3 Max from Czech Republic. It seems to be very good but expensive. https://www.air-chrony.com/en/6-shooting-chronograph. It also sold by AirGun Buyer in UK. For GBP 139http://www.airgunbuyer.com/Showproducts.asp?cat=Chronographs&SubCat=Shooting%20Chrony%20Chronographs#R2A%20Ballistic%20Chronograph4. $34.75. Frees hipping Muzzle velocity anemometer / velocimetry / valence e9800 X3200. Very basic display of speed. I https://www.aliexpress.com/item/Muzzle-velocity-tester-valence-e9800-X3200/32810999374.html
The USB port is not recognized by PC and no link to get PC software. Does anyone have used E9700.
QuoteYea that could be the best budget chrono.It's well made - those pillars are solid brass with black plastic decorative sleevesI may make a metal or heavy perspex fascia to protect the plastic, but so far I haven't shot itIt comes with a mini tripod - but I use a full size camera/video tripod with it as it has a mounting bush underneathIt's supposedly better than 1 percent accurate
Yea that could be the best budget chrono.