18 replies to this topic

[3DBBQ]

working good!

Edited by 3DBBQ, 30 August 2004 - 02:25 PM.

[ompa]

Wait- does it actually work? As in, give the dart some semblence of spin?

~ompa

[3DBBQ]

I pass through the test, the effect am not obvious, PissBacon' S dart, transfers quite intense '
,I think the my Barrel need improvement

Edited by 3DBBQ, 30 August 2004 - 02:45 PM.

[PissBacon]

What if you somehow bored spiral patterns into a barrel like a real gun?

[taita cakes]

You mean rifling?

Well, people have been over this many times, and generally, if i remember rightly, they were too light and did not travel fast enough to utilise the effect.

[Renegade]

What if you somehow bored spiral patterns into a barrel like a real gun?

This has been done before. Go to http://www.nerfworld.com/ and go to to the homemades section.

Edited by Renegade, 31 August 2004 - 03:14 PM.

[cxwq]

Rifling works with bullets because the lands (the opposite of grooves) cut notches into the bullet and permanently deform it into an impression of the barrel. A rifled gun barrel is actually smaller in diameter than the bullet it's designed for.

A nerf dart (if l/d > ~10) is a long cylinder that's heavy on one end and light on the other. It doesn't need extra stabilization as long as there is sufficient weight on the front and the dart is axially balanced.

[Viper]

What cxwq wrote is veryn true. If anyone of you guys actually saw a rifled bullet you'd quickly understand that it is not possible w/ a nerf dart. The hard bullets get torn up in the process and are expelled quickly. In the early paintball days they tried thicker paintballs and tried rifling, which would have worked if the paintball would have traveleved at a faster rate instead of the 200-300 FPS they usually get. The fastest I 've ever goit one up to is 400 fps, and i've heard rumors of 500fps w/ nitrous. A .22LR caliber bullet travels at 1100 fps(normal bullets) . 1500 w/ stingers. Many guns such as a 30-6 enfield reach 3600 fps ad .223 will fire 4000+ w/ hot military rounds. The largest bullet that I am sure of on quantity of full rotations is a .50 muzzleloader, which gets 1 rotation every 18inches of barrel and a nerf dart dwarfs that. Foam won't hold shape like metal will of course also. The only thing that will probably work would be spiral porting or putting backspin on the ball like the flatline barrel in paintball guns and the motorized ballzooka does. Not to blow sunshine up ur ass, but cxwq is a physics genius and his mods show it. I am in aw of your extensive knowledge.

Edited by Viper, 31 August 2004 - 08:16 PM.

[Vintage]

Another point to add to Cxwq and Viper is the force of the air behind the dart. The reason you may have an innaccurate gun could be due to fishtailing.

That is because the air, as it leaves the barrel behind the dart, pushes against the free flying dart causing it to wiggle in it's beginning flight. Even a spinning dart would encounter that force.

Like Viper said, porting eliminates fishtailing and riffled porting might give more accuracy.

Edit: What 3DBBQ did with the end of his barrel is a simple form that could give a similar effect. I personally think the spiral should go deeper on the barrel, so I might try my own experiments.

~Vintage

Edited by Vintage, 31 August 2004 - 08:49 PM.

[PissBacon]

So, since rifling doesn't really work with nerf because of the physics of it, I guess I'm unsure of why silencers work then. In a real gun, the silencer is intended to slow down the air so that it's not at supersonic speeds, preventing a sonic boom (I think that's how it works). I may just be confused.

[Vintage]

There is no real point to a silencer, I believe. Other than to hide a longer barrel. If it actually silences the gun, it is illegal. If you are shot at, unless it is pretty dark, you will know where the dart came from regardless of sound.

So, yeah, if I used a silencer, it would only be a mock that hides a longer barrel. Adds a cool touch.

~Vintage

[3DBBQ]

This kind of Barrel it affects the flash which comes out to Dart, reduces the air and the air contact , Fish tail is the Barrel terminal creates, therefore affects Dart the factor is in the Barrel terminal, is not in the Barrel
,Must let dart revolve is difficult

Edited by 3DBBQ, 01 September 2004 - 01:33 AM.

[Vintage]

3DBBQ, is the new spiral cut "terminal" helping to eliminate fishtailing?

~Vintage

[3DBBQ]

I as soon as start am the plan let Dart revolve, but the effect not greatly eliminates as if fishtails the travel to look like has effects, the Nerf series barrel terminal side has digs a hole I to think also is prevents to fishtail, but fishtails the travel most mainly or the Dart main body center of gravity question

[INsecurity]

I think i understand what he is saying, The notches cut out of the end of the barrel makes the air dispearse off the the sides insteaf of moving past the dart and destroying the air pocket that the dart is traveling on.

If you fire a dart the air will sit behind it untill it leave the barrel, this makes the dart go forwards, but once the dart leaves the barrel there is no more resistance for the air so due to it having less friction against the air than the dart it will travel past the dart and mess up the air around the dart causing it to fish tail.

Looking at 3DBBQ's barrel design it loosk as though it would make the air dispearse off to the sides more than straight ahead therefore affecting the dart less.

[FIDO]

I think i understand what he is saying, The notches cut out of the end of the barrel makes the air dispearse off the the sides insteaf of moving past the dart and destroying the air pocket that the dart is traveling on.

If you fire a dart the air will sit behind it untill it leave the barrel, this makes the dart go forwards, but once the dart leaves the barrel there is no more resistance for the air so due to it having less friction against the air than the dart it will travel past the dart and mess up the air around the dart causing it to fish tail.

Looking at 3DBBQ's barrel design it loosk as though it would make the air dispearse off to the sides more than straight ahead therefore affecting the dart less.

Actually, he wants the darts to spin. we have been trying to make a dart that spins for greater accuracy, just like rifling. we just don't have sraight enough darts to make it so it doesn't fishtail. I think it is either with the straightness of the dart, or like what 3DBBQ said that the darts just need more weight. Oh, and that brings up a question: 3DBBQ, what kind of weights did you use?

[INsecurity]

The whole rifeling thing has been done to death, the only real was is to add fins to your darts, Cutting them does work but takes way too long. so you best bet is to just add fins on the bacl not the side.

[Fuse]

I think i understand what he is saying, The notches cut out of the end of the barrel makes the air dispearse off the the sides insteaf of moving past the dart and destroying the air pocket that the dart is traveling on.

If you fire a dart the air will sit behind it untill it leave the barrel, this makes the dart go forwards, but once the dart leaves the barrel there is no more resistance for the air so due to it having less friction against the air than the dart it will travel past the dart and mess up the air around the dart causing it to fish tail.

Looking at 3DBBQ's barrel design it loosk as though it would make the air dispearse off to the sides more than straight ahead therefore affecting the dart less.

Have things like this been tried before? Because it seems like a pretty good idea to let the air disperse off to the sides rather than continue to manipulate the dart once it no longer has the guide of the barrel.

[Vintage]

Most air guns work best with ported barrels. Most people know this, and if they invest the time, use them. For my stronger air guns (at2k, blastbazooka) I use ported copper over brass, or ported PVC over brass. 1/2" copper fits perfectly over 9/16 brass, so it is a good choice for the job. Only problem is that it adds weight which needs support.

~Vintage