75 replies to this topic

[Carbon]

That is one of the few Nerf guns I like the black paintjob on. Good job. I also like the fake clip, but just out of curiosity why didn't you put it directly left if you're going for the sten look?

The fake clip is also gonna be used for dart storage. Since I fire with the left and load with the right, it made the most sense. It's enough to imply Sten, at least. But you're right, if I was directly modeling a Sten, it would be on the left.

[davidbowie]

I think i'm also about to start on something like this. It will be slightly different, with a breech loading jumbo barrel, a thompson-style foregrip, and a stock with the plunger pull inside it, like on the crossbow.

[Carbon]

Sounds like you're describing where I want this design to eventually head. I'm working on the SNAP-2, and it's similar - bolt action plunger, and the rod draws back into a stock. Similar shape to what I have here, and I'll use the clothespin trigger again. Eventually, I'm going to add a clip, but I haven't decided on the full mechanics of that yet...Ompa's system would add in well, and I'm also tossing around an idea of using a cartridge based system, but using Crayolas. I'll be interested in seeing how you approach it, DB....

Edited by Carbon, 02 February 2006 - 10:51 PM.

[davidbowie]

I'm not going to include a clip on it, at least not yet. I'm still tweaking my first clip feed, so this gun is going to have to be simple. I might consider a turret, though.

Here are my ideas:

First Possibility:


Stock, no foregrip. Breech barrel.

Second Possibility:


Foregrip, no stock. Also breech barrel.

The breech is simply a sliding cover over the pipe. I already have the barrel made, and it has a 1/2" male adapter on the end, meaning the gun will be able to use different barrels for different ammo.

[Carbon]

Nice stock modeling on that one...sort of like a crossbow. I'm using a little bit different tack...



I found that by using the same bushing at the rear, I can easily remove the spring, and keep it in place with 1/2" PVC (which can also serve as a stock). The spring pole runs into it.

I'm trying out an action lever directly attached to the plunger. I have yet to do the gasket addition to the plunger head, so I don't know if the additional weight of the plunger weight and the handle (as well as that huge slot!) is gonna kill my range.

Speaking of ranges, I brassed the SNAP-1.



Dremel-ed out 1/2" PVC, drilled through both PVC and brass, slipped in a cotter pin, then glued the holes. It's airtight, and I can make barrels of any size, for whatever FBR I happen to find (like what you said, DB).

I have roll of 5/8" FBR that seems *huge*....fits way too tight in 1/2" PVC...but I decided that it'd be easier to build a barrel for it than searching for smaller FBR. Turns out that it needed 21/32" pipe. 11/16" would be even better (vacuum load *still* doesn't work, gotta ramrod), but K&S doesn't go that big. I made 1.5" stefans with two split shots. Yields about 45'. I don't mind about the reduced range, as these darts pack a punch...

Still not sure about my barrel length...although, I came up with another way to test it (sorry if this is a crazy-shit idea, but it seems viable);

1) Fill a bucket or bathtub with water.
2) Put a container of known voulme in the water (like a cylinder), fill it up, then flip it over, so the bottom is up.
3) Place the barrel of the gun under the edge of the container, and fire. This should fire air into the container.
4) Lift up the container so that the level of the water in the container equals the level in the bucket/bathtub. This is the plunger displacement.
5) By measuring how much lower the water is in the container, you can calculate actual plunger displacement volume, rather than figuring plunger volume (which doesn't account for leaks).
6) Plunger displacement should equal barrel volume. Diameter is a known, so solve for length.

I'll be testing this tonight.

Edited by Carbon, 19 April 2015 - 04:18 PM.

[davidbowie]

WHOA!

What if you made the Grip the plunger tube?

This would make a great SNAP pistol.

The clothespin would line up with your finger in its natural position, for a decent trigger.

Yet another thing to put on the To Do list.

[Super 6 0ne]

I like where you're going with this.

[Ronster]

Looks good.

I just have one question about the Snap 2.
Wouldn't you lose alot of air from the hole drilled in the side for the charging handle?

[Deaths Avatar]

If his plunger is long enough, than the head with the seal/o-rings will never come all the way back to the slot for the handle, and there would be no air loss.

-DA

[Carbon]

If his plunger is long enough, than the head with the seal/o-rings will never come all the way back to the slot for the handle, and there would be no air loss.

Exactly. I had to measure out the length of my plunger draw, then make sure that my plunger was that long. The plunger gasket starts just ahead of that slot. The downside of that is the plunger is about twice as long as the SNAP-1. I'm thinking about swiss-cheese-ing it to save some weight...holes would reduce weight, but shouldn't compromise the strength. I got it gasket-ed last night, added a handle, and gave it a SNAP-1 stye trigger. Ranges and power appear to be the same.



Davidbowie - That, dear sir, is a freakin' brilliant idea! 3/4" PVC for the handle, 45 degree bend at the top, 3/4" to 1/2" converter for the barrel. I'll have to check my parts bin and see if I can whip one up....

Thanks, Super 6...yeah, I'm taking baby-steps towards the functionality of a FAR, in a simpler manner. I'm building the two, but the systems for the SNAP-3 are floating through my head.

I've been checking out the work you've done on your prototype as well...really interested to see when you start to get your sample made, and how your systems work. You got some great ideas going with it.

Edited by Carbon, 19 April 2015 - 04:18 PM.

[Super 6 0ne]

You oughta paint the SNAP-2 gunmetal grey, to mimic a sten gun even more. Besides, you've already got a black gun.

Once again, great work. It all looks very clean and professional.

[SolidiusSaint]

So what is the accurate range on this weapon? Looks really good just need s nice paint job

[Carbon]

So what is the accurate range on this weapon?

I haven't done any measured tests yet...just got the trigger functional, and it's been seriously windy here lately, but my casual indoor tests have it behaving identially to the SNAP-1 with a micro sonic...which means probably 55-65 foot ranges, flat. I'd guess a little less due to heavier plunger.

I need to get some additional stuff onto it (trigger cover, foregrip, and yes, this one needs sights), and then I'll get 'er painted. Gunmetal grey, nice idea S6O. I'll see what I can find.

[SolidiusSaint]

Sounds sweet! you should get a video of this new weapon and post it in the Homemade section.

[davidbowie]

Well... I got the main body of mine done today. The big obstacle now is to find springs for it. I was thinking of using surgical tubing, but then there would be lots of impact on the reducer to the barrel, because the tubing would keep pulling until it hit something.

My plunger is a chunk of 1" pipe with an o-ring groove filed in it, the threads from a 3/4" male adapter epoxied inside the pipe, and a broomstick epoxied inside those. It actually works!

How strong were the springs you used, carbon? Do you know the strength in lbs? Even a rough estimate? All I could find at home depot was either way too strong (30lbs) or really weak (1 or 2 lbs)

[Super 6 0ne]

I'm slowly falling in love with this thread and the way you think, Carbon. I love how incremental and hands-on your work is. There's no bullshit in your designs. Just gun.

So I thought I'd post some pics of the aforementioned WWII SMGs for visual comparison, and maybe to generate some ideas.

The Sten gun:


The inside of a Sten:


If you think anything like me Carbon, and I think you do, a magazine-fed SNAP will look a lot like the above. Not bad.

Here's a good picture of a Sterling:


Those vents are pretty slick. Maybe you could sheath the exposed part of the barrel of your SNAP with a larger diameter piece of CPVC and drill a bunch of holes in it. It'd be purely superficial but hey, sexy is sexy.

And the abominable Grease Gun:


Did you guys know that the US military used these suckers all the way until the Gulf War? Impressive.

That's a good pic, too. If you paint a SNAP gunmetal grey and still aren't satisfied, try to replicate that sweet battle-hardened patina the Greaser in the picture has.

Anyway, once again keep up the good work Carbon. I love reading about your progress.

[Carbon]

Looking forward to seeing your plunger, DB...I wasn't sure how to use the whole 1 inch nesting inside 1.25" possibility, without using fittings.

As far as my spring, try a hardware store, as opposed to a home improvement store...I found mine in the area with all the drawers of individual screws and such. I found the ones I'm using at Farm and Fleet, individually packaged. No pound rating, but the package has some info on it: "Handi Pack part # 88043, 11/16" x 9 1/2", .072 wire diameter compression spring". I've also found nearly the identical spring at True Value Hardware, in the same area (the little drawers), just not packaged.

Just to let you know, my reducer is taking the entire force of my plunger. It's also why I peppered it with 8 screws around the diameter.

Great pics, Super 6, and we're definitely thinking alike...I've been looking at ompa's and Renegade's breech feed clip mods, and they'd both integrate very nicely right at the barrel. And you're spot on with the "grease gun" comparison as well, fow what I'm trying for...simple, effective, and not exactly attractive. Well, I'm not trying for unattractive...

Nice idea with the Sterling. It's a good shape to emulate, and is pretty close to what I have now. And hey, I'm not above adding a touch of sexy cosmetic goodness.

Thanks for the kind words and the encouragement...I''ve gotten a lot out of this thread, and I'm really looking forward to see where people take this design.

Edited by Carbon, 05 February 2006 - 09:23 PM.

[davidbowie]

OK, so here's what I have so far:



Sorry for the horrible pic, but you get the idea.

It's a really nice size from what I can tell so far.

Here's the breech:
Closed
Open

And here's how I did the plunger:
Plunger

To seal the gap between the 1" PVC and the broomstick, I cut the threads off of a 1/2" socket X 3/4" NPT adapter (that thing on the muzzle of the FAR) and jammed it in there with epoxy. That handy little o-ring came off of the plunger of a 3/4" repair coupling, and it's just what I need. The cool thing is, the repair coupling still works great without it, so i'm not paying 3 bucks for an o-ring.

I'm feeling pretty comfortable with the trigger mechanism. I've already build a popcorn shooter with the same setup, and it works fine.

[Carbon]

Cool, now it's just a matter of finding a spring to deal with the broom handle.....I hope it isn't too big (or heavy) for the springs you find. Cool breech work, too....

Well, you had to go and say it, so now it exists: the Simplified Nerf Armorment Prototype - Sidearm, or SNAP-S. Or, just call it a SNAPgun.




Like you suggested, DB, the handle is the plunger.



And yes, it's small. Here's a size comparison:



Range appears to be about 35 feet. (I'm using one of the two original SNAP-1 springs, so it's a little weak.)

The plunger casing is made out of 3/4" PVC. Rod is a 1/2" dowel. The catchring is a 1/4" ring of CPVC sanded to fint inside of 1/2" sched 40, and pinned with a finishing nail, sanded flush. I tried making the piston head out of e-tape, but it kept working its way off after 10 shots or so, so I cut a gasket down to size and screwed it to the top of the rod. If I was doing it right, I would have capped it with a washer, but I didn;t have any that size...so, hot glue it is.

Top tube is 1/2" PVC, Crayola, and a bushing or two to get it down to 3/4"

The downside? This thing is freakin' ugly.

Edited by Carbon, 19 April 2015 - 04:19 PM.

[AirApache]

Impressive, Carbon.

If you're looking at the aesthetics for the SNAP-S (which I think is hardly of concern), if you're looking for the pistol look, then I'd suggest making the PVC connector a 90 degree angle one. If you really want the slightly diagonal handle look, you can add extra wood/PVC (and perhaps concealing the trigger at the same time).

Personally, when I hear sidearm I think of the NF or scout design which is that the plunger and handle are separate, but you wanted one that's combined, so I guess the SNAP-S does a pretty good job of that.

35 feet is pretty impressive. Just by the look of the size of the plunger, I don't think it would hurt to have a longer barrel.

Air

[Carbon]

I suppose, how it looks really isn't that important. I think I'm just hoping to keep it from looking like a flashlight. And you're right, adding the trigger cover is needed (it'll help keep the firing pin from being accidentally pulled out, too.) I'll try a longer barrel, too, as well as fixing my gasket (part of it is flipping down, instead of pushing forward.)

The plunger/handle synthesis solved a problem in the "handle attached to plunger" scenario - namely, having to fabricate something to pull the firing pin. Having the plunger up top would definitely follow the typical body shape, but I can't think of a simple triggering assembly - at least, not right now. Bolt's GNS has a beautiful solution, but it doesn't fit in with the "quick and dirty" way I've been approaching the SNAPs. I really need to go and study his design, see if I can adapt it somehow.

EDIT: a potential solution to needing a smaller triggering solution for a pistol might be "mini" clothespins. Looks like you can buy them at craft stores, and they range from an inch to an inch and a half - which means the important spring area might be only 1/2" to 3/4" of an inch long!

Google is my friend: Michaels sells 1" long pins, $1.84 for 50. I'll pick some up and see what can happen.

[davidbowie]

Also consider chip clips and memo holders.

Here's my vision of the SNAP-S:


A trigger cover is placed over the clothespin and used to thicken the grip, and a trigger is attached to the clothespin handle. It's made of bondo'ed pipe.

Other than that, the blade sight, the longer barrel, and a a breech, it's the same as your gun.

What the aesthetic is missing is a little bit of top extending past the handgrip. This shouldn't be too hard to do, maybe using a wye and plug instead of an elbow.

MY SNAP UPDATE:

First off, I solved all of my spring woes. My plunger tube is bigger than yours, plus the shaft is a broomstick. I would have needed a foot of spring. That just wasn't going to happen. Instead, I decided on surgical tubing. It works beautifully.

I bolted in the reducer. I used 6 sheet metal screws and two eye-loops (to attach tubing). It's quite sturdy, but I still want to put in a bumper to keep it and the plunger from getting damaged.

The charging handle is a tee, which I am going to cut down to a simple loop, like on a NF.

The O-ring provides a great seal.

I can tell this thing is going to be powerful! I've been getting ranges of 15-20 feet with NO BARREL. Simply pushing the back of my jumbos into the 1/2" female threads on the reducer provides about 1/2" of barrel, which produces a decent shot surprisingly.

I discovered I will need a 3/4" barrel rather than the 1/2" thinwall I had planned on.

The trigger and grip still need to be done, plus the stock.

[Super 6 0ne]

That's awesome DB, I can't wait to see how it turns out.

And I really like your take on the SNAP-S. I'll bet with a couple of minor modifications, you could turn that into a pretty sweet scatter gun.

And what better secondary weapon is there than a scatter gun?

[Ronster]

What's a scatter gun?

[euphemism]

Scattergun traditionally means shotgun, I'm not sure whether or not that's what super61 means.