Airsoft / BB CROSSBOW (powerful :)

Ahoihoi

Not as detailed as usual, but this time I had to figure out how, then make the thing, and then show the details

and parts. Its not a step-by-step, but the skilled selfmaker will know how to copy it :) and the skilled hobbiest

will even manage to get it done in a more simple way...and here we go:

Tools:

- Dremel Tool (drill bits and cutting wheel)

- Drillpress or stronger electric drill for the bigger holes in the wooden mag

- Soldering iron

- Pliers and wire cutter

- Screwdriver

- Working knife

Material:
- Aluminum U section, 35mm wide, for the base

- Alu U section for the cocking-sled, 40mm wide (or similar, they have to fit each other)

- Alu L section 10x10mm also for the sled

- Scrap sheet aluminum for the lock, 5-6mm thick

- 15mm wide and 0.8mm thick spring steel for the bow

- Steel string (solderable) 1mm

- Alu L section 30x30mm for the syring-mount and bow limbs mounts

- Alu square-bar 10x10mm on the syringe, gets caught in the lock

- Alu square pipe as a guide for the square-bar

- Plastic spacers 10mm or tubing (pillars for the square-pip guide)

- M3 screws and some M2 screws (smaller screws for mounting the covers

- Rectangular Alu pipes and U sections for the covers.

- 1 Plastic syringe 100-200mL

- Scrap wood (for the mag), 15mm thick plastic or metal will work as well

- Brass barrel (15-20cm long, 6mm outer diameter, 5.1mm ID)

- 5mm magnet to hold the BBs

- 5mm BBs

- Small tension spring for the lock/trigger

- Tiny o-rings

- M5 screw

Cut off 2 L-section pieces from the 30mm Alu L, 60mm long. Cut 2 pieces with the cutting wheel, about 110mm long, and another 2, but only 70-80mm long.

2 holes, 4mm diameter each as shown, mark the holes on the 2 L sections. Attach 2 on each L. Tiny hole for the string (measure 90-100mm from bottom) only 1mm.

Mount them on your U-section base. Then solder the string in.

Fabricate a syring mount from 30mm L section. Place it as shown on the U-base. Give the bow a bit of tension, then mark the spot and srew it on. 4 holes in the pistons rear part, 4 spacers and a baseplate.

Drill a hole right in the center or the baseplate, 3-4mm. Cut 95mm of Alu square bar. cut out a catch as shown,

M3 or better M4 thread into the other side. Then mount the bar on the plate. I drilled 7mm holes to make it lighter, thats up to you. Lighter means more power though :>

Cut a 45mm long piece of square-pipe, drill 2 holes to mount it and attach as shown. Make sure it lines up well with the syringe-piston and follows its direction, or it will jam or sit too tight.

Cut out the parts (templates above) and put them together as shown. Attach the plate in line with the square-bar's catch. I used 2 thin plastic spacers between lock-parts and their baseplate, to minimize friction. You also want to glue the mouting screws with some locktite or a drop of clearcoat, nailpolish or whatever you got. The 2 parts have to move freely and smoothly, but without coming off sooner or later ;)

Fabricate a mag as shown, wood or whatever you got available, Alu would be even better. Drill holes as shown, fabricate a cover-plate. M5 screw plus o-ring, M3 screw on the other side, and we are almost done.

For the covers and body, you are free to to whatever you want. A simple grip will do, if you want to go fancy, try it out and make your own design :)
The video will hopefully help you to get it done, its really not a starter-project, but fun!