Build-it-Yourself Air Cannon Plans

LS LongShot Potato Cannon Plans

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For Accurate firing of Projectiles

LS LongShot Air Cannon Plans

How to Build the LS Long Shot
Spud Gun Potato Air Cannon

Here are some general instructions on how you can make a potato cannon. This cannon will fire potato slugs at around 150 miles per hour, for hundreds of feet.

A potato cannon is capable of causing serious injury either with an impact of the potato or with an explosion of the cannon itself. Use these instructions at your own risk!

First: Gather Materials, Schedule 40 PVC

  1. 1 1/2" diameter PVC barrel (around 5 feet plus or minus)
  2. 1-1/2" Barrel to 4" chamber PVC reducer
  3. 4" diameter PVC chamber - around 18" long +-
  4. 4" threaded cleanout adapter for 4" chamber
  5. 4" threaded cleanout plug for chamber end cap
  6. saddle tee (rides on top of chamber with no penetration)
  7. 1-1/2" PVC for grip - 12" long +-
  8. 1-1/2"end cap for grip
  9. gas grill sparker
  10. heavy gauge wire
  11. 2 1/4 x 20 x 3" bolts and six nuts
  12. wire nuts for connecting wires if needed
  13. PVC cement
  14. spray solvent, or hair spray, for ignitable propellant

Second: Assemble the Potato Cannon:

  1. cut and cement together all the PVC parts as shown.
  2. note: the grip assembly should only require cement between the saddle and the grip tube, not to the chamber or the grip end cap.
  3. drill holes for the gas grill sparker, sparker bolts, and sparker wire escapes.
  4. wire the sparker to the sparker bolts through the grip and sparker wire escape holes.
  5. note: keep the wires away from each other as they could short out before the spark bolts and not cause a spark in the chamber.
  6. note: keep the wires away from where the operator's arms and legs will be. if the wires come into contact with skin, they will give off a shock, even through insulation.
  7. file the inside of the end of the barrel to cut and reduce the potato slugs when loading.
  8. wait sufficient time for the cement to dry.

Third: Time to Fire the Potato Cannon:

  • Remove the breach cleanout to allow air to escape from the chamber when you ram the potato in the muzzle.
  • Ram the potato into the muzzle using a blunt ram rod (a broomstic with a spool nailed to the end will work).
    • note: leave potato at least a couple inches shy of the chamber.
  • spray propellant into the breach.
    • note: you don't need very much at all (psht).
  • screw the breach cleanout back on.
  • make sure all friendly personnel are clear of the line of fire.
  • depress the firing sparker button.
  • lather, rinse, repeat.