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Posted: Fri Dec 28, 2007 6:17 pm
by jackssmirkingrevenge
jon_89 wrote:do you remember what size syringe you used?
The biggest I could find, 50mL

Posted: Fri Dec 28, 2007 9:14 pm
by jon_89
When you said it when through a cd case how far away was the shot taken? Any ideas how to make it stronger? I am curious because after looking at how simple this is I think this will put a hold on my alternative power search?(for awhile any ways)

Posted: Fri Dec 28, 2007 11:31 pm
by jackssmirkingrevenge
jon_89 wrote:When you said it when through a cd case how far away was the shot taken? Any ideas how to make it stronger?
That was from 5 metres. You can make it stronger by increasing the length and number of rods that make up the bow, and for example instead of using a syringe tube, using a tube and plunger from a bicycle pump ;)

Posted: Sat Dec 29, 2007 1:06 am
by qbnbountyhunter
That is so sick, If only it still worked... How fast do you think it fires, or how much muzzle energy? Its so simple, but very unique. I like it cause its an example of power that alternative to springs.

Posted: Sat Dec 29, 2007 1:09 am
by jackssmirkingrevenge
It was probably around 150-250 feet per second for 0.20 gram BBs

Posted: Sat Dec 29, 2007 1:15 am
by jon_89
how could i make my own plunger? what was used to hold the bb in place? could i use something besides piano wire?

Posted: Sat Dec 29, 2007 1:16 am
by qbnbountyhunter
That is very nice. Equal to a high grade spring pistol. Beautiful, especially for an airgun that is around eight years old.

Posted: Sat Dec 29, 2007 1:34 am
by jackssmirkingrevenge
jon_89 wrote:how could i make my own plunger? what was used to hold the bb in place? could i use something besides piano wire?
Something like this would be a perfect plunger, you might just have to widen the nozzle to 6mm.

I connected the barrel to the nozzle with a piece of silicone tubing (the sort used in model aircraft engines as fuel line), it was that which kept the BB in place, but you can use an o-ring, rubber tubing or similar.

Piano wire is the best material as you can install it in separate rods instead of one bow, it's very tough and springy. The only practica alternative I can think of is a coil spring.

Posted: Sat Dec 29, 2007 12:35 pm
by bob-a-lu
you know what jsr i bet that if you designed weapons this stupid war would be over by now and osama would be cutting my grass.

Posted: Sat Feb 09, 2008 3:13 pm
by Antonio
Looks pretty cool! I tried it once and found out that my bow was too heavy>slow to fire the small 0.12g pellets.

Posted: Sun Feb 10, 2008 6:46 am
by Brian the brain
you know what jsr i bet that if you designed weapons this stupid war would be over by now and osama would be cutting my grass.


If you think he should be designing weapons of war you are on the wrong website, buddy......


Jsr is not stupid and with 4733 posts he deserves more respect than that.


I mean....some of those posts made sense, you know

Posted: Sun Feb 10, 2008 11:11 pm
by Solar
Sorry if this is redundant but I really do love this air gun crossbow semi design. Even if the rof was a little unrealistic in the movie it is way cool and seemingly a sound design.

Image

Re: 6mm crossbow project

Posted: Sun Jun 28, 2009 2:31 pm
by boyntonstu
jackssmirkingrevenge wrote:Placed in the mini-section because it didn't seem to fit any other category - this is a project I made for school back in 1999, it was my first ever projectile firing device. I was very into model aircraft at the time, you can see this from the materials and style of construction. The design is basically the same as a spring airsoft pistol, but instead of using a coil spring, the power comes from a crossbow style spring made from a bundle of piano wire rods.

I decided to post it now as there seems to be a considerable interest in spring-piston type airguns on the forum at the moment and some might find it a useful reference. It was quite a powerful creation for my first project, it would put a 6mm BB clean through a CD case.

The prototype is a bit dusty from hanging on my wall for so many years and is a bit worse for wear but you can see from the diagrams what it originally looked like. The drawings are self explanatory but of course any queries are welcome :)

VERY impressive!!


Consider the Airowgun.

It shoots a .22 at 600 fps with a 60 pound pull (if you believe the videos and the spec).

Working backwards, what homemade airgun design would match that performance?


What would you expect out of a 150 lb crossbow and a 24" stroke?


BoyntonStu

P.S. My $100 elevator


Posted: Sun Jun 28, 2009 3:51 pm
by twizi
dude this topic is a year old

dont :banghead: post :banghead: on :banghead: dead :banghead: topics :banghead:

you make me angry

Posted: Sun Jun 28, 2009 3:58 pm
by boyntonstu
twizi wrote:dude this topic is a year old

dont :banghead: post :banghead: on :banghead: dead :banghead: topics :banghead:

you make me angry
"dude this topic is a year old" Terrific!

I joined today so please point me to the thread.

Thanks,

BoyntonStu