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Post by ssgjoe on May 2, 2015 22:55:30 GMT -5
Hey guys! So one of my friends a while ago attached a Thunder B to a stick creating a very crude, yet operational, stick grenade. But that got me thinking. I would like to create my own reproduction, plastic headed, CO2 stick grenades similar to a Thunder B. I will be using reproduction stick grenade handles, which I do not know where to acquire (if anyone could help me), and I will be adding a mechanism inside the handle which will puncture a CO2 cartridge to be released into a homemade plastic head and make a loud bang, much like a Thunder B. I already have drafts written for the designs of the contraption inside the handle (attached), and need to create drafts for the head. But I have a few questions. 1) What type of plastic are Thunder Bs made of? 2) Should I be concerned about plastic shards or would those be as dangerous as airsoft BBs or shards from Thunder Bs? 3) If I were concerned about plastic shards, which moldable/castable plastics should I use to make the head? 4) Anyone have ideas for attachment and sealing of the head onto the handle? I have some ideas for the sealant and attachment of the head. I could use rubber cement to make the head airtight, and small hooks to connect the head to the stick so the head doesn't pop off under pressure. I can also make dies out of ceramics for shaping the plastic, the dies will be casted off of a reproduction grenade head. I have looked at some of the liquid plastics. Which one do you guys recommend I use? I want the plastic to be relatively safe, yet sturdy as to make a loud bang when it pops. Actually, any advice you guys have would be great. Has anyone undertaken a project like this? I hope my post was not too difficult to follow. Liquid Plastics www.smooth-on.com/Urethane-Plastic-a/c5/index.htmlDraft Designs www.dropbox.com/s/x69dv4z39z5ykvm/Handle%20design.bmp?dl=0Danke Kameraden!
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Post by hardslack on May 3, 2015 10:28:31 GMT -5
I think you're in uncharted water here. You might focus on the mechanism rather than the plastic shell first. I suspect you'll have a lot on your hands just getting things to work without having to mess with your own plastic shell. You could use thunder b shells until you get the kinks worked out.
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Post by ssgjoe on May 3, 2015 12:56:35 GMT -5
I might test with thunder b shells, however I want to make my grenades accurate; thus the shells need to be a correct shape that thunder Bs aren't.
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Post by ssgjoe on May 3, 2015 12:57:34 GMT -5
I've already got the mechanism figured out. I also got a friend who will help me figure a way to try to modify thunder b cores
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stuka
Sergeant
The one and only
Posts: 1,205
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Post by stuka on May 3, 2015 13:51:36 GMT -5
If you could pull it off with type97 grenades that'd be pretty awesome but they are smaller then other grenades
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Post by ssgjoe on May 3, 2015 14:35:02 GMT -5
Maybe you should take up that project I however hav no need for type 97 grenades.
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Post by insterburger on May 3, 2015 14:45:56 GMT -5
BTW, you're never going to find repro stick grenade handles. You would have to have them custom milled to your specs from wood dowels. Won't be dirt cheap, but if you produce in quantity they might not be crazy pricey, it's a simple enough of a job.
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Post by ssgjoe on May 3, 2015 16:15:36 GMT -5
I was actually directed toward a person that makes repro stick grenade handles. But I'm having trouble getting in contact with him.
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Post by insterburger on May 3, 2015 16:26:39 GMT -5
That's excellent! Sounds like a small custom mill shop, though, which is exactly what I'm talking about. The good news is that if he makes them, he's probably friendly to the hobby, which may help with the price. Keep us posted.
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Post by ssgjoe on May 3, 2015 18:22:27 GMT -5
I will definitely keep this thread updated! Not sure when the while thing will go underway however
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2nd Bat
Master sergeant
Posts: 11,813
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Post by 2nd Bat on May 3, 2015 19:18:00 GMT -5
The challenge (which is not insignificant) is having the tools to create exactly the right thickness from exactly the right vacume formed plastics to withstand significant pressure prior to popping and doing so consistently. If you manage it I will be EXTREMELY EXTREMELY impressed. I wish you well.
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Post by ssgjoe on May 3, 2015 19:33:26 GMT -5
We will have to see how this goes
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2nd Bat
Master sergeant
Posts: 11,813
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Post by 2nd Bat on May 3, 2015 19:38:55 GMT -5
Lots an lots of R&D ahead of you but awesome if you can pull it off. If you can do so affordably there could be a potentially huge market for them.
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Post by cblackthorne on May 3, 2015 19:41:21 GMT -5
How about making the head out of cardboard? Then there is no fear of plastic shards.
-Chris
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Post by ssgjoe on May 3, 2015 20:52:43 GMT -5
I thought about using cardboard, but it's much harder to get airtight and crushed easily. It's definitely not going to be a quick build, lots of designing, prototypes, testing, redesigning, etc until I get a reliable one with a loud bang. I have a way to cast my own dies, and am looking into different liquid plastics for the heads.
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Post by hardslack on May 3, 2015 23:29:26 GMT -5
I just meant build your handle apparatus with he pull string striker and make it work with a standard thunder b shell, before you worry about the correct plastic head which will likely be the easiest part, just a matter of proper plastic and a nice mold. There is a big difference between drawing an idea on paint and having it work. You're also going to have to take the different volume of the German grenade into account. I suspect its about half the size of the smallest thunder b shell, so if you use the same co2 cartridge your timer will likely be half as long.
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Post by ssgjoe on May 4, 2015 8:37:25 GMT -5
I was planning on practicing with a standard shell now that I know how to modify an existing thunder B core. As long as the wait time is a round 5 seconds like German grenade, then that works. And the stick grenade head is wider than most Thunder B shells, so it adds some volume to it.
My main issue with the head is actually finding a plastic that will hold air pretty well, but won't explode into a bunch of shards. Thunder B shells are made of ABS plastic; if I could find a way to use to ABS plastic, then I'm golden. However ABS isn't a resin. Not sure if there are any liquid plastics that will harden into ABS plastic
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Post by ssgjoe on May 4, 2015 10:01:41 GMT -5
So I just talked with someone who can make reproduction stick grenade handles, which costs less than $10 per handle for him. Not sure how much he'll mark up
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Post by ssgjoe on May 4, 2015 10:44:19 GMT -5
After looking around, I found a source with both flexible and semi rigid resin. Should I use the flexible or semi rigid resin for the head? I'm afraid about the semi rigid resin splintering upon explosion.
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Post by aldrich on May 4, 2015 11:22:07 GMT -5
Explosives will take the path of least resistance when exiting an enclosure. If you placed a seam or weak point in the head, it should rupture at that point without exploding out equally in all directions causing fragmentation. As far as the resin goes, you want a bit of a flex. If it is too hard it will become brittle and be more likely to shatter than to rupture.
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Post by ssgjoe on May 4, 2015 12:17:10 GMT -5
The semi rigid bends and flexes. The flexible resin is kinda like rubber. I was thinking about just using a seam as the weak point. If the seam isn't weak enough, I'll apply a heat gun to some areas.
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Post by aldrich on May 4, 2015 13:00:28 GMT -5
I would go with the semi ridgid resin. The rubber like material will likely be too soft.
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Post by ssgjoe on May 4, 2015 14:32:27 GMT -5
Sounds good. I think I'll go with that. Say, what's the diameter of a still grenade handle at it's thickest point and it's narrowest point? I do not own my own stick grenade to measure myself.
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Post by insterburger on May 4, 2015 14:55:33 GMT -5
My replica measure 39mm at the thickest point and 31mm at the thinnest.
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Post by ssgjoe on May 4, 2015 15:16:53 GMT -5
So that's almost two inches at the thickest and a little kvetch an inch and a half at the thinnest.
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Post by ssgjoe on May 4, 2015 15:17:00 GMT -5
Thanks!
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