working Repeating Crossbow

[Sangennaru]

Hello everyone!

Recently i saw an inspiring video, and i decided to build my own crossbow.
A WORKING, REPEATING crossbow!

of course, in scale.
It shoots three matches in three seconds, when it doesn't jam. It could be much better, but still it's impressive to have a working repeating crossbow smaller than a hand!

More on my website:
http://www.thelazyforger.com/tutorials/building-a-repeating-crossbow/





cheers,

Jack

[FramFramson]

Holy crap!

[Uncle Mike]

That is a bit good! Now I want one!

[Sangennaru]

I've got one. But i want more. I just can't stop shooting around matchsticks! and i'm getting better!

[tomogui]

ZOMG!

What an inspiring project, Jack! I want to build one too. Genius.

[former user]

 
where is the movie?
 

[Constable Bertrand]

Dog's danglies.     

Be careful if you decide to light the matches, you may loose the crossbow.

So what's next? A range of 1:48 working siege weapons (a new Bret trebuchet and Roman scorpions)??
Cheers
Matt

[Dr. Zombie]

Cool! I want one now.

[Sangennaru]

Thanks chaps!

For now, i'm ok with the crossbows, but i'm looking for a larger metal bow to make a slightly larger version of this, in order to throw barbecue sticks! ^_^

So what's next? A range of 1:48 working siege weapons (a new Bret trebuchet and Roman scorpions)??
Cheers
Matt

a LONG time ago i made a working Scorpion in 28mm.... eheh.
Unfortunately, resin doesn't react to stresses verywell, and tends to bend consistently over time. So... no mass production for those things! :S

[former user]

try acrylic plasticard, it can be lasercut.

You can provide the blueprint to @jimbibbly, he can probably cut them out, and You can glue them with plastic cement.

[Major_Gilbear]

Pretty cool, but I think you should put your engineering hat on and see if you can improve the design a bit more! 

For example, instead of having to crank the handle back and forth, it would be pretty cool to incorporate the returning part of the action with a finger trigger. Something like a spring (perhaps from a pen?) might help with this.

That way, each time you pull and then release the trigger, the crossbow "re-sets" so that you can fire it again. You'd have to practice a little so that you don't jam the mechanism by repeatedly pulling the trigger too quickly before it reloads itself, but it should be smoother to aim with and you can also fire it one-handed too.

What do you think? Can you improve on an ancient Chinese design? 

[Sangennaru]

I wanted to recreate the chinese design rather than improving!
I don't understand what you mean, though: The handle is needed to load the bow string in position, and to charge of potential energy the bow! Even with a trigger, you need to reload the bow before shooting again!

At the moment i don't have a great aim (nor the ancient chinese did) since the handle movement disturbs the aiming, but somehow i would need to load the crossbow!

[white knight]

Did you try lighting the matches? 

[Major_Gilbear]

Well, the action currently: draws the string, loads the next quarrel, and then releases the quarrel before you return the action to the start.

The first half of that action (draw-load-fire) is in one direction, and could be accomplished with a trigger action (i.e., squeeze a trigger). The second half of the action (returning the magazine to the front position so that it can start the cycle again) could be accomplished with a return spring (i.e., release the trigger and the spring pulls it pack into position).

There are lots of other methods actually (surprisingly interesting reading in fact), but this way you would basically still keep the Chinese mechanism and just change the way the mechanism is moved instead so that it doesn't require two hands.

[Sangennaru]

I still don't understand: The trigger is good for actually decide "when" to shoot, but the handle movement is required to draw the strings.

Unless you're saying that the force on the trigger should be enough to load the whole crossbow... but that requires a very strong trigger! The reason why that movement requires two hands is that it's hard to do, since you've to load a really stiff bow.

Or did i misunderstand what you mean?

Did you try lighting the matches? 

Not yet, but i will, for sure!