|
Schultz Engineering, LLC 2011 Desktop Trebuchet Design |
|
TREBUCHET - A Medieval Weapon of Mass Destruction Childs Toy in March 2011 - Notice this trebuchet is made of scrap wood (Brazilian Red Wood decking scraps) and has sand in a plastic bag for it's counterweight. Cost: Almost nothing, not counting the time it took to scrounge for materials.  |
|
Basic Drawing - March 2011 Basic Drawing. If holes are precision drilled for location, everything will assemble fine, but experience has shown that it's best to drill the hole in the vertical stick where the triangles meet during assembly.  |
|
Completed Trebuchet and Materials Here is a completed trebuchet and the materials needed to build one. A Bill of Materials shopping list is presented below for details. Menards is a great, one stop shopping location, they have great prices and also have lumber. By the way, those are paint sticks. The base is a 1 foot-long piece of composite decking.  |
|
Materials The small water bottle is filled with 1 pound of steel shot from a local factory (scrap from a punch press). Other materials that might work would be sand, or shot for reloading shot gun shells, or fishing weights. The bearing shown in the picture is a nice touch, but can be replaced with a stack of 6-8 washers that provide a sufficient bearing surface on the threaded rod. The pouch and string should be of very soft and supple material. For instance, velore fabric and yarn for string.  |
|
Brad Point Drill Bits Use Brad Point drill bits to help avoid spitting the paint sticks when drilling holes in them.  |
|
Proper String Length String length is best if the pouch is at the centerline of the throwing arm axis.  |
|
Closeup There is a lot of detail shown in this picture. The bearing system, the use of nylock nuts, the suspension of the counterweight using an eyebolt, etc.  |
|
Strings Holding Pounch The string tied to the key is tied to two corners of the pouch. The other string is tied to the center of the other end of the pouch. The string hanging down in this picture, has a loop tied on the end that can easily slip off the key release pin.  |
|
Ready to Release This release position gives the maximum distance.  |
|
Trigger Release 1 Our trebuchets have an adjustable release pin. The angle of the release pin affects the trajectory of the projectile. Also, the mass of the projectile affects its trajectory. Assuming a clockwise rotation of the throwing arm in this picture, the release mechanism tilted CCW will cause the projectile to have more height.  |
|
Trigger Release 2 Assuming a clockwise rotation of the throwing arm in this picture, the release mechanism straight up will cause the projectile to have a flatter trajetory.  |
|
Trigger Release 3 Assuming a clockwise rotation of the throwing arm in this picture, the release mechanism tilted CW will cause the projectile to be thrown into the ground.  |
|
Bill of Materials Shopping list and basic cost for building your Trebuchet  |
|
Dimensions for Sling Obsolete build notes from previous year build. You'll find dimensions for the pouch on this picture  |
|
Other less expensive bearing systems Use a nut or a stack of washers for the bearing that rotates about the threaded shaft  |
|
Inventing a better tomorrow today... Copyright 2010-2011, Schultz Engineering, LLC |