You really shouldn't use that above 60psi because you have a DWV reducer and a DWV cleanout cap on it. Pressure rated pipe doesn't really help if your fittings aren't pressure rated. It may have survived so far, but that doesn't mean it won't blow up on the next shot. It is completely legal in the US.
This run was at 125psi because that is the max the compressor we used could put out. The outer 4in is rated to 220psi, but the endcap threads would leak too much to reach that.
Are you using thread sealer/lubricant cream on the caps or just putting them in? Be careful if your using dwv parts on that they dont slide in as far as schedule 40, I've had a cannon explode into two separate pieces in my hand, scared the crap out of me... I'm currently working on a piston coaxial mini cannon with a 4" outter and 2" barrel. I'm probably going to also make an internal chrono with an AVR and possibly a tilt sensor to calculate the range and such. Have you tried using helium?
We use teflon paste on the end cap, but it still leaks above 110psi, so you need a high volume output compressor if you want to get to higher pressures. Everything is schedule 40 pvc. The velocimeter at the end of the cannon in the movie was built with LEDs instead of lasers. As such, it worked in testing, but not at production speeds. I have not tried helium in it; we work on the cheap.
Not really sure about max velocity. The apparatus on the end of the barrel is a velocimeter, but it was calibrated too tightly to catch the potato passing. I would need to have used lasers instead of LEDs in the line break. The max range shot was 394yds.
that cannon makes a funny ass noise...better than my cannon when the valve doesn't open all the way :)
squirrelgecko 3 years ago
thats crazy man!
jackhorrocks 4 years ago
You really shouldn't use that above 60psi because you have a DWV reducer and a DWV cleanout cap on it. Pressure rated pipe doesn't really help if your fittings aren't pressure rated. It may have survived so far, but that doesn't mean it won't blow up on the next shot. It is completely legal in the US.
dumbpeopleRlucky 4 years ago
whats the peak pressure you got that up to? looks like you have a DWV reducer on there...
SlavaVB 5 years ago
This run was at 125psi because that is the max the compressor we used could put out. The outer 4in is rated to 220psi, but the endcap threads would leak too much to reach that.
fractalcollins 5 years ago
Are you using thread sealer/lubricant cream on the caps or just putting them in? Be careful if your using dwv parts on that they dont slide in as far as schedule 40, I've had a cannon explode into two separate pieces in my hand, scared the crap out of me... I'm currently working on a piston coaxial mini cannon with a 4" outter and 2" barrel. I'm probably going to also make an internal chrono with an AVR and possibly a tilt sensor to calculate the range and such. Have you tried using helium?
SlavaVB 5 years ago
We use teflon paste on the end cap, but it still leaks above 110psi, so you need a high volume output compressor if you want to get to higher pressures. Everything is schedule 40 pvc. The velocimeter at the end of the cannon in the movie was built with LEDs instead of lasers. As such, it worked in testing, but not at production speeds. I have not tried helium in it; we work on the cheap.
fractalcollins 4 years ago
how fast did you max out a potato on that?
SlavaVB 5 years ago
Not really sure about max velocity. The apparatus on the end of the barrel is a velocimeter, but it was calibrated too tightly to catch the potato passing. I would need to have used lasers instead of LEDs in the line break. The max range shot was 394yds.
fractalcollins 5 years ago
you should try a rifled barrel they work great
andrew5607 4 years ago
Thats a sweet sound when it fires
SlavaVB 5 years ago
yes it is
andrew5607 5 years ago
potatos arnt fruit idiots
andrew5607 5 years ago
The Crystal Method - Starting Over
Rise Against - Dancing for Rain
fractalcollins 5 years ago