16 replies to this topic

[Buffdaddy]

Sadly, I keep getting sidetracked from my semiauto design by neat/crazy ideas. This is one of them.

Yes, we're making a mortar for launching dart across a field of play. Obviously, this has little offensive use, unless it's a small field, or it's objective based and people are pinned down enough to use it as a clearing device. Defensively, however....it could be useful. Shoot spreads of darts over cover, for example. Rate of fire is automatically horrible, but who cares? IT'S A MORTAR.

Construction pics follow. No much instruction is needed, should be self-explanatory.

Main body of the mortar. 2" PVC, with couplers down the whole length. Just for my safety, I want as much PVC lining it as possible.


Presta valve, jb-welded into place. Tee for an OPV.


Bottom of the mortar. Shaved down the insides of 3/4" to 2" bushings, slipped in pipe, and capped off to keep it sealed. You'll see my reasoning in a sec.


The whole shebang! OPV in place, and with base for support.


Multiple slots underneath the body


Used snap-on tees to allow movement of the support arm (with some effort, of course).

Testing commences tomorrow, when hopefully it stops raining.

I will be using a foot pump with this, as (besides a compressor *cough*cheat*cough*) it is the only way to really make it war-worthy. Wouldn't you want to be able to shoot back while you're priming this thing?

Also, there will be a longer handle on the valve, to make opening it easier.

AS SUGGESTED: A sprinkler valve would be more effective, but I really don't give a shit. This is for the lulz, after all.

Edited by Buffdaddy, 23 July 2011 - 11:59 PM.

[psychoswan]

How does loading and firing work exactly?
Is the body an air tank and barrel?
Or are you adding barrels?

Edited by psychoswan, 24 July 2011 - 12:16 AM.

[KoRnEd]

Buff, if this hasn't been said already, you've been on a roll this summer
Nice build, it be fun to convert this to shoot nerf footballs for a wacky game of catch or to rain balls on people from 40 feet away!

[Buffdaddy]

How does loading and firing work exactly?
Is the body an air tank and barrel?
Or are you adding barrels?

The main body is just the air tank; I have a threaded adapter that I'll use for attaching the barrels for various ammo sizes.

Buff, if this hasn't been said already, you've been on a roll this summer
Nice build, it be fun to convert this to shoot nerf footballs for a wacky game of catch or to rain balls on people from 40 feet away!

Yup,this is mainly for crazyness!

[psychoswan]

Oh that makes sense. So I'm guessing some ball barrels and a massive shotgun barrel or two?

[Buffdaddy]

Oh that makes sense. So I'm guessing some ball barrels and a massive shotgun barrel or two?

I'm thinking balls, and stefans/foam rounds from 3/8" all the way to 3".

[evilbunnyo]

Nice. If you keep up these ideas then you pretty much will win the homemade contest by sheer numbers.

So I assume that it is pretty sturdy now for pumping in air but if your still unsure of its saftey why not use some of that instant cement and hold it together?

[Buffdaddy]

I'm pretty sure of the safety. I just decided to overengineer it. A solid piece of 2" PVC would have been just fine.

[Kyrativ]

That's pretty sweet, I'm not sure how war effective it would be but still neat, barrel wise you should absolutely make some nano Stefan shotgun barrels and maybe one for those mini nerf vortex footballs.

[TantumBull]

HAHAHAHAHAHA oh my god this is too funny (read: slightly weird). I literally was just having a discussion with like 3 people at the war yesterday about how much unadulterated fun a nerf mortar would be, and decided to stat building one this week. Couldn't have had better timing, Buff! (that's what she said)

[Buffdaddy]

Nice. If you keep up these ideas then you pretty much will win the homemade contest by sheer numbers.

So I assume that it is pretty sturdy now for pumping in air but if your still unsure of its saftey why not use some of that instant cement and hold it together?

While I'm thinking about it, I've used purple primer and cement on everything. IT WILL HOLD.

HAHAHAHAHAHA oh my god this is too funny (read: slightly weird). I literally was just having a discussion with like 3 people at the war yesterday about how much unadulterated fun a nerf mortar would be, and decided to stat building one this week. Couldn't have had better timing, Buff! (that's what she said)

Well, you'll be pleased to know that, for initial testing with 6" long, 3" stefans (we're gonna have to decide names soon for FBR over 1"....I propose "giga" stefans), my shots were hitting 70' away, with the arc probably going 80-90 feet in the air. Obviously, these things aren't the most aerodynamic. So I'll have to play with weights, barrel length, angle, etc.

I'll get out to test with a more pointy and weighted stefan, and a nano shotgun.

Also, my foot pump is getting about 2psi increase with every stroke. So 50 psi takes 25 pumps, etc. Lots better than I thought.

[Buffdaddy]

Ok, official range tests!

As stated above, the two 3" gigas were hitting 70-80 feet, with the flat faced one going 80-90 feet high, and the one carved to be more aerodynamic twirling around. Given the effects of trying to carve it by hand, I'd stick with keeping it flat for now. Or finding a half-ball to stick on the front.

In any case, I'm guessing that with perfect barrel length/angle/dart weight, probably 90' is the limit for the gigas. But they're so much fun to launch....

I only got one test of the nano shotgun before taking things inside to avoid rain. Results were inconclusive, but promising, as the entire assembly flew 10 feet in front of me. However, of the darts that did fly, I was getting roughly a 10' radius spread at 90'. Will try again later.

Also got a better seal filling the tank; now I'm getting roughly 2.5 psi out of every pump.

I've only been filling to about 50-60 psi for now. More probably wouldn't help the gigas much, but for smaller darts, definitely.

[TantumBull]

Ha, nice. Well I meant more a nerf "mortar" of sorts that would shotgun like 100 to 200 micros

[Buffdaddy]

Ha, nice. Well I meant more a nerf "mortar" of sorts that would shotgun like 100 to 200 micros

Well, I had 35 nanos stuffed in there. I can always build bigger!

[Zorns Lemma]

Something to keep in mind if you make huge shotgun adapters:
More darts per barrel = better shotgun than 1 dart per barrel and cramming more barrels into a shell. The more barrels you have the more routes for pressure to escape before all the darts fire due to difference in friction.


Maybe it doesn't matter for something of this size but it definitely matters on titan/4b shotguns at the 6+ barrel level.

Edited by Zorn's Lemma, 24 July 2011 - 09:36 PM.

[Buffdaddy]

Something to keep in mind if you make huge shotgun adapters:
More darts per better = better shotgun than 1 dart per barrel and cramming more barrels into a shell. The more barrels you have the more routes for pressure to escape before all the darts fire due to difference in friction.


Maybe it doesn't matter for something of this size but it definitely matters on titan/4b shotguns at the 6+ barrel level.

I realized that shortly after making a 19 barrel shotgun on initial construction. Luckily, it was all hot glue, so I could salvage the parts.

The most barrels I'm ever going to have on this thing is 7; I know I've used a 4B with a 7 barrel shotgun, and it performed decently. So I expect better here, esp. with tons of darts in each barrel.

Now to shotgun 1" stefans.....

[The lord of fish]

In my experience with nanos, a good way to shotgun them is to make .5" long nanos, drop in a BB, then glue another .5" inch segment over the BB. They tumble in flight and spread out a little better than a normal nano. Stuff about 10 in each barrel and enjoy.