Search found 33 matches

by KineticAmbitions
Wed Sep 30, 2009 4:56 pm
Forum: Miniature Guns
Topic: combustion airsoft pistol
Replies: 34
Views: 5510

Unless I'm severely mistaken, this is incorrect. Muzzle energy and recoil energy have to be equal, it's a fundamental law of physics. For every action there is an equal and opposite reaction. How the recoil feels is completely dependent on how quickly the energy is transferred to your body and how ...
by KineticAmbitions
Tue Sep 29, 2009 7:14 pm
Forum: Miniature Guns
Topic: combustion airsoft pistol
Replies: 34
Views: 5510

No the mass of the weapon itself determines how the kick feels, whether it accelerates or jerks. However the power of the kick is all determinant on the time it takes to recoil. Either way the same amount of energy is being absorbed. Muzzle energy is NOT equal to recoil energy. The recoil energy va...
by KineticAmbitions
Mon Sep 14, 2009 7:55 pm
Forum: General How-To & Discussion
Topic: Cannon energy contest
Replies: 65
Views: 2707

Wait...is that a joke? Are video games banned as well? They better ban rubber band guns next since they resemble weapons of mass murder. Also, i'd be shocked to see Peter Pan books remain legal since they contain sword fights, clearly conditioning Austrailia's youth to be blade toting throat slashe...
by KineticAmbitions
Mon Sep 14, 2009 5:43 pm
Forum: General How-To & Discussion
Topic: Cannon energy contest
Replies: 65
Views: 2707

we could use a notebook paper penetration method. To be honest, a plastic BB being flung by a mechanical system is not going to go very fast. So we could use a box o truth method simply using sheets of paper. Have we agreed that it will be restricted to mechanical launchers? If only pneumatic and c...
by KineticAmbitions
Mon Sep 14, 2009 5:17 pm
Forum: General How-To & Discussion
Topic: Cannon energy contest
Replies: 65
Views: 2707

Using a plastic BB doesn't eliminate railguns, it would just require the use of an aluminum or copper sabot. Coilguns could be used as well, but I've not seen one that reaches high enough muzzle speeds to be competitive in such a contest. If anyone can build a railgun or ETG which could compete here...
by KineticAmbitions
Mon Sep 14, 2009 4:21 pm
Forum: General How-To & Discussion
Topic: Cannon energy contest
Replies: 65
Views: 2707

How about this: fastest projectile without the use of combustion or pneumatics? Projectile being a toothpick... That would include everyone and show ingenuity of the builder That does sound like a very good idea. It involves significant ingenuity not only in developing new propulsion systems, but i...
by KineticAmbitions
Sat Sep 12, 2009 11:22 pm
Forum: General How-To & Discussion
Topic: Cannon #4 - Cobra Striker
Replies: 21
Views: 18377

Very clean build, if not perfectly implemented yet. I'd really like to see more details on that valve after the votes are all in, and ask the owner how those burns on his arms feel. Unfortunately, those little oxygen tanks run out quickly, and are very expensive. Mostly well built and effective, but...
by KineticAmbitions
Sat Aug 15, 2009 4:39 pm
Forum: General How-To & Discussion
Topic: 8x pvc failure
Replies: 38
Views: 3526

But I was remembering this lecture a cop gave me as a juvenile about some kid who had put a pipe b*mb inside one, electrically ignited it, got hit in the head with a cinderblock chunk and was drooling and wears a helmet all the time... Are you sure he wasn't drooling and wearing a helmet before he ...
by KineticAmbitions
Thu Aug 13, 2009 9:05 pm
Forum: General How-To & Discussion
Topic: 8x pvc failure
Replies: 38
Views: 3526

What you're seeing here is less likely to be DDT than it is the result of pushing an unsafe building material past its limits. It is well established that PVC is brittle and, being a plastic, has a very low tensile strength compared to that of even mild steel alloys. Consider the case of a very larg...
by KineticAmbitions
Tue Aug 11, 2009 10:39 pm
Forum: Combustion Cannons
Topic: Does it count as a firearm?
Replies: 40
Views: 2306

In most places, the cops require a warrant to enter private property without the owner's permission. To get a warrant, they need to convince a judge that, one, a crime has occurred, and two, that there is reason to believe that you have something to do with it (or pay him a sufficiently large sum of...
by KineticAmbitions
Sun Aug 02, 2009 1:50 pm
Forum: Pneumatic Cannons
Topic: Punkin' Chunkin' 2010...
Replies: 66
Views: 4357

A 20 foot long barrel is not going to be successful here - the ranges of the competitive launchers suggest trans-sonic muzzle speeds. Reaching those speeds in a 20 foot long barrel would require accelerations which would surely smash the pumpkin. Hence, the extremely long barrels used by the serious...
by KineticAmbitions
Sat Aug 01, 2009 9:52 am
Forum: Pneumatic Cannons
Topic: Punkin' Chunkin' 2010...
Replies: 66
Views: 4357

If you have the money, the air could be made extremely hot through shock compression, like a springer but with air moving the piston. Simple adiabatic calculations show that almost twice ambient temperature could easily be reached by compressing a sample of air to one quarter of its original volume....
by KineticAmbitions
Sat Jul 25, 2009 8:26 pm
Forum: Pneumatic Cannons
Topic: self filling gas
Replies: 9
Views: 456

There's nothing against the forum rules about using chemical reactions such as Al/HCl, or phase changes such as off-gassing dry ice as pressure sources. There IS something against the rules about exploding containers with them. The CO2 method has been used before, and works, although it is rather da...
by KineticAmbitions
Sun Jul 19, 2009 3:50 pm
Forum: Combustion Cannons
Topic: How to seal spark gap to for high pressure and what to use?
Replies: 9
Views: 1373

I've seen it accomplished nicely using two lengths 14 gauge solid copper wire wrapped in electrical tape. They are then both passed through a 1/2" brass cap with a 1/2" hole drilled through the top, and the cap is filled with JBweld or some other epoxy. The ends in the chamber are bent toward each o...
by KineticAmbitions
Sun Jul 12, 2009 8:55 pm
Forum: Off-Topic Hobbies
Topic: ETG Help
Replies: 19
Views: 1799

A single small strip of aluminum foil should be vaporized by 75J. You will, however, need a very efficient design before you can actually move something out the barrel with that little energy. The average amateur ETG design would be lucky to gently lob an airsoft round out the barrel with 75J input....