45 replies to this topic

[CaptainSlug]

The other grenade topic made me rethink my older grenade designs and I came up with something rather simplistic to make. It only requires drilling some exacting holes and have the needed hardware on hand.
The darts (somewhere between 24 and 32 of them) are loaded against a set of rubber-bands that should be able to shoot them outwards 10-25 feet. Thus giving you an effect radius of 20-50 feet.

It's made out of the spindle packaging that CD-R/RW & DVD-R/RWs come in, but the design will only work with taller stacks that have the space needed to orient the darts sideways. A decent amount of space is needed for the spring and the travel length needed for the shell to be moved 3 inches. It works in either direction and if desired you could load darts into only one side for a directional mine.


The AR-15 spring is powerful enough to launch either half of the spindle 3 feet into the air, so it will be perfect for over-coming the friction that all the darts will be adding to the inside. For safety's sake the threaded rod will have a nut on the end that will keep the two halves from coming apart when triggered.

Two triggering mechanisms are possible. The packaging itself includes locking teeth that act as a safety mechanism and that could be undone almost all the way and any disturbing of the mine will set it off. However I'm going to make a center rod to replace the threaded rod that will have a quick-release pin on the end that you can pull out from a string that will set off the spring.

Right now I'm just waiting for supplies to come in the mail. I've already drilled all the holes I need so once I have this tested and tweaked I'll post a construction write-up and video.

(assumed) Supplies needed
+ Packaging from a 100 pack of writable CDs or DVDs
+ Eight 3-inch or 4-inch length UNC #8-32 threaded rods (mcmaster part# 95475A338)
+ A Bunch of 1/4" length #8 nylon spacers (mcmaster part# 94639A401)
+ A Bunch of #8 steel washers
+ #8-32 hex nuts (mcmaster part# 94812A114)
+ AR-15 Carbine spring (or decent substitute because anything with the right compression rate that will fit over the spindle will work fine)
+ Two junked CDs or DVDs that you can drill 8 holes in
+ A 1lb Bag of 3-1/2" Lg X 1/4" Wd, Size 64 Rubber bands (mcmaster part# 12205T55)
+ 24-32 2-inch length stefans
+ 1/2" OD aluminum or plastic rod (not sure what length yet)
+ some #6-32 screws
+ PETG Clear Tube 5/16" OD, 3/16" ID (mcmaster part# 9245K15)

Edited by CaptainSlug, 19 February 2007 - 08:31 PM.

[nerfer34]

YES! I have been waiting for you to come up with a grenade!

This is awesome!

That's wied, I had an idea very similar to this today except mine was air-powered.

I am REALLY looking forward to this!

Edited by nerfer34, 19 February 2007 - 05:46 PM.

[Retiate]

That's a really good idea. Though why do you need a spring that powerful? Isn't that the same spring Boltsniper uses for his homemades? Or is this one a lot weaker?

It would be really easy to make this fire when a wire is tripped. Just wrap some string around it, then pull it tight across a doorway or whatever you want. The string gets pulled, the top gets unscrewed, and darts fly everywhere.

[CaptainSlug]

That's a really good idea. Though why do you need a spring that powerful? Isn't that the same spring Boltsniper uses for his homemades? Or is this one a lot weaker?

It would be really easy to make this fire when a wire is tripped. Just wrap some string around it, then pull it tight across a doorway or whatever you want. The string gets pulled, the top gets unscrewed, and darts fly everywhere.

Yes it is.
I want the option of an air-burst and the spring is powerful enough (even in short lengths) to shoot this atleast 2 feet into the air when loaded with darts. The spring also has to overcome a good deal of friction so the stronger the better. If you want the spring to be a bit weaker you can simply cut it to a shorter length.

The finished mine will probably be oriented like so.

Removing the washer at the end of the center rod will allow the spring to shoot the mine 2-3 feet into the air. Leaving it there will keep the unit together (much safer).
The hole in the rod is a cotter/linch pin trigger release.

A 4-inch threaded rod could be used in place of the rod if the lock mechanism were to be used at the trigger. Then simply covering the whole thing in dense foam might make it safe enough to throw.

Edited by CaptainSlug, 19 February 2007 - 06:30 PM.

[nerfer34]

Won't the rubber bands detoriate in that position, especially if left like that?

Can you explain how the spring is going to trigger the rubber bands?

Thanks

Edited by nerfer34, 19 February 2007 - 06:46 PM.

[Prometheus]

The spring removes the clear top, which holds the stefans in place. When the top is removed, the elastics (which have been stretched to that position) unstretch, thus rocketing stefans everywhere.

[Carbon]

I don't necessarily care for grenades, but that's pretty cool.

What method do you have in mind to load it? That's a lot of tension over 360 degrees to keep in check until it gets locked down.

[TT]

That is probably one of the most simplistic yet mind blowing designs period.

[CaptainSlug]

Won't the rubber bands detoriate in that position, especially if left like that?

Rubber bands do have a limited usable life span, but they're dirt cheap and perfect for this application. They won't be interacting with any rough surfaces so wear will only be the result of them drying out from aging. If you buy the rubber bands I designed this around you'll have 480 spares.

What method do you have in mind to load it?

That's the only thing I haven't figured out completely. If it proves problematic I'll drill some holes in the base that I can insert screws through to hold the rubber bands back until the unit is primed.
This is the kind of feedback I like. I know have another idea to work with.

Edited by CaptainSlug, 19 February 2007 - 08:10 PM.

[TT]

Won't the rubber bands detoriate in that position, especially if left like that?

Can you explain how the spring is going to trigger the rubber bands?

Thanks

You can always get another rubberband, so I don't think it'd end up being a major issue.

Edit: Scratch that.

Edited by //T\\, 19 February 2007 - 07:53 PM.

[CaptainSlug]

To address what Carbon brought up I will have to drill a bunch more holes. And then I will lace these 2-inch tubes to the middle of each rubber band section. To prime each "wedge" of the mine you push the tube towards the center then insert a threaded rod through the spindle base, the tube, and both CDs.

This locks the rubber band in place so that you have a much easier time refilling the whole thing together.
To keep the tubes from being shot out with the darts they'll have to be tied to the rubber bands with some string.

Once the whole unit is locked together you arm the rubber bands by pulling the threaded rods out. The darts will then become wedged against the inside of the shell. Even cooler is that a smaller parachute triggered version of this unit is now possible thanks to this change. I'll get on that later.

Edited by CaptainSlug, 19 February 2007 - 09:06 PM.

[Grenado]

Crap, that's awesome. It brings a whole new aspect in to CTF. It might be better if you used 1 or 1.5" darts.

[CaptainSlug]

Crap, that's awesome. It brings a whole new aspect in to CTF. It might be better if you used 1 or 1.5" darts.

Dart size is really up to you when it's made. All you will have to do is use fewer spacers.
It will make more sense once I get the prototype made.

I've also been thinking that since this design is triggered by a pin that a timer relay with a solenoid could be setup to turn this device into a time bomb.
Something like this would work fine.
http://www.electroni...elec/ck1604.htm

Edited by CaptainSlug, 19 February 2007 - 09:11 PM.

[nerfer34]

That trigger circuit is so awesome!

I wish I was mechanical enough to install that into something cool.

[KBarker]

You could also wire up the solenoid to the guts of a cheap RC car, then you could trigger it manually from 40 feet away when someone walks by. Awesome grenade!

Edited by KBarker, 19 February 2007 - 11:46 PM.

[Skitzo]

The other grenade topic made me rethink my older grenade designs and I came up with something rather simplistic to make.

Wow Im really glad that I could spur your interest in making this grenade all of a sudden.
I have one of those cd holders so I will try this shortly and attempt to contribute to this awesome grenade.
Where my grenade is more of a novelty I think this could be more functional in a war because it wont get broken as easily and can be set as a trap.
But it seems that this might take a while to load compared to mine and size might be an issue but other wise this is awesome.

-Skitzo

Edited by Skitzo, 20 February 2007 - 08:53 PM.

[TT]

So, I just recently did a few small scale test runs [with a 15CD case and NF spring] to see how easily this could be triggered by just throwing it. It works beautifully. Just turn the cover enough so that it is hanging off about halfway and toss. Can't wait for you to make a real one CS.

Edited by //T\\, 20 February 2007 - 10:16 PM.

[Cmdrmack]

Would it be feasible to have a set of pre-loaded bases to decrease priming time? And would CD's or some other disk of comparable size but more study construction work to make almost interchangeable cartridges for this thing?

[CaptainSlug]

Would it be feasible to have a set of pre-loaded bases to decrease priming time? And would CD's or some other disk of comparable size but more study construction work to make almost interchangeable cartridges for this thing?

There might be a way to do that by having the CD sandwich attach to the base using velcro.

[Prometheus]

Would it be feasible to have a set of pre-loaded bases to decrease priming time? And would CD's or some other disk of comparable size but more study construction work to make almost interchangeable cartridges for this thing?

If you have all the pre-loaded bases already, it would only take a little more work and parts to make a few more complete grenades. Then you don't have to go back searching for pieces of the original, and you would have better odds of a hit with the extra grenades planted.

[AssassinNF]

I've been making alot of different grenades lately. Barricade Busters are my favorite so far, because of the great spread they have. I've made my own variation of the Schitzo Grenade that shoots three darts and is made of solid foam instead of cardboard, and It works great, but I can't seem to hit anything with it. The three darts shoot a perfect triangle around the person I try to hit, so I need to make some larger Schitzo's with a higher capacity, like the 15 dart ones.

Now we have CaptainSlug's idea, which reminds me more of a land mine than a grenade. I love the design, but it looks very complicated to make, so I hope CS is considering selling these if they turn out to be very easy for him to mass-produce. I'm currently working on my own variation of this design that is one-directional, like a claymore, and I'll see if I can get it to work.

I can't wait 'til you get a working prototype made. Good Luck!

[CaptainSlug]

I don't know how I would be able to mass-produce these at a reasonable price unless I can find a source for outdated slow CD-Rs in bulk so I can use the packaging.

Now we have CaptainSlug's idea, which reminds me more of a land mine than a grenade.

And that was the intent. I really wouldn't advise trying to make these throw-able. For throw-ables nothing really beats barricade busters.

I now have all the supplies but have more pressing tasks to complete. I will get back to this next week.

Edited by CaptainSlug, 23 February 2007 - 10:43 PM.

[nerfer34]

Now we have CaptainSlug's idea, which reminds me more of a land mine than a grenade.

And that was the intent. I really wouldn't advise trying to make these throw-able. For throw-ables nothing really beats barricade busters.

I now have all the supplies but have more pressing tasks to complete. I will get back to this next week.

Really?

O yea you sold me some foldable frisbees to make barricade busters a while ago....

I still can't get them to work. Mine get a spread of under a foot!

[CaptainSlug]

O yea you sold me some foldable frisbees to make barricade busters a while ago....
I still can't get them to work. Mine get a spread of under a foot!

*sigh
I'll make you an instructional video tomorrow.

[nerfer34]

Thank you that would be great.

I have literally spent an hour trying to get these working last night after I posted and don't see how this thing can propell darts 25'+....