Pump Action Pencil Launcher

Status
Not open for further replies.

JoergS

Member
Joined
Oct 1, 2009
Messages
337
A pencil can be very dangerous - when The Slingshot Channel builds a weapon around it!

The "Nerd Revenge 2000" is a homemade pump action slingshot crossbow that can fire 10 razor sharp pencil in under five seconds. The "arrows" travel at an impressive 100 miles per hour, fast enough to go through a
apple!

The compact weapon (24" = 60cm) can also fire a "devilled" version if a pencil, with an achery field tip glued in. Then the once so harmless pencil is turned into a deadly projectile!

The design was inspired by the Chinese Repeating Crossbow, but the awkward repeating action has been replaced by the far better "pump gun" method. The rubber bands are pre-tensed to 300% and stretched to 500% when you shoot. This means you get good power at a relatively compact size. My experiments with super slomos and the thermal test series laid the
ground for this new concept.

This is probably the most fun slingshot I ever shot!

http://www.youtube.com/watch?v=PYJ2zj1SB5Y
 
LOL. Genius!

And well executed craftsmanship - as always.

( ... i´d be willing to buy a slingbow off of you ... if u care to part with one)
 
Wow, I loved the Chinese repeater crossbow design when I read about it as a kid. The pump action is way better, at least with the light tension of a rubberband.
 
I just had to do it. Against all odds.

I doubled up the rubber.

Now we are talking!

The stronger bandset pushes the weapon into the realm of deadly weapons. The pencils now go through a rubber door mat, which withstands the 20 mm steel ball hits from my strongest slingshots!

As a matter of coincidence, some better quality pencils arrived (Faber-Castell HB, 1,18 Euros for twelve pieces including tax). Much more solid. Just in time.

But in order to push the envelope even farther I took a damaged carbon fibre arrow shaft, sawed it into five pieces and glued tip holders in. Then I screwed the field tips in. The arrows now weigh 9,6 gramms (154 gr).

The impact is absolutely astounding. They go into a massive wooden plank and I need tools to get them out again. They even pierced through a PET water bottle and still stuck in the plank. Distance 8 meters, the flight is absolutely stable.

I reinforced the string catchers (glued in a steel nail in fact), so the weapon withstands the much harder impact of the 300% pretensed bands (3,5 cm x 2,5 cm x 11 cm relaxed length).

Newammo.jpg

Newammo2.jpg

Newammo3.jpg

Newammo5.jpg
 
Absolutely Incredible! The only way it could be any cooler would be to somehow give the barrel some rifling and impart a little spin on the pencil to stabilize it. :)
 
Hmm, with the improvements on the ammo, you actually have a home defense weapon, donacha...
Very cool, sir, and thank you - you always have a lot of fun with it!
 
JoergS I always enjoy your inventions and videos.

All I can say is your friend Tobias is one strong son of a gun. I say that as a 60 year shooter of slingshots and know how hard it is to just bring a slingshot with powerful bands back to release position. But then to remain steady under that stress and make aimed shots is a great accomplishment.

About 30 years ago I made a shoulder fired, trigger release slingshot gun to shoot .45 caliber lead balls. It was a very compact unit for carry with bands relaxed, the forks were on an extension, which extended out and stretched bands to maximum reach, where it then latched in battery. It was powerful in warm ambient temps, but a big disappointment in even moderately cool weather. As the rubber bands was using at that time would become very sluggish and lose power dramatically, when it got very cold, they became useless.

I noted there is rubber pallet bands for freezer use. Do they retain their elastic characteristics at cold temperatures?
 
Hang fire, good rubber needs to be free from chemicals. So freezer bands would do poorly.

Slingshot bands work OK in any temp that is above freezing, but the colder the weather, the thicker the rubber must be. The draw weight simply goes down in the cold, and so does the power of the shot. You can compensate by using more rubber when it is cold.

Tobias is very strong, as most farmer boys are. They work hard, every day.
 
Status
Not open for further replies.
Back
Top