Sneak preview: Forearm mounted crossbow

In about two weeks, German TV will come visiting. They want to include me in a show "People with crazy hobbies". Great coverage!

Of course they want something special that I haven't shown in an earlier video. So I pulled out my list of potential projects and settled for the concealable forearm mounted crossbow.

Of course I used rubber as the propellant, simply because a normal prod would be way to wide, never concealable. But of course the length of a forearm mounted weapon is short, I needed a draw increase so that the full power stroke is active. So rollers, again.

10 cm of rubber is stretched to the total span of 52 cm! Nice.

I wanted to make this mostly from wood. I even made a spring from plywood, so the bolt is held in place! Works like a charm. There is so little metal in the piece that I believe metal detectors would have a hard time finding it.

I wanted to be able to reload without dismounting the weapon, so I came up with a "fork". This little tool makes reloading quick and easy.

The trigger part is simply a length of paracord that runs underneath the string. If you pull on a knot by flipping your hand down, it shoots! Simple and effective.

I haven't started on the "beauty" task, and also I haven't maxed out the rubber. But it is really really fun to shoot with it, and it is fully concealable under my Army surplus coat.

Awesome! And good job getting more TV coverage!

WWOOooo

that's slick looking man, make sure you lube the crap outta those rollers. Use silicone or even graphite. If the rollers don't spin quickly you'll lose a lot o' speed.

I know you like your wood, but perhaps a nice leather bracer would be good for the cameras. It's just too bad though cause I think they'd have to kill a whole cow to get enough leather to cover your giant muscular gorilla arms.

You've finally built an arm mounted weapon, you are truly one of us now sir. Welcome to the club, haha.

I can't wait to watch the video man. Any way you could get the clip of you on T.V. as well?

Aw yeah, that would look sweet with some leather! Maybe hit it with some wood stain or something to match the leather as well...
Dang, if Jorge and Abo both make arm mounted crossbows/slings, then I need to make one. I already have an idea for one that uses yet a different design and material, so I'll have to see if I can work on that sometime.

AboMickey wrote:

If the rollers don't spin quickly you'll lose a lot o' speed.

You've finally built an arm mounted weapon, you are truly one of us now sir.

At release, the pressure on the rollers decreases immediately, friction is not so bad.

And yes, I have a lot of things to do for the cameras - the "looks" part takes longer than the build. Sanding, coloring, a nicer arm attachment.

True, my first arm mounted weapon! I'd love to make a nice double action knife, but that is sooo illegal here. Not that I am overly afraid, but I am a youtuber and can't show illegal stuff on my channel.

jawohl jawohl.

I understand, It's funny though that you can build all these truly devastating things, but because of a few regulations, you can't make a little knife.

Also, I love that Knot idea for the release string, so simple yet very effective. I was wearing my arm mounted crossbow the other night (which uses a metal ring and a string) and the ring got stuck on my finger... like really bad. I ended up putting oil all over my finger to get it off. Not one of my more graceful moments I'll admit.

another thing you might consider (and this is out there) is attaching a laser. these little guys can be hard to aim and if you can figure out how to make it laser guided it will make everything that much smoother. I'm just talkin out of my butt now.

I recentley became a member of the slingshot forum. I wanna get in on this zodiac contest you got goin on sir.

I might in fact attach a laser, I have several lying around. Have ordered a nice leather arm protector (archery gear), should be a good match. I saw a video with the ring system, and immediately thought "why not just make a knot into the string?").

Noticed that you plan to participate in the contest - good luck!

sneaky enought for mark I.
I think metal will fit into sleeve.

This...is simply awesome.

I have worked some on the weapon. Enhanced the wooden arrow clasp. Did a small paint job as well. And I replaced the ugly straps with nice leather.

It looks great so far!

How have you attached it to the leather bracer? I would guess just screws or something underneath. Is it something else?

I can't wait to see the finished result!

Yes, six spaxx screws with large washers.

You crazy bastard! I love it ... I had that same concept running around my head for a year now and never got around to doing anything with it. It looks great!

One question though, can you tell me a little more about how the paracord trigger works? I'm just not grasping it, and I will be building one of these shortly. A hand sketch or schematic would be great.

If I ever get back to Deutschland, we are definitely going to drink some beers together - my treat.

Here's your picture. It is the most simple construction one can possibly imagine.

Only idea that i can suggest is the use of steel. Tempered steel would work well, not to mention you could try thin springsteel on the area near the pulleys to add extra force. This could help make it more compact.
i love the idea, im going to try and make one out of steel with a tempered/spring steel comp . I\'ll upload a pic as soon as im done