92 replies to this topic

[taita cakes]

I don't know who exactly I'm replying to because I'm reading this on and off in my design class.

I struggle to see how my film canister design, the "Anzac Nade", could be propelled that fast to cause that much damage really. I also don't really see how it could be flung that fast without opening either, but I suppose you probably want it to open in mid air. Also, the worst you can do is be copped with the flat end of the film canister, which would be somewhat like being hit with a fat stefan, only plastic.

Also, the names Tait

Can't wait to see the video [when I get home]. Sounds good.

[GeneralPrimevil]

Tait, you forced me to sign in. Why?

First off, 80 psi against a film canister filled with sand, in my experience, has enough energy behind it to easily take out a squirrel. Its energy at 100ft. is more than a .22 long's. I think I will make a video especially for you so as to show you the shear power of a cannon with 3 gallons of air behind the projectile. It is incredible. I once used a PVC rocket to accidentally take down a tree branch. The branch was only an inch or two in diameter, mind you, but still...

Hey CS, in my opinion your first design is far superior. I dunno why, but it probably is my inability to conceive how that latest one works.
I'm also going to modify that first one to try and solve some of the problems you described. I'll post what I get as results probably after Wednesday, since that's when my new barrel comes in . I think I might have to make a breach for it...mmm...steel...the Yoda of building materials...

Well, the sun's setting over here, so I can't really do much else today. That vid will be taken hopefully tomorrow. If not, expect the thing CS is designing to have a vid on Thursday.

Again, remember that these cannon are capable of massive power. I mean, with the right valve, a 20oz soda bottle full of water can easily be sent through 3/4" plywood at a hundred feet.

Ha, I need to get sound of my cannon firing that casing I made at 80psi. It's so much louder than anything else I've fired due to the seal the plastic bag makes....

[Flaming Hilt]

Hey, if you wanted to get CS's idea in mid-air, you could parachute -just- the door.

[taita cakes]

GeneralPrimevil, on Apr 10 2006, 10:56 AM, said:

Tait, you forced me to sign in. Why?

Because you did the same to me

But yeah, I just don't see the need for all that PSI, honestly.
The only dangerous end of a film canister is the ends. Pad them out and you're set.

[nerfer34]

So are nerf guns considered to have PSI?

[Flaming Hilt]

If it uses air pressure, it has PSI.

So pump guns, yes.

Plunger guns... maybe. The idea behind a plunger is more to move the air around than to pressurize it.

[nerfer34]

OKay thanks

[CaptainSlug]

GeneralPrimevil, on Apr 9 2006, 03:56 PM, said:

Hey CS, in my opinion your first design is far superior. I dunno why, but it probably is my inability to conceive how that latest one works.

The first one may not work for the following reason.
The cannon will be pushing the dart from the rear, but the front part of the dart will be in contact with the inside of the barrel. The result is that the accelerating force and friction resistance might set the granade off as soon as it's fired. The cardboard tube, in order to not be moved to the open position by friction with the barrel, needs to open towards the front of the dart rather than towards the rear.

All of the darts function from the same principle. One part of the dart comes to rest before the other. Here's what happens after they run into something or the part the chute is attached to is decelerated.


The first one will need some weights added to the cardboard tube "door".
The second one might work best because the part that decelerates last has more weight. Both could be tested quite easily by simply throwing them.
When I'm not so busy I might make a few of these out of pipe insulation, FBR, and scrap plastic.

taita_cakes said

The only dangerous end of a film canister is the ends. Pad them out and you're set.

That's assuming it's flying straight with weight balanced towards the front. Before the chute opens, a cylindrical projectile that's not spinning or drag corrected is just going to tumble. If you fire any amount of hard material from a gun that you want to be "safe" you MUST encase the projectile in a hefty layer of foam AND provide an ample amount of surface area to divide the load over.

Flaaming Hilt said

Plunger guns... maybe. The idea behind a plunger is more to move the air around than to pressurize it.

They build up pressure behind the dart to overcome friction. If the plunger gun can't build up pressure behind the dart then the dart isn't going to go anywhere.

Edited by CaptainSlug, 09 April 2006 - 11:03 PM.

[Flaming Hilt]

CaptainSlug said

They build up pressure behind the dart to overcome friction. If the plunger gun can't build up pressure behind the dart then the dart isn't going to go anywhere.

Right. The air moving from behind the dart has to build up that pressure. I guess it has a little to do with both.

I don't get how the second one works. It looks to me like it's the same thing, just without the door so the stefans could fly out right away. Or is the back part the door?

[CaptainSlug]

On the very last one the "door" is attached to the tail. The nose cap, rubber bands, and the rods holding the rubber bands are the parts that move. It's best to have the heaviest part be the one that gets decelerated last so that it can overcome the friction of the darts against the inside of the door.

Edited by CaptainSlug, 09 April 2006 - 11:29 PM.

[CaptainSlug]

GOOD NEWS
If anyone wants a foldable frisbee to use as a barricade buster I will soon have enough for everyone that wants one (or two) and hasn't been able to find them.

[Lutinent Cole]

This is kinda off topic, but since you guys are the leaders, or so I see, on making darts go everywhere does someone know how to make a Titan into a shotgun, or have a grenade and a modd that allows it to fire a grenade

[Renegade]

CaptainSlug, on Apr 10 2006, 05:38 AM, said:

GOOD NEWS
If anyone wants a foldable frisbee to use as a barricade buster I will soon have enough for everyone that wants one (or two) and hasn't been able to find them.

There go my dreams of selling semi-official Barricade Buster's.

I'm still cooking up some grenade launcher stuff. I'll post any good finds.

[nerfer34]

Captain Slug I'd love to have 2 foldable frissbees for the baricade busters. How much would they cost? Thanks.

[CaptainSlug]

nerfer34, on Apr 10 2006, 12:28 PM, said:

Captain Slug I'd love to have 2 foldable frissbees for the baricade busters. How much would they cost? Thanks.

Once I have them in my hands I'll post a thread in the Trading section.

lutinent cole said

This is kinda off topic, but since you guys are the leaders, or so I see, on making darts go everywhere does someone know how to make a Titan into a shotgun, or have a grenade and a modd that allows it to fire a grenade

This is the wrong forum section for that. Check the sticckied threads in the modification forum.

Edited by CaptainSlug, 10 April 2006 - 04:29 PM.

[nerfer34]

Guys I just got an ingenius idea on a nerf grenade. I really think I can easily design a working one! I'll get up pics later and since I'm no good at making homeades maybe someone else can try it. But my Idea is fool proof so far and will have a VERY effective blast(no co2 or gas or anything).

Edit Okay Here it is
nerf nade(my best one yet by far)

The little "pin " type thing hits the wall triggering the realese valve which releases the air and making the stefans come out back.

Edited by nerfer34, 10 April 2006 - 05:33 PM.

[Flaming Hilt]

I think Nerfer34 has an interesting idea. It's smart to use air to blow the darts out the back -- and more effective than sending them out parallel to the wall (no offense, CS). I think the air compression idea also makes it more Nerf.

The problem is getting the trigger system down. I don't think a pin would work too well, and it's dangerous as well. But using an At2k isn't a bad idea. Maybe have the pump glued inside of one side. Just take out the goo tube alltogether (yes, I have done this), and then hack off the barrel and rotate it to face out the rear of the projectile, which would be filled with darts.

The problem (I'm repeating myself... NO!!!) is the trigger system. I have no ideas.

[Lukeinator]

A few problems.

In order to release the air from an AT2K tank, or any other nerf gun thank for that matter, the valve pin is puled out by the trigger, not pushed in. Unless you can somehow rig up a contraption to pull the pin out, it won't fire.

It also seems as if the stefans would just fly in one general direction, not all over the place like a grenade is supposed to.

And... How are you going to prime the AT2K tank? Will you have a detacheble (sp?) pump with a threaded attachment? Actually, that wont work umless you put another valve on it because, from my understanding, there is no check valve on the tank. That would be a major problem if it couldn't hold air.

Edit: Flaming already came up with and idea for priming, it would get kind of bulky in my opinion though.

Edited by Lukeinator, 10 April 2006 - 05:56 PM.

[GeneralPrimevil]

First off, don't worry about a trigger system for that. Second, don't worry about filling either. I have both covered already. Remember my SOBR? Yeah, threading an AT2k vavle for 1/4" NPT is easy, as long as the valve is not modified as the one I had was.

As for actuation, well, nose cone with a lever. I still have 1/4" SS square stock. If anyone has pulled apart a keyboard they know how I can get that force distributed evenly across the whole shmear.

That 'nade would be really damn heavy. Any ideas (besides using helium in the cannon)?

My shotshell failed finally. It shoots straight for the ground since I added a new 'chute to it. Well, time to make some of CS's torpedoes...

[CaptainSlug]

Building a pressure tank system into a grenade will make it too heavy to be safe for propulsion out of a cannon. Plus trying to fit everything you need for one to work inside a 2" inner bore cannon would be difficult.
A pressure grenade of some kind would be fine as a hand grenade if you can figure out a safe and reliable configuration. They're much harder to make than something powered by elastic force.

Edited by CaptainSlug, 10 April 2006 - 08:14 PM.

[nerfer34]

OK I had a dentist appoinment and now I'm back..... Well thanks for the comments. Anyone feel free to change my idea in any way. Yes I think the biggest concern is the trigger and how it pushes in instead of out. Grimevil- YOu say you can make a trigger design that will work? I'd be pleased to hear it..... Also Yes I think the pump would be detachable. You would just pump into the air tank and detach it and launch the grenade. If anyone has any ideas on the trigger or any other improvments please tell me! Thanks

[Lukeinator]

nerfer34, on Apr 10 2006, 05:24 PM, said:

Also Yes I think the pump would be detachable. You would just pump into the air tank and detach it and launch the grenade.

You are still going to need some type of check valve to keep the air in the tank. Mabye a very tiny ball valve.

Edited by Lukeinator, 10 April 2006 - 11:24 PM.

[CaptainSlug]

I pulled some inspiration from the paintball work my friend was unsuccessfully trying to convince me I should do. I came up with this tank/valve configuration that would be fairly easy to make.

I can use the same tank design to make a rearward-firing mortar with only a few modifications.

Edited by CaptainSlug, 11 April 2006 - 10:27 AM.

[nerfer34]

CS- I'm a little confused with that pic.....

Lukeinator yes I would probably need a small valve but I believe the sell very tiny lightweight valves that wouldn't affect it much. Thanks for your comments.

[DTReaper]

Slug that looks like it has some potienal A single valve opening into many short barrels but for the amout of barrels that are in the pic you will need a pretty big airtank. There is also another problem where if the bottem barrles fire faster than the top then there won't be as many darts in the air and the scatter might be affected. Also I would stagger the holes in the round if possible so the scatter is better. But overall it shows more potential than any of the explosive ones that have been suggested from time to time.

-DTR