A few months ago, I had to help a cousin of mine with a college homework about the physics of parabolic trajectory. He's really good at math, but very bad at crafting. It was my turn to save the day!!

I had only one night to build a machine capable of launching an anti-stress ball, with adjustable height. So, I combined a plastic beer jar (marketing stuff from a colombian beer named "Costeña"), a toilet tree for the elevation and other stuff for the frame. It works with two spings, like some type of slingshot. You charge the mortar, lock the trigger, push the trigger and it launch the ball.


By building this Spring-Action Mortar, students will be able to build a educational project reusing stuff and analize the physics of launching a projectile with parabolic trajectory.

Step 1: Materials and Stuff

You will need the following materials:

  • Acrylic beer jar
  • Sheet made of acrylic or another hard plastic.
  • Electric shower case, that fits in the jar mouth.
  • Two springs (for the "slingshot")
  • One smaller spring (for the trigger)
  • One PC screen base
  • Two printer pieces (for the mortar mount)
  • Toilet plastic floater graduating piece (tree)
  • Hinge
  • Metallic angles
  • parfum round cap
  • bolts and screws
  • Two key chain rings
  • round telephone cover
  • vents (for fixing the mortar to the ground)
  • vaseline
  • anti stress balls
  • Dremel
  • Screwdivers
  • Pliers
  • Tweezers

And remember:

1. If you don't have it, replace it!
2. Use protective equipment (dust mask and goggles)
3. Beware of drilled and soldered hot surfaces
4. Work in a good ventilated area.
5. Always have junk in stock
6. Enjoy!

I built something similar to this with a ton of rubber bands and those plastic planters that you buy plants in. It didn't work too well, but shooting legos at people was always great fun.
Nice work! <br>Did you realize you have here the makings of a Dog's Toy Ball thrower? <br>I mean, you can set the thing to throw the ball REAL far away, so the pooch can exercise to it's heart content, without you being bored or tired...
WOW!!! IT'S AN AMAZING IDEA!!! Thanks!! :-)
Nice job . I liked all the pictures you had . I also liked that you made it from stuff just laying around and didn't need any expensive tools to work on it .
Thanks Randomray!! :-)

About This Instructable




Bio: I'm Mario Caicedo Langer, from Colombia, former Navy officer and BSc in Naval Sciences. Right now I'm Technical Director and Technology Lead Teacher ... More »
More by M.C. Langer:Roboto, the Wobbling Toy Robot (evolution of Randofo's "Wobbler") Cheap and easy catapult for Hot Wheels style toy cars Creepy Mechanical Baby (made From Broken Toys) 
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