"In the world of spuds today"

ramses · Sun May 15, 2011 1:53 pm

Alright, the 4" cannon works, but no longer uses a toolie valve. It now uses a 3" sch 40 PVC endcap, 2.5 layers of plywood, and a steel plate. Weight is unknown, since my deadline was today.

I works, but a little too well

. Suffice to say that my robotics team will be replacing two tempered glass doors that sit about 300 feet down the hallway from the robotics room.

There will be more (along with pictures) in another thread.

Crna Legija · Tue May 17, 2011 9:15 am

ITWOST, opening a 1/2full LPG tank to let the gas out, in your back yard is a REALLY bad idea.

My dad found a cars LPG tank on the road he picked it up took it home and opened the valve let it vent for a bad 6-7 hrs. I didn't know until 10:30AM i hear a massive BURRRRRRRR and see a red glow from the back of the house. Rush out side to see the hole back yard on fire and the flame slow heading towards the tank, bolted to the hose and started to water everything that was burning.

I think our hot water systems pilot light set it off, luckily no one was hurt and nothing was burned badly. We told the one neighbor that isn't related to us in the street we forgot to turn off the bbq gas tank.

Good news the tank is now only 1/5 full

Lockednloaded · Tue May 17, 2011 7:34 pm

ITWOST, propane tanks are pretty tough, but I'll crank it up to 700 psi before I admit defeat

al-xg · Thu May 19, 2011 3:05 pm

Has this been posted yet ?
http://www.velocitip.com/index.htm

Stupidly expensive and may not cope with high velocities but interesting idea !

Labtecpower · Fri May 20, 2011 7:23 am

Spare parts projectile.

Weight: 475 grams.

Will be shot this afternoon. Video is coming !

jackssmirkingrevenge · Fri May 20, 2011 7:31 am

al-xg wrote:Stupidly expensive and may not cope with high velocities but interesting idea !

How much are we talking? Doesn't sound like something I would be happy to load into a spudgun barrel.

al-xg · Fri May 20, 2011 7:56 am

Some guy on an archery forum apparently asked for a quote: 1100$ for tip, dock, and PC software...

The highest velocity I've seen mentioned is 300fps...

I saw labtecpower's pictures and though someone had already upsacled it !

Yamroll · Fri May 20, 2011 10:18 am

Ugh, the place next to my work has about 4 yards each of 10", 6", 4" and 2" PVC laying out in the sun behind their warehouse. Fittings and ball valves too. Shame

Labtecpower · Fri May 20, 2011 10:24 am

[youtube][/youtube]

The projectile went through 2 pieces of 3/4" MDF, and trough one sheet of 3/4" plywood.

Second shot is the same, but all the sheets are put directly against each other. The round was stopped by a 1 mm steel sheet.

Youtube says quality will get better after processing, but I will upload a better quality video. May take a while

Yamroll · Fri May 20, 2011 7:41 pm

Drat, the rubber washers I've been using as the sealing face on my new barrel sealer keep getting stressed out by air pressure and blowing out the barrel when I fire it hahahah.

Technician1002 · Fri May 20, 2011 9:03 pm

keep getting stressed out by air pressure and blowing out the barrel

You need to get serious about the size of the bolt and washer you hold it in place.

I had one that used to launch the o ring, but with a change in style, those problems are history.

Labtecpower · Sat May 21, 2011 10:21 am

Here is a better video of my QDV. first shot is a pingpongball at 6 bar. The previous one shattered inside the barrel.

The recoil with the custom projectiles is insane. I need about 2 people to hold the gun.

[youtube][/youtube]

Technician1002 · Sat May 21, 2011 12:11 pm

Nice job crushing pingpong balls in the barrel. I'm going to have to try that. The only thing I know I've crushed in the barrel is a foam sabot and a few eggs. I had a 2 inch sabot shrink enough to pass a golf ball in the barrel so the sabot came out first. It was then I realized foam under pressure compresses just like the air in it.

Labtecpower · Sat May 21, 2011 1:22 pm

The pingpong ball must have been weakened. The one in the vid was shot against the wall, and only had a hole in it.

The shot was deafening. That's why all my classmates are yelling. (yes, this was done at school )

Another projectile pic (after hitting the steel plate)

Somewhat less refined than the MiniBoy

Almost 10 times as heavy?

drex · Sat May 21, 2011 4:42 pm

I had a go at making an APFSDS round this week.
The tip (94g) is made of 17-4 steel, the body (61g)is made from polycarbonate, and the sabot is made out of nylon and is 28g.

"In the world of spuds today"

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