SpudFiles

Hey guys. I have recently constructed a tennis ball mortar out of 3" diameter PVC pipe with two pringles cans lining the inside to act as baffles as detailed in the tennis ball mortar plans of the book "Backyard Ballistics". I use lighter fluid as my propellant an a piezoelectric lighter or long handled fireplace matches as my ignition source. Unfortunately, I have failed to get the tennis ball to fly out of the barrel. I know I am achieving ignition as I here a "whoosh" sound when I ignite the lighter. I also know I have achieved combustion as the tennis ball has a ring of carbon deposit when I remove it from the barrel to try again. What am I doing wrong? Any help/input would be appreciated. Thanks, you guys.

Too much fuel. Reduce it to go from whoosh or whump to bang.

Xenophile wrote:with two pringles cans lining the inside to act as baffles

Baffles? In a combustion chamber? Doesn't make sense to me...

If you want turbulence to encourage complete combustion, use a fan.

jackssmirkingrevenge wrote:

Xenophile wrote:with two pringles cans lining the inside to act as baffles

Baffles? In a combustion chamber? Doesn't make sense to me...

If you want turbulence to encourage complete combustion, use a fan.

The baffles are to hold the tennis ball and prevent if from dropping all the way to the bottom

battlelava wrote:The baffles are to hold the tennis ball and prevent if from dropping all the way to the bottom

One simple screw will do that without filling the chamber with rubbish

jackssmirkingrevenge wrote:

battlelava wrote:The baffles are to hold the tennis ball and prevent if from dropping all the way to the bottom

One simple screw will do that without filling the chamber with rubbish

Yea I wish I could find my copy of the book so I could post what its suppose to look like