Today (Friday 7/12/2013) my friends and I had a chance to do some test firing! With the 4 foot barrels we consistantly got 198-210 yards (600 ft) with potatoes. Then we put a little bit more hair spray in the chamber and we got 200-250 yards. The longest was with a 2.5" barrel (48") and a longer sho...

Today (Friday 7/12/2013) my friends and I had a chance to do some test firing! With the 4 foot barrels we consistantly got 198-210 yards (600 ft) with potatoes. Then we put a little bit more hair spray in the chamber and we got 200-250 yards. The longest was with a 2.5" barrel (48") and a longer sho...

In that series of posts, a link to test that "Insomniac" did with a clear soda bottle shows the flame propagation of actually moving the igniter. He did say, It's important to note that not all the varience in flames was caused by spark location, as the mixture was varying significantly from shot-to...

Thanks for the link. They changed the chamber volume by altering the position of the tennis ball, to show the effect of having ignition at the rear, centre and front of the chamber. The igniter was in the same position, but the tennis ball was moved. The author said, the "rear" ignition appeared mor...

Has there been testing on the best location for a plain hair spray combustion spud cannon? Let's stay simple and a straight combustion chamber inline with the barrel. Should the spark be closer to the potato or the back end (capped)? My first build has a 4" combustion chamber with 17" cut length of ...

... for instance if i have a 2'' barrel that is 60 inches long the volume is 753.6. if i have a 4'' chamber that is 24 inches long i have a volume of 1205.76. When you do the ratio, the units of measure don't matter (cancel out). But FWIW, this is what I calculate: (2.00"/2)^2 * Pi * 60" = 188.5 cu...

I just joined this forum and look forward to searching/reading/posting. This weekend I made my first Spud Cannon and the test fire went great. 4" dia combustion chamber, 19" long effective (17" pipe cut length) 2" dia barrels, screw-on, 49" long and 73" long Hair spray propellent (AquaNet) BBQ piezo...