Totally off-topic, but still a very cool project.........

recumpence

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Hey Guys,

I am posting some pics of a project I completed for my boys. I know this is not a bike project, but, I figured you guys would get a kick out of this anyway. :D

My youngest son just turned 8 years old and has had alot of fun with Nerf dart guns. I went through the usual mods of the guns (removing the safetys, boring the air jets, stiftengng the spring, etc). However, it still wasn't enough. So, I made a few PVC pump-guns. These use PVC air pumps (made out of off-the-shelf PVC parts) that pushes air into the barrel. These guns have 3 times the muzzle velocity of the modified Nerf guns (radar varified :mrgreen: ). Anyway, that was still not enough. So, I went the air-cannon route.

I did some on-line research and found a number of guys making CRUDE garbage guns using pop bottles and other trash for parts. However, I could not find anything decent. So, I went to spud-gun sights. These guys are using sprinkler valves as air valves and "Schedule 40" PVC tube due to its high pressure rating. I used a few of their ideas. But, everyone needed to carry around a pump or large compressor to pressurize the darn thing. That seemed a bit lame. So, I decided to use an on-board compressor to recharge the chamber for the next shot. Lastly, the Nerf darts expand under the pressure and get somewhat stuck in the barrel. This slows down the dart. I did some testing and found that dry lube works best. The best dry lube I found for this purpose is Corn-Starch. Corn-Starch is the basis of Baby Powder. A simple dab of the dart in the cornstarch, a quick press of the compressor button and it is ready to fire.

The compressor is a $12.99 item I got at Auto-Zone (if I remember correctly). The sprinkler valve was $11.99 at Menards. The compressor is mounted in the lower aluminum box along with the small 3 cell lipo pack and misc wiring.

How does it perform? Phenominal! I tested one of the pump guns with my radar gun and clocked it at 280 feet per second. That gun gives 5 seconds of dart hang-time. This thing can loft a dart for 20 seconds! So, I figure it has a muzzle velocity potential of 1,000 fps! That is with 100 psi. This gun can provide 200 psi. But, that would just destroy the darts.

These light weight nerf darts slow down quickly from the air drag. The farthest I have shot a dart so far (75 psi) is 210 feet. I am sure 100 psi would give more distance. But, what's the point? As it is the dart is pretty much invisible for half the distance anyway. :mrgreen:

As I said, I know this is totally off topic and the mods are welcome to move it if they feel like it. But, I figured everyone needs a diversion now and then and a 8 year old birthday is just what it took for me to get the itch to try something new.

So, enjoy the picks!

Matt
 

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Nice job! A++++++


:)
 
HAHAHAHA absolutely brilliant Matt, your kids must be the happiest youngins on the block!!
Wait til they discover they can launch missiles OTHER than the foam nerf darts though Matt! ...potatoes anyone :mrgreen:

KiM
 
thats a great thing, adding another chamber would make a nice watergun, or it sputters icecubes for ur next coktail party :D
 
Hey Matt,

That's awesome. You would make Jamie from Mythbusthers proud. Your kids are having a great childhood. Have you put an astro in their powerwheels yet?

Clay
 
Hey Matt,
If you don't mind, could you share your electric lawn mower build with us. I'm interest in building one also and would like to reuse the ebike parts , especially the lipos :)
thanks, v
 
I haven't built the mower (yet). It is just a 110 volt Craftsman mower. I have not had the time to do a conversion on it. Heck, the only reason I did this gun was for my boys and it only took a couple hours to build. :)

I will eventually build a mower. When I do, it will be built all the way. :mrgreen:

We have shot the gun hundreds of times now. No problems.

I love buildiung stuff like this.

Matt
 
recumpence said:
I love buildiung stuff like this.

Matt

Isn't it the 'reason' we have kids though Matt? :mrgreen: so we can buy and make "toys" we couldnt afford or weren't around
when we were kids haha...as the saying goes Matt, the only difference between lil boys and big boys is the price of their toys hahaa

Look forward to seeing the 'mower' on future ;)

KiM
 
i had to look up what the hell nerf darts were :oops:
my only concern as Kim mentioned is what happens when they start putting in ball bearings? they're bound to target some random ebiker passing :shock:

D
 
years ago they were called 'potato cannons' (presume they still are?) You can knock holes
in fibre cement fencing no problems with them.

I am sure Matts kids are sensible and well behaved and listen to instructions though Deec...
or Matt wouldn't have made the 'gun' in the first place.

KiM
 
Hi Matt,

A simple dab of the dart in the cornstarch, a quick press of the compressor button and it is ready to fire.
One shot at a time? Sounds like revolutionary war level technology :p :lol:.

You should be able to do better than that!

How about fully automatic?:
images
 
No problem. The only thing needed is a constant supply of high volume, high pressure air. Full auto is no biggie. :)

I just ordered some rounds closed cell foam and soft rubber nose cones from McMaster to make my own darts.

These stock darts cannot take more than 80 psi. :twisted:

Matt
 
AussieJester said:
I am sure Matts kids are sensible and well behaved and listen to instructions though Deec...
or Matt wouldn't have made the 'gun' in the first place.

KiM


aye, im sure they are Kim, they sure will be some happy kids once they get into bikes :wink:

D
 
Well, gun development continues............

I have officially exceeded the capabilities of the stock Nerf darts and have begun making my own. A simple contact to McMaster Carr netted some foam tube and soft rubber button-plugs. I glued the plugs to the foam tube and wrapped some white electrical tape around the heads to make the diameter correct for the barrel ID. Wow, these things are insane! For one thing, they shoot straighter (more accurate), though they do wobble in the air a touch. They still follow a much straighter path through the air. Also, they have a bit more mass and are FAR more durable. At 100 psi, it shot through 3 layers of cardboard, through a 20 page booklet, and into another sheet of cardboard behind that. That is all with a projectile that weighs little more than a few sheets of paper. This thing would truely be deadly with a heavy projectile.

Oh, yeah, with these bullets, it has alot more recoil than it did with the stock darts. These darts are somewhere around $.25 each to make and about 2 minutes of time each. :)

Matt
 
Dude, that's insane. When my girl is old enough, I hope I can do the same.

I am curious, does the compressor get hot? I used one to power a backpack mounted squirt gun, and it got hot like no one's business. It actually melted. I might have been asking a bit much, about a cubic foot of air at 150 psi.

Oh, I'd be interested in seeing the pump guns and the new darts if you're so inclined to post a pic, link, or explanation. My nephew is major into the Nerf Warfare thing, it's his favourite game right now. The compressor version is perhaps a little more than they'd allow in the house, but the manual pumpgun sounds about right.

Katou

ps. I used to make little blowguns out of 1/2 copper pipe, darts were 6" of coathanger with a plastic cone taped on the end. They worked so well, it was kind of freaky. I always toyed with the idea of attaching my compressor to one, but even thinking about what that could do sort of made me shiver.
 
Around here they are called "spud guns". Used to light them with a bit of lighter fluid. They are seriously dangerous. We launched one in Flint,MI. When the potato went up and out of sight, we put the gun back in the trunk and got the hell outta there.
 
itchynackers said:
Around here they are called "spud guns". Used to light them with a bit of lighter fluid. They are seriously dangerous. We launched one in Flint,MI. When the potato went up and out of sight, we put the gun back in the trunk and got the hell outta there.
This is not a potato gun. I am totally aware of them. They are fun, but a bit hazardous. This is a bit similar, though. However, this gun is designed to fire .600 inch Nerf darts.

Matt
 
katou said:
Dude, that's insane. When my girl is old enough, I hope I can do the same.

I am curious, does the compressor get hot? I used one to power a backpack mounted squirt gun, and it got hot like no one's business. It actually melted. I might have been asking a bit much, about a cubic foot of air at 150 psi.

Oh, I'd be interested in seeing the pump guns and the new darts if you're so inclined to post a pic, link, or explanation. My nephew is major into the Nerf Warfare thing, it's his favourite game right now. The compressor version is perhaps a little more than they'd allow in the house, but the manual pumpgun sounds about right.

Katou

ps. I used to make little blowguns out of 1/2 copper pipe, darts were 6" of coathanger with a plastic cone taped on the end. They worked so well, it was kind of freaky. I always toyed with the idea of attaching my compressor to one, but even thinking about what that could do sort of made me shiver.

The compressor makes the aluminum box warm, but not hot. It only runs for a minute, then sits for a minute, then runs again. No biggie.

Here are a couple pictures. The first is the slug I made yesterday. I made six of them, actually. This is natural Delrin. It is machined to .60 caliber to fit the barrel. It is only .004" smaller than the barrel. So, it is a very good fit. The stock Nerf darts weigh less than 1 gram. This projectile weighs 5 grams. At 120psi it fired through 12 layers of thick cardboard. I also fired it at a 5 ply 1/2 inch thick ply wood sheet. It dented the plywood pretty deep (maybe 3/16 deep dent) and split the plywood on the back side. I think a 10 gram projectile would completely penetrate the plywood. I do not know the muzzle velocity of this thing. My radar gun will not pick it up. :shock:

The second picture/s is another air cannon I made. I wanted to see how simple I could make this setup. So, this cannon is simplicity at its finest. The sprinkler valve is modified to release pneumatically rather than electrically. I just attach a tire pump, give 10 pumps and it is up at 100psi. Then pick it up and fire. The recoil is similar (actually a bit more) than a small caliber rifle.

These things are crazy. It is nuts that anyone with $40 in their pocket, 30 minutes of time, and a little knowledge can walk into Menards and build a lethal weapon.........

Anyway, this has been alot of fun. The Delrin is 15 cents per round and 5 minutes to make each. The gun was only $38 and it only took 25 minutes to build.

My next project is to drill and tap a 1/4-20 hole in the tip of one of the Delrin slugs to thread an Allen bolt into it to up the weight to 10 grams and try the plywood experiment again.

Oh, the Delrin slug has no damage after that plywood shot. That Delrin is TOUGH
Matt
 

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recumpence said:
I just ordered some rounds closed cell foam and soft rubber nose cones from McMaster to make my own darts.

These stock darts cannot take more than 80 psi. :twisted:
Matt

Only you brother - well for the kids anyway :)

I played with rail guns a bit and built a few working prototypes but magnets of sufficient strength and size are just too damn expensive... so I got into modding paintball gear into automatic ball bearing guns, yep lipo powered and ammo hopper style :) {not for the kiddies but fun}

-Mike
 
Matt, thanks for the details on the pump gun. For some reason I was thinking that you had a plunger or something to compress the air instead of a bike pump. How would you get the valve to cycle fast enough to get more than one shot per reservoir of air? Guaranteed not all that air is needed to fire one shot. What is that little thing on the valve with the black button? How does that trigger the valve? Very, very cool.

And Mitch...

Automatic....Ball Bearing guns? WTF? For what, hunting deer? Holy crap dude, that's seriously lethal!

And my blowgun made me nervous... Remind me to keep the plumbing supplies and my antique ball bearing collection locked up with you around.

Yes, my collection of antique ball bearings. You have a problem with that?

I'm still looking for one of the ones formed by dropping from a great height, technique originated in Cincinnatti, 1914, back when Babbitt was king.

Katou
 
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