Functional LARP Balista

This project was made to throw variety of foam projectiles. The most effective one seems to be stone (which is really little sandbag wrapped in foam and powertape.

Supplies

• Spruce 2x2

• Spruce 2x3

• Spruce 2x4

• Oak wood

• 5mm metal strips
• Veg tanned leather
• Rope (for drawstring and skein)

Step 1: Wood Preparation

We carefully measured, sanded and planed all the wood we had. After that we measured it again and cut it to lenghts we comletely made up.

Step 2: Frame

Balista's frame consists of two types of parts.

• Head piece, (on the top and bottom) two needed
• Support piece, four needed

They are joined with mortise and tenons, which are not needed to glue up, because they will be holded by force of the skein (the rope spring).

Step 3: Head Piece

Head piece has four square mortise holes and two round holes for the rope. All the square mortise holes were drilled first, then cutted out with jigsaw and finished with chisel.

Rope holes were only drilled and rounded with a router.

Step 4: Support Piece

We clamped all the support blocks into our workbench and cut sides with circular saw (with depth set). This way, all the tenons were made at once. Finishing was made with chisel, again.

Step 5: Test Fit

After cutting, some test fits with some adjustments were made.

Step 6: Balista Body

The part, on which projectile slides on. We cut one board at an angle and glued these two parts at the edges of another one, this made groove for projectile to stay on track. To improve strength and spare us waiting for glue to dry, we drove some scews from the other side.

Step 7: Ratchet Mechanism

For loading the whole thing. Gear is made out of oak wood, pawl is bent metal strip. Gear is mounted to wooden (oak) shaft, which by rotation winds up leather strip, that serves as a drawstring.

Step 8: Ratchet Gear

Made out of two perpendiculary glued slabs (PVA glue). Drawn shape of gear was first drilled, then jigsawed and finaly rounded with router. Square center hole was made in similar fashion and finished with rasp.

Step 9: Ratchet Gear Shaft

Made on lathe, shaped to form three thick sections and two narrow sections. Narrow sections are to fit into mechanism base.

One end was cut with jigsaw to fit the gear.

Step 10: Finished Ratchet

Pawl is just a piece of thick metal strip, which was bent and screwed onto mechanism box. Wooden shaft has hole in the center, which was later used for woodscrew with big washer, that holds gear on the shaft.

Step 11: Slider

There is this part, thats slids on the body part of balista and hooks drawstring. Partly made out of hardwood and bent sheet metal. Every sharp corner and stickout screws were grinded out with angle grinder.

Step 12: Assembly

Everything was put together. Metal trigger was wedged with wooden block, taking it out, makes balista shoot. Frame was fastened to body with screws.

Strands of rope were pushed through head piece's circular holes. Metal bar was put through the strands at the top and the bottom of the frame. Bars were rotated to acumulate spring force and secured with thick leather belts.

First shoot tests were fired! :-)

Assebled balista was then equipped with perpendicular block of wood with stickout metal rod (this was in fact part for wooden constructions bought in hardware store, grinded round and tapped). Metal rod will serve as mount for stand.

Step 13: Stand

Made out of two 2x3, perpendicular to each other, creating T shape. Square hole was drilled to the longer end and nut was trapped inside.

Step 14: Stand Wheels

Tongue and groove were routed into wooden planks to form a board. Again, they were glued together with PVA glue.

With our jigsaw clamped to workbench and board clamped near the tip of the jigsaw blade to guide the blade, we were able to put together circle cutting jig (inspired by Matthias Wandel of course).

We put some metal bracing on, to make it stronger and look more Warcraft like :D.

Wheels were fastened to same component that stick out of balista's body.

Step 15: Finished

Now that we have this, we do not fear dragons or any other enemies. No need to tell many terrifying opponents were slaughtered by this new technology of ours!

Cheers!

Kudlas