Full-Auto Crossbow Rocks and Rolls on Rubber Bands and Electric Drill

You’ve got to enjoy any project where the hacker clearly loves what he or she is doing. And when the project is as cool as a motor-driven, rubber band powered, fully automatic crossbow, it’s hard not to laugh along.

A full-auto crossbow is no mean feat, and it took a man with a love for rubber-powered firearms to get it right. [JoergSprave]’s design is based on a rack-and-pinion system and executed mainly in plywood. The main pinion gear is a composite of aluminum and wood, in a bid to increase the life of the mechanism and to properly deal with the forces involved. The pinion, turned by a powerful electric drill, drives the rack back and locks the carrier under the 30-bolt magazine. A rubber-powered follower forces a bolt down and a cam on the pinion trips the sear, the bolt is fired and the cycle continues.

We slowed the video down a bit and it looked to us like the cyclical rate of fire was about 7 rounds per second, or a respectable 420 rounds per minute. Pretty powerful, too, and the accuracy isn’t bad either.

We’ve seen [Joerg]’s inventions before, like this soda bottle Gatling arrow launcher, or his ridiculous machete launcher. We hope he keeps having fun and letting us watch.

[via r/videos]

26 thoughts on “Full-Auto Crossbow Rocks and Rolls on Rubber Bands and Electric Drill

  1. That is fun and cool, he has a great laugh an does enjoy his homemade toys.

    But what struck me as a Florida guy there is was in snow and he is out there in short sleeves!!!!

      1. Manitobans and Ontarians shouldn’t be teasing each other, we should stand united together ….

        …. and mock Vancouverites dealing with “OMG what is this white stuff.”

    1. But he seems not to be sweating. :-)
      Two weeks ago I was helping my father replacing a tarp on the (frozen) pool and although somewhat sunny, it was below zero (°C) So this PVC was really stiff (and heavy) and it didn’t take long to start sweating, just wearing a T-shirt.

  2. Nice… if you want to compare and contrast, search for duckman automatic crossbow.

    Possibly you could use a pinion wheel from a hand drill to put a motor to the rear of it. Like an automotive sliding door motor.

    I think in concept it would be legal in Canada, but you might need a non-removable stock on it, since “pistol” crossbows are verboten, but it also defines a minimum length. Then although “firearm” is explicitly defined in firearm act, there’s other regs that include BB guns and crossbows as a “firearm”, so you look up your most local regs and see a bylaw against discharging firearm in city limits, and you’re left wondering if it’s the prime definition, or the extended definition, and you can shoot any crossbow in your backyard or not.

    But anyway, off to Harbor freight to buy 9HP diesel, trailer leaf spring, and a few dozen lengths of rebar…….. (kidding)

  3. Yes are expecting the zombies to make it up here as well.
    But we as canadians have some secret weapons that we are not allowed to talk about.
    Top secret and that. AH
    And people fleeing from trump apocalips.

  4. Jörg Sprave is an amazing guy, He always had a passion for slingshots. He used to have his own buisness but gave it all up to make youtube video’s on his passion for slingshots. almost every video he creates a new exciting slingshot from parts you can find at your local hardware store.
    He is one of my favourite youtuber’s I have been watching him for years and haven’t got bored of him once. Normally I get bored of a youtuber after a few months but he has this atmosphere about him like the loveable uncle you never had *sniff*. He makes all his gears, rachets etc from wood. and has even built what he called an “airzooka” If you haven’t seen that video you need to do it now.

Leave a Reply

Fill in your details below or click an icon to log in:

WordPress.com Logo

You are commenting using your WordPress.com account. Log Out / Change )

Twitter picture

You are commenting using your Twitter account. Log Out / Change )

Facebook photo

You are commenting using your Facebook account. Log Out / Change )

Google+ photo

You are commenting using your Google+ account. Log Out / Change )

Connecting to %s