17 replies to this topic

[nimane9]

I've seen many attempts at creating an under barrel grenade launcher. Well my design starts with a story, I was having one of those ice cream push ups, and when I saw the pushy-thingy I thought "That would fit perfectly in 1-1/2" PVC" So I got home and it fit, I looked up at what size PVC "Ballistic Balls" fit best in. 1-1/2" PVC! So from there one I sacrificed a Strike-Fire and got the spring out since I don't wanna order any [k26] springs for now I put the Strike-Fire spring in. Basically I've got about 6 inches of PVC with a custom fit end cap in the end with a hole in it. For the plunger head that's the push-pop pushy-thingy. By screw the plunger head is attached to a dowel attached to a t-connecter. The t-connecter is outside the whole assembly and when you pull back it primes the launcher. Since I'm too lazy to make a trigger for now I'll just have a removable pin that goes in front of the plunger head.
Questions? Comments? Flames?
P.S. Pictures will be posting in the next few hours.

EDIT I got a longsrike spring in, but the screw popped out so gotta glue it in.
EDIT If this design doesn't work I'll make an actual air seal

Edited by nimane9, 22 May 2011 - 10:34 PM.

[Y-Brik]

Cool story bro. FYI, we like pics over a wall of text.
EDIT: missed the 'PS'

Edited by Y-Brik, 22 May 2011 - 09:29 PM.

[andtheherois]

So basically you pull back the primin bar then the plunger head pushes the ball forward?

[nimane9]

[nimane9]

So basically you pull back the primin bar then the plunger head pushes the ball forward?

You pull the priming handle back which compresses the spring and release to fire.

[Kid Flash]

I'd have to recommend a piece of CPVC with an end cap for a replacement of the wooden dowel. From there you can use a bolt coming out the front (similar to a snap plunger head) and have it go through whatever that ring of your is. That might help with what you said was breaking. Eventually the wooden dowel will strip.

[nimane9]

I'd have to recommend a piece of CPVC with an end cap for a replacement of the wooden dowel. From there you can use a bolt coming out the front (similar to a snap plunger head) and have it go through whatever that ring of your is. That might help with what you said was breaking. Eventually the wooden dowel will strip.

Do they make quarter inch PVC, or if they don't should I use half inch?

[HasreadCoC]

Do they make quarter inch PVC, or if they don't should I use half inch?

Use half inch, 1/4" if you can even find it would be too weak.

[andtheherois]

Interesting design. It reminds me of the xploders line of guns. You might want to find some way of rigging up a trigger for that thing though. I don't think I've seen another blaster that shoots it's ammo using only the force of the spring, rather than the air generated by it. Maybe you could replace that flat plunger head with a concave endcap so that the ball sits inside of it?

[Kid Flash]

Do they make quarter inch PVC, or if they don't should I use half inch?

Well, for the CPVC, I'd say 1/2 inch... I don't know why you would use pvc. It would slow down the plunger rod, if you want to call it that.

[nimane9]

Does anyone thing I'd get at least 20 feet with an air seal from a rubber washer?

[andtheherois]

Does anyone thing I'd get at least 20 feet with an air seal from a rubber washer?

Correct me if I'm wrong, but your ball is pushed by the spring. If that's the case then How far your ball will go will depend on force of the spring, not the air seal, because there's no actual pressure chamber.

[nimane9]

quote name='andtheherois' timestamp='1306191590' post='298452']
Correct me if I'm wrong, but your ball is pushed by the spring. If that's the case then How far your ball will go will depend on force of the spring, not the air seal, because there's no actual pressure chamber.
[/quote]
You are correct, but I was thinking of using a rubber washer to create a plunger head thingy.

[Buffdaddy]

If we're talking about launching based purely on spring power, then this type of setup does exist:

Air Zone Rocket

You can find smaller toys in Walgreen's/CVS or Big Lots, with foam planes that launch by the same mechanism. Very little modding potential on any of them, but who knows, someone might get creative. I've wondered if you could get a plunger head of sorts in place of that missile...but that would be a pain in the ass to balance a nice seal and getting it to actually move.

[nimane9]

Based on my current feedback I'll stay with the propulsion method of being pushed by an actual spring, but if anyone has a better idea for propulsion at a level so compact I'm open for suggestions. Also, does anyone thing a clothespin trigger would work?

[durka durka]

Being that you're building this to be mounted under a blaster, it would be simple to design a latch of some sort that would grab the end of the plunger rod when it was pulled all the way back. I would think this would be a better alternative than to put the all the strain on a wooden dowel with a traditional catch, especially with a system that relies directly on the strength of the spring.

[Exo]

I bought a semi-auto pistol version of this at dollar tree, and it gets maybe 7 feet flat, usually like 5. I made some grenades using 3/4" foam pipe insulation, hot-gluedcardboard to the front, ductaped over the cardboard, and with a 1 1/2 inch wide barrel, a BBBB pumped till OPRV'ed, gets about 20', is fairly accurate, but not entirely reliable, because they misfire 1/2 of the time.

[shardbearer]

Nice and simple, I like it.
You could also try firing these to make it a real grenade launcher.

Edited by shardbearer, 31 May 2011 - 06:53 PM.