Homemade Rocket Launcher

[Nikpo]

I'm looking to build an RPG-27 or a LAW or someshit for airsoft, as it'd be a blast to use in games, but I haven't any idea how the triggering mechanism would work, and how exactly it'd launch a projectile. (I.E. Nerf football)

I'm thinking of building a tube that'd house a 40mm grenade, and use it like an oversized grenade launcher, but some exact specifications and stuff would be nice. (I'm sure Timebomb can help me out here.)

I need it relatively light, so I'm not going to make it out of metal, maybe PVC piping?

[Stupideye]

PVC piping would probably be your best bet.

[Timebomb757]

Would you want it to fire using 40mm grenades or air compression?

[editline]02:27AM[/editline]

[QUOTE=Stupideye;25237337]PVC piping would probably be your best bet.[/QUOTE]

Depends really. For air compression you would want a metal air-chamber for durability reasons.

[Nikpo]

All I'm looking for is to fire either a bunch of BB's or a Nerf football, and it sounds like the 40-mike's can do both, and are more convenient to re-arm.

Not sure how I'd go about making a trigger mechanism for it though, and how to lock a 40mm grenade into the rear of the launcher, while still able to release it easily. (With a button?)

[deathmog]

Look up a guy named Aderonn on youtube, he made a RPG and another grenade launcher using PVC and Caulk guns, I followed his tutorial and made a 40mm grenade launcher and it works great.

[Nikpo]

I think I remember seeing those videos. I'll take another look through those, thanks.

[Timebomb757]

[QUOTE=venom;25237409]All I'm looking for is to fire either a bunch of BB's or a Nerf football, and it sounds like the 40-mike's can do both, and are more convenient to re-arm.

Not sure how I'd go about making a trigger mechanism for it though, and how to lock a 40mm grenade into the rear of the launcher, while still able to release it easily. (With a button?)[/QUOTE]

40mm can do both, but the barrel needs to be somewhat short since a 40mm doesn't really hold much gas.

As for a firing mech:
[media]http://www.youtube.com/watch?v=KRgSqggZ9y0[/media]

This is the least complicated type Ive seen so far.

[editline]02:37AM[/editline]

Honestly though, if you want to use 40mms, its easier just to buy an M203 or standalone launcher. The only reason I would carry around a rocket launcher is if it performed better than an M203, which a 40mm really wouldnt.

If you put an in-line pneumatic cannon inside a rocket launcher body (Or just paint the cannon itself) and run a Co2 rig, you can punch footballs out past 150 yards. And they can be trigger-fired as well.

[Nikpo]

[QUOTE=Timebomb757;25237464]If you put an in-line pneumatic cannon inside a rocket launcher body (Or just paint the cannon itself) and run a Co2 rig, you can punch footballs out past 150 yards. And they can be trigger-fired as well.[/QUOTE]

150 yards? That would be pretty cool, although I dunno if I want to run a CO2 rig.
How far would a 40mm grenade launch a football? Think there's a way to increase that by modifying the grenade itself or something?

[Timebomb757]

[QUOTE=venom;25237645]150 yards? That would be pretty cool, although I dunno if I want to run a CO2 rig.
How far would a 40mm grenade launch a football? Think there's a way to increase that by modifying the grenade itself or something?[/QUOTE]

Depends on the grenade really. A high-capacity one could probably launch a football 250 feet out of a 1.5 foot barrel.

[Taepodong-2]

Make a SMAW. You can split it into two parts for easy transport and have your CO2 rig in the back part and then stuff your Nerf football in there somehow.
[img]http://www.designation-systems.net/dusrm/app4/smaw-1.jpg[/img]

[Nikpo]

Eh, I'm pretty much decided on the RPG-26. I'm working on getting some basic measurements of the RPG-26 now.

I'm thinking I'm going to use a 40mm grenade, just simply because of how much easier it'd be (maybe) than carrying a CO2 rig.
So far the problems I'm having is:
The trigger for the 40mm would (preferably) be a button on the top, not sure how to make that work.
The barrel needs to be relatively short. (right now measured at ~286mm (~11"))
and I need to figure out a way to lock the grenade in there.

[editline]08:38PM[/editline]

Here's the measurements I've got so far:
[img_thumb]http://filesmelt.com/dl/RPG-26.jpg[/img_thumb]
(I think my math is relatively solid.)

The final product won't be dead-on accurate, just relatively to scale to the real thing.

[editline]hgn[/editline]
Math on a Sunday.. wooo.

[Sweetie]

Please please please use pressure rated pipe.

[Timebomb757]

[QUOTE=Sweetie;25251540]Please please please use pressure rated pipe.[/QUOTE]

Wouldnt matter with a 40mm, the firing pressure isn't high enough to burst even cellucore pipe, and all of the held pressure is contained inside a metal M203 round.

With Co2 or HPA (as I suggested) you would want black iron or solid core PVC (Preferably black iron). And obviously use the properly rated fittings and cements. Safety first kids :eng101:

[Nikpo]

[QUOTE=Timebomb757;25253650]With Co2 or HPA (as I suggested) you would want black iron or solid core PVC (Preferably black iron). And obviously use the properly rated fittings and cements. Safety first kids :eng101:[/QUOTE]

So, if I were to use a CO2, instead of having to run a rig on me, would I be able to fit some sort of container for the CO2 in the rear half of the tube? I'm only planning to use the first part of the tube as the actual barrel and chamber (the 286.39mm part of the launcher in the pic above).

Would I be able to fit some CO2 container in the remainder of the rear tube?

[editline]ads[/editline]

Something like this:
[img]http://filesmelt.com/dl/RPG-262.jpg[/img]

Where red would be the chamber/barrel, and blue being where the CO2 container would be.

[Sweetie]

[QUOTE=Timebomb757;25253650]Wouldnt matter with a 40mm, the firing pressure isn't high enough to burst even cellucore pipe, and all of the held pressure is contained inside a metal M203 round.

With Co2 or HPA (as I suggested) you would want black iron or solid core PVC (Preferably black iron). And obviously use the properly rated fittings and cements. Safety first kids :eng101:[/QUOTE]

Oh, I thought he was using a pressurized air rig.

[Timebomb757]

[QUOTE=venom;25254027]So, if I were to use a CO2, instead of having to run a rig on me, would I be able to fit some sort of container for the CO2 in the rear half of the tube? I'm only planning to use the first part of the tube as the actual barrel and chamber (the 286.39mm part of the launcher in the pic above).

Would I be able to fit some CO2 container in the remainder of the rear tube?

[editline]ads[/editline]

Something like this:
[IMG]http://filesmelt.com/dl/RPG-262.jpg[/IMG]

Where red would be the chamber/barrel, and blue being where the CO2 container would be.[/QUOTE]

If I remember correctly, a 9oz Co2 bottle fits nicely into 2.5 inch SCH 40 pipe. You would probably need spacers of some kind to keep it stable in there though.

On the other hand you could just put a pressure chamber with a Shrader or Q/D feed in the back and just have the Co2/regulator in a backpack for refills in the field. This would basicly be an in-line version of my mortars.

Even simpler (and cheaper) would be a pressure chamber with a shrader (aka bike tire valve) feed in the back and you could fill the pressure chamber with a bike pump.

[Nikpo]

Simpler would would be nice. I don't need to field-reload this thing, since it is meant to be a "disposable" rocket launcher anyway.

Could you go into more detail on that last idea? How would I assemble the trigger for the pressure chamber to release into the firing chamber, and what do I need to buy?

[Timebomb757]

[QUOTE=venom;25256207]
Could you go into more detail on that last idea? How would I assemble the trigger for the pressure chamber to release into the firing chamber, and what do I need to buy?[/QUOTE]

Depends on how you want it to be fired, how much money you are willing to spend on a trigger mech, and how mechanically inclined you are.

The simplest would be a ball valve, IE:
[img]http://www.airlink-compressors.co.uk/images/locking_lever_ball_valve.jpg[/img]

If positioned properly, these are a plenty effective way of dumping the air from the chamber into the barrel. Sometimes they require a bit of force to open though, and this can throw accuracy off, and in extreme cases (IE: a stick valve and a ton of pressure behind it) even make it impossible to shoulder fire (Ive had to use a wrench to get them open in the past) They take the longest to open, and therefore dont perform as well (Read: only shoot kind of ridiculously far). They are also the cheapest method.

A good example of a launcher with a ball valve:
[img_thumb]http://www.milsimlabs.com/mortarround%20001.jpg[/img_thumb]

I can go into other methods if you wish, but they are a bit more complicated and a good bit more expensive ($40+)

[Nikpo]

I'm willing to spend the extra $40 if it means it'll be easy(er) to trigger than a ball valve.

[lorden]

[QUOTE=venom;25260155]I'm willing to spend the extra $40 if it means it'll be easy(er) to trigger than a ball valve.[/QUOTE]

I dunno, the launcher he showed a picture of would realistically only cost about $10 for bulk tubing, a one-way tire nipple, and the ball valve. If you're going for cheap and disposable, a launcher like that sounds perfect. The projectile sounds like the hard part though, I guess if you're going for cheap a large amount of BBs with some kind of wadding to keep it in would work as a massive shotgun, a nerf rocket seems kind of silly unless you're going for a direct impact shot though.

[L_Dawg]

Or if you're aiming that rocket at vehicles.

[Nikpo]

~bump~

I think I've decided I want to run this using a 40mm grenade, just for the sake of simplicity.

What would be the best way to do this? Get a madbull 40mm launcher or something and just build around that?

[CodeMonkey3]

Buy a deactivated AT-4, build with that.

[Capn'Underpants]

I actualy have plans drawn out for a nice rocket launcher.
If I get the time and cash I could build it and get a tutorial done, though it'll cost alot.
Grenades to be bought, PVC tube, green gas, firing mechanism construction and material, pistol grip and such.

[Taepodong-2]

[QUOTE=CodeMonkey3;26656977]Buy a deactivated AT-4, build with that.[/QUOTE]

Where is he going to get a deactivated AT4 in Canada?

[CodeMonkey3]

Wal-Mart.

[Nikpo]

Well I want to build an RPG-26, so an M136 isn't going to help much.

[RenegadeSanta]

So you've decided to use 40mms? Also is it being disposable a big deal for you? If not, get a madbull launcher and build around that. It'll be like a HERA kit but for a rocket launcher and cooler.

[Nikpo]

Disposable? I mean, I'd most likely like to drop it after firing it if it's a smaller skirmish, but I'd like to pick it back up and re-use it afterwards. I don't need it to be field-reloaded though.

[Stupideye]

make a rpg-7 instead