I tested this and found PVC is brittle and the shallow sockets for DWV tend to crack loose, break, or fail in interesting ways, even after passing initial testing. My Mouse Musket was a study of the impact resistance of PVC. If it takes a beating, it will break. I looked at the soda pop bottles and ...

The rule of thumb for piston travel is that it should travel about 1/4 the length of the valve port. If you're shooting golf balls, about 1.6", your piston only has to travel about 0.4" to achieve maximum flow. I'd let it travel about half an inch personally. This rule is based on the area inside t...

Since I typicaly get only one shot per ball, definately used. Free preferable.

Golf balls are quickly lost into the sky when fired from this type cannon. I even tried launching them into a lake and lost sight of it still climbing and didn't see it land in the lake. They just go into the sky, shrink in size and vanish.

I've seen only one major detail left out of the above posts. The surfaces that come together to seal, must come together completely. Any surface uneveness will leave a relatively large leaky gap. The first order of business is to polish and true the valve seat. A wooden dowel the same diameter as th...

Basically what happens is that the pilot area of the valve is dumped, but refills quickly, hence the "honking" - modifying the valve for pneumatic actuation should do the trick. In many cases this is almost correct. The real reason for honking in unmodified valves is the rate the pressure drops in ...

A laser sight on a marshmallow gun is a total waste of time. Trust me on that one. The aerodynamics of a marshmallow in flight leaves a lot to be desired. Odds of hitting a gallon milk jug at 30 feet is about nil.

Sorry for the late reply, but I've been out a few days. Brass and a brazing rod melt at the same temp if they are the same composition. Joining metals with more of the same metal is called welding. Using a lower temperature metal to join two similar or different metals is called soldering at lower t...

If the carbide cannon has a chamber fan, the burn rate is fast enough that a burst disk is not needed. A burst disk is of benifit on slower burning fuels. If you search the vortex cannon video online you can see the burn rate is fast enough to not need a disk. I would not want to be holding a carbid...

If it is combustion don't use steel wool.

Before threading carbon steel rods, be aware it can be a very hard steel and may end up reaming out your threading die instead. Threading tools are for mild steel only such as maluable iron pipe. To thread high carbon steel, it will either need annealed changing its strength, or cut with a die grind...

The scariest words in the English language... I have an idea!

Never heard "Hold my beer and watch this.."

Due to the pull resistance at higher pressure on a QDV due to seating of the o rings, unless you use a sizable slide hammer to knock it open, I do not recommend an un piloted QDV in a 4 inch size. You might not be able to pull it at pressure. I have on the other hand toyed with piloting a larger QDV...

One of the problems you may run into with a digital gauge is the same thing you run into with digital bathroom scales. Sample and settling time. A combustion cannon will have the same measurement issue you will have trying the measure the impact force of a basket ball on a digital bathroom scale. I ...

The gas sensor used to detect Carbon Monoxide, Natural Gas, etc are generally based on the same semiconductor sensor. If you get the datasheet, you may be able to disassemble a Carbon Monoxide or natural gas sensor and interface it with an arduino, then with testing calibrate the resulting combinati...