That's probably even good underwater. Awesome build, well done! If you're at 6 shots, you probably are around 60 or more joules. Anything above 44joules is good for self defense at 10 yards.
I don't think that can be even 10 joules. Those little 80 ft lb pistol crossbows travelling at 56 M/s with a 7 gram bolt produce 20 joules on a good day and when you up the bolts to the weight of these ones, probably around 12 grams or more that energy will reduce further. But they still manage to pass straight through water melon and penetrate the backstop every shot.
@@noncompliance4100 NOPE. Do the math with me and let's check this out... He is recording with a Huawei P40 Pro at, *supposedly* , 7680 FPS. The cans have a diameter of about 6.58 cm (data found online). If you watch frame by frame, the arrow takes 5 to 6 *frames* to penetrate a can (like the "fanta" in the video). So, divide TOTAL FPS by "6fps",take the result, multiply by 6.58cm and divide by 100 to know the meters per second... [ (7680 / 6) * 6.58 ] /100 = 84.2 m/s. Now, a standard arrow is 30 inches and weighs about 36 grams. The arrow in the video takes approximately 27 frames to penetrate the can, so, if it takes 6 frames for 6,58 cm, the arrow length should be (27/6)*6,58=29.6cm. 30 inches are equal to 76cm. So, 76 divided by 29.6 = 2.5 pieces, meaning that the small arrow weighs 36grams divid by 2.5 = 14.4 grams. Now, 14.4 grams at 84 meters per second are more or less *50 joules* ... And that's all about it. Unless he recorded the video at 960fps. In that case, it's less than one joule (0.76 joules) but it's impossible to penetrate 3 coke cans filled with water at less than one joule of power, at 10.5 meters per second (which is what the math would say at 960fps). Change my mind. P.s. : my numbers were bigger actually. I've used 5 FPS on paper, not 6. Arrow 34cm and 16 grams of weight at 101 meters per second.
Hi, I made nearly the same construction...but I was not really satisfied: yes,, the power of the first shots were good like yours. But you loose a lot of power by the volume of the valve, next I connected the shellholder straight to the gun: more power but the trigger got more "hard" - I guess that the o-rings of the valve gets hard by the cold. About the tuberail: you should inform yourself about the problem called cavitation, it is a problem well known in hydraulic and pneumatic engineering.That is why I made test about the lengh of that tubes, I checked several blow pistols on the market and I constructed several ways to improov the power...the speed....and the way to supply the pressure...and I added a weaver rail with a sight and a laser. Well, a good solution to have a silent and very strong way to be prepared....
Possibly copper infused thermoplastic o-rings to maybe withstand the cold. I like your insight. Cause I was about to build this for myself but now I'm going to take to back of my brain for more research and development.
I never thought of the decrease of power by volume. No offense to the person who posted this video. It's a brilliant idea but as with all science and technology. There will always be obstacles to overcome. I worked with thermoplastics in the past and I know certain formulas can withstand high heat temperatures so maybe with a alterations and choosing different materials to melt with raw carbon and also obviously some sort of extremely durable rubber material (possibly silicone) that won't be destroyed by the carbon when they are both heated and compounded together. You can probably just buy something like that but I think making it is more fun.
@@michaelbanville8029 Hi, meanwhile I tested it - badly: the cheap airblowers have only small airchannels, and the valve is blocking by too much pressure. They are shure up to 20bar press - but this means only by security without break or exploding. I tried a cheap one - here the valve opened...but was not able to close again, the whole pressure was gone, no second shot possible. The springs of the valves are too weak, and sometimes the o-ring of the valve stayed not in position but were found inside the valve blocking. My idea: better take a paintball-gun...and construct a inside barrel which is inside the original one: less diametres will encrease the pressure and better fitting arrows will work better than heavy rubberballs....and are working with tips. And those guns are able to handle pressure of 300bar air - not CO2 which will get fluid. And this is the problem: if getting gas again on decompression the gas is freezing the barrels. BUT here in Germany painballguns are declared to be weapons and are F-signed..means if you make changes you are are producing illegal weapons....but if you are using "airtools" it is only an unauthorized use - you are not breaking the weapons laws. Well, it is no way to put Physics upsidedown if you know what I mean. There are better possibilities to think over.
@@thomas-eckhardscholz1448 Well said and explained. It's always a small thing that has such a huge impact on the project at hand. I like the paint-ball gun idea. I'm not sure about the laws where I live but with things like this I'll surmise if I may, that most of those who take on projects like this are thinking about a s.h.t.f. situation in our immediate environment and not with the intention to harm someone. Anything can be considered a concieled weapon if it is not out in the open and even still if it is. I'm not an engineer by trade but I have some knowledge and experience in the field. I enjoy building and creating obviously with safety being put first.
MAKE OFFICE AIRBOW WITH COFFEE STIR STRAW, TOOTHPICK, CELLOPHANE TAPE FOR FLETCHING AND TO FATTEN TOOTH PICK TO LODGE FIRMLY IN END OF STRAW; USE CANNED AIR FROM KEYBOARD AIRDUSTER. FIGURE IT OUT - SHOOTS 50 FEET.
You can find most of even all of these parts at home Depot or harbor freight. I took screenshots of everything one by one and found everything in those two stores I mentioned.
Why not just tap and thread a hole in the elbow for the pressure gauge instead of waisting time on that bulky aluminum piece. Also if you used a small air compressor like the one's you plug into the cigarette lighter of a car and a small 12v battery with a small air line all in say a backpack then you wouldn't have to replace co2 cartridges. Any who it's still kool and I appreciate you making the video.
A CO2 adapter with a pressure gauge would be the best bet instead of having to drill any extra holes. As for the 12v pump, those only got up to around 160psi which is much less than the 800psi in a CO2 cartridge. You would need a much larger tank air tank to have the same effect.
Maybe using an old paintball gun for parts. They used to sell another type of gas to run them that was better than co2 but I can't remember what kind it was. I like building potato guns more because all you need is pvc, hairspray, and a bbq lighter.
