Bullet Speed Meter | Homemade Chronograph 

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Neat project. And I love the comments section with everyone's ideas. I often learn as much from the replies as I do from the video.

Another great video. I love how this followed on from the coil gun. Thank you for showing how to do a beam break and how to make a very simple rechargeable battery circuit.

amazing in the end my request was granted as a fan of coil gun experiments this is very useful

Interesting project, but LDR's are quite slow responding and this does vary between individual LDRs. Photo transistors would be better.

Awesome project as always!

Excellent project 👍

Very interesting project. Thanks.

your videos realy helped me build my own velocity measurement device.👍

Nice project!

Great video by the way, thanks!

THẦY MÒ CHÀO CÁC BẠN ĐAM MÊ ĐIỂN TỬ ADUNO

What about laser with lens make line, used for self-leveling or cross projectors, it will be better choice.

Really great idea! But few things: The distance between the sensors should be at up to millimeter precise and the sensor "arms" can be slightly rotated - all of that makes it really, really inaccurate. :/ Timing of the circuit will be off, because response time of the LDR is really bad (up to 50ms).

A while ago I have build a device to meassure the shutter speed of analog cameras. It turned out that many ldr's have a rather high responsetime to light (many of them over 50ms!). I ended up using reverse connected LED's because they respond faster to light.

тЫ КАК ВСЕГДА ШИКАРЕН! сПАСИБО ПАРЕНЬ!

wow very nice and simple project

It's an interesting project, like most of the projects you do. Seriously ... you do a great job. But I'm not entirely convinced of your choices on this one. - Photo resistors are slow, ms accuracy at best. - Photo diodes are extremely fast, ns accuracy, but they are not very sensitive. - Photo transistors are a bit slower, tens of ns accuracy, but they are more sensitive. So, either a photo diode or transistor would make more sense. Not sure why you are using a laser, since you've taken the lens off and defeated the advantage of having a beam. I'd just stick with an LED, possibly an IR LED with a matching photo diode. You'd have better results if you put the sensor and receiver closer together. I'm sure that an Arduino is adequate for this project, sigh! ... but is it really the best choice? Possibly a blue or black pill STM32 might make more sense, running at 72 and 100MHz respectively? Even a cheap ATTiny212 or similar at 20MHz, might make sense, since it's doing almost nothing anyway? (Both of these have support on the Arduino IDE ... if this is an issue.) Finally ... using 8 7-segment displays, when you have 'single digit' accuracy at best, seems a bit like overkill.

Awesome project! 👍

You're awesome man

Great work.

what does the program do to add a point to the result ? like for example 2.5 m/s 16.2m/s should change this part ? shift(0x03, digit_1); shift(0x02, digit_2); shift(0x01, digit_3); tone(Buzzer, 1000, 300);

An Ldr can take 2 - 50ms to detect something. I originally I used a remote control receivers sensor ,but when I moved up to an air rifle it wasn’t fast enough. I moved up to a IR photo diode with a response time of 9ns theoretically I could detect an air gun pellet doing 6000mph 😂

great project🙂

What sort of processor / timing circuit would it take to have 1 foot / second resolution (about 30.48 cm / second) over a distance of 4 to 6 inches ( 10 to 15 cm), with bullet speeds up to 4000 feet per second (1219 Meters / second)?

Useful idea

Thank you for another inspiring project! I wondered if the velocity of your coil gun would increase if you held it in place so that it does not recoil?

Have you ever tried measuring the length of your bullet and a single sensor in stead of 2? I would also recommend photosensors as recommended by others.

Ya intenté éste proyecto con infrarrojos y no me funcionó, muy interesante tu planteamiento, voy a volver a intentarlo pero siguiendo tu idea. Se me ocurren varias mejoras: Vi que venden lares que sacan una línea, como pos niveles láser y no es caro, quedará mar guay que ésa luz difusa. Y la otra idea es usar un opamp como comparador, lm358 por ejemplo y conectar cada serie de LDRs a un comparador, utilizando un potenciómetro para la referencia de tensión de ambos, así se podría ajustar en cada momento a la luminosidad del lugar con una sola perilla

Very cool.

well done

Tnk you very much it makes my life more easier...

Does it work in bright sun light 🤔 Would it use much mor power with a oled display, becourse often the red led light can't be read outsides.

Nice - but as you have already built the coil gun to be modular, why not add this as a final stage? You could even use the signal from the last accelerator stage's photodiode, and I see that you already have pre-drilled holes in the tube, so distance measurement would be more accurate.

Would it be possible to make a vertical version of this to measure vertical velocity?

Can you give me the links where I can obtain the parts and 3D printer files, arduino soft.

First time saw removing laser lense results a cool project 😋

Just wonder we can use this LDR outdoor. I would like to use for archery but I am afraid that the LDR will capture the sun light.

The speed of the ATmega328P ISR is about 4us. 136m/s is about 450fps and the distance looks to be about 6 inches which means the interrupt needs to detect within 1us. Isn't there a good chance you will get false or no readings?

Cool 👍🖖

Hi I watched your job with very interest bacause it's a bit of time that I have in mind to realize a similiar project but some questions occcour, 1) What about arduino response time I/O an if is it fast enogh to have a realistic measuraments. 2)external parassite light may inflouence foto resistance reading an may be should be shielded?

how about using oled 128x64 what should be edited? so that the number display is more interesting

Thanks

It's unique...

New Sub 👍‍ How did the measured speed compare to the theoretical?

Great project. In real world scenario the sensors and emitter will get coated, slowly, with lead dust - from the lead bullets. My question: how will the presence of lead dust affect readings ? Will there be a delay in response time or will there be no affect until the screen is totally obscured by the lead dust and readouts finally stops.

What is te projectil weight? You can measure its kinetic energy using E=m.v^2 and compare it with airguns.

You bought the pcb's from the pcb way ,and you bought a lot because the minimum buying protocol.so what do you do with the other pcb

Doesnt it make arduino unstable if its 5v rail is powered with 4.2v at best scenario and which varies between battery voltage 3.5v-4.2v?

Dude, I LOVE ❤️ your videos! Your coilgun is crazy, I would like to know how much your projectile weighs in order to calculate how much power it has in joules. I assume that your projectile weighs about 2g, with a speed of ~125m/s, that's about 16 joules!!! That's too much for playing airsoft 😮 I will try to build your coilgun and make it work with steel BB's 😀

Great job friend..... Did you manage a speed test with 10 modules ?

hello can i uses led white color bulb insted of laser diode

Cool

How fast can it detect ?

Very cool. If the capacitors are charged to 425, and the projectile velocity is 139m/s then it stands to reason that each module adds 27.8m/s to total muzzle velocity. 139m/s / 5 = 12.8m/s per module To break the sound barrier at 344m/s, does that mean that you can do that with just 12 of these modules? 344m/s / 27.8m/s = 12.37 Can you make much longer stages to account for the higher velocity? E.g. The first 5 stages are short since you're not moving the projectile all that fast. But with a longer barrel, the first five modules only take up about 7". If the remaining modules were spread out so that the time between the optical sensing and the creation of the magnetic field was offset, you could theoretically get quite near the speed of sound.

@electronoobs. It would be nice to make a v2 of this chrono taking into consideration some of the feedback. Of note mainly the following: Sensor response times (replace LDRs), Arduino input lag too high(choose alternate device), possibly a different arrangement of sensors and emitters. Thank you. Great project.

What 3D printer do you recommend?

It's amazing But I would suggest using direct registers for timer And also to try using input capture mode

Hi !nice work. Working air rifle?

Could you please design a lte signal booster. They cost a lot of money and I was wondering how cost effective it could be to just build one yourself. There are a lot of fake diy signal booster videos on RU-vid but if you made one then I'll know it's legit

very cool, but 120 mt/s sound a little bit unrealistic.. did u compare it against a "Proven" chronograph?

I tried this project but The screen is not setting to zero

Nice algorithm bro…but it would have been great if you actually tested a bullet firing to get the bullet speed….testing a product with universal accepted values would have been wonderful project….anyways impressed with your algo…subscribing for your future alogs 👍👍👍👍

Would have been interesting if you would calculate the kinetic energy of the bullet! Speed is already given... :)

What about making a chamber pressure tester? You glue them to a gun barrel and from how much it flexes you can tell how high the pressure was. I am wanting to make a modern gun. Perhaps a portable hypervelocity gun. I really need someone good at electronics and ideally crazy projects. Let me know if you ever get interested.

An ingenious project that I would like to recreate. However, with a difference, instead of the 8 digit display MAX7219 the 4 digit display TM 1637 should be used. Now I'm an absolute sucker at programming, I can change a code to make it work but write it myself........ I despair of that. Can you help me change the code so that the TM 1637 works? Greetings from Germany Thomas

What is the mass of your projectiles?

Cool project as always. I am a bit surprised at your decision to use LDR's instead of photodiodes since LDR's are known to be slow responding. However, it seems to work OK in your case and for the speeds your interested in. It would be interesting to build another one that uses photodiodes. It would also be interesting to calibrate this device with a spinning disk at a known RPM.

I think if u use a glass rod in front of a laser the beam will become a 'plane' ig. The dot will turn into a line

👍👍

A project like that, which will propably not be used very much would be better with a few AAA Batteries in series, since a liion will just be wasted when its sitting on the shelf.

Can you please make driver drowsiness detection system using raspberry pi and usb camera

so, I'm still waiting for the second VFD video you said you'd make

Why wire the LDR's in series instead of in parallel.

LDRs are too slow. They need time to react to the change of light intensity. Maybe it's ok for the coil gun but for a real bullet maybe not. The bullet stays in front of the sensor for a very short time. Concerning the mirrors you should just use shinny metal, not ordinary glass mirrors. The glass absorbs too much light and also creates ghost reflexions.

👍

3:15 - Needs first surface mirrors

Why didn't you show how the railgun fires from 10 modules?

👍.

Not bad 310 mph my air rifle only shoots 400 mph ! Well done

Интересный проект!Однако, фоторезисторы, применяемые в качестве датчика, являются инерционным радиоэлементом. Я бы предложил вам заменить их на фототранзисторы.

I like this Project and you did an amazing job, but maybe there is room for tuning it to get a better accuracy. Maybe you can do a V2 with some interesting Topics ;)

2:36 Not shell/round but bullet!

We fire the whole bullet, not just the tip, producing 64% more bullet per bullet.

🌟🌟🌟🌟🌟

And then finding its kinetic energy☠️

LOL, your animation of the "bullet"...

alot of power being consumed in recoil

I think your velocity reading is WAY off. You’re saying that this coilgun is shooting with roughly 170J of projectile energy (based on projectile dimensions in previous video resulting in 17.5g of steel). The capacitors hold about 344J of energy, meaning that your gun is resulting in just under 50% efficiency. Given that coilguns in a lab environment cap out at around 3-4% efficiency, something seems wrong here. Especially considering you have no adjustability to your timing on your gun and LDRs are extremely slow.

Use doppler

0:30 “it is a very easy project” Proceeds to show circuit boards and confusing sh*t

Like🧡🧡🧡🧡🧡🧡🧡🧡🧡🧡🧡🧡🧡🧡

La pobre pared :(

This is a speed test ru-vid.com/video/%D0%B2%D0%B8%D0%B4%D0%B5%D0%BE-vfXLnKsya4s.htmlsi=bjGYsJhmOanxKwlh

warning: money makes stupid, for real