12 replies to this topic

[Carbon]

I've been enjoying approaching older styles in a smaller form factor. The 3M is a pistol that cocks like a DTG or a Maverick: the charging handle slides back forward, like on the full-sise SNAP-3. Like the 4M, it's made out of 1" thinwall and .5" endcaps.

So, here's the gun:


Zip-ties for the time being, while I'm testing. I'll give it a more permanent assembly later.

It's about the size of a Mav.


I tried a new version of plunger in this blaster. In the past, I've used a compression nut to minimize the size of the plunger head. However, it still limits how small it can be because of how far the stem of the nut extends into the charging rod. So, this time I just cut down the .5" endcaps I was using, to physically make them smaller. The results were pleasing.


A plunger head just as small as a compact plunger, but cheaper and built out of common parts.

Same plunger head as usual:


The plunger is held in the plunger tube with couplers, snugged up with etape. I measured out where to place the endcap and trigger by lining up parts externally and making appropriately. The front coupler has been cut in half. I have a small piece of .5" PVC in the rear coupler to keep the spring in. The screw from the outside of the tube runs through into the coupler and to that piece of .5" PVC. (The retaining piece is glued in, but I wasn't taking any chances).


The chargerod slides backwards, and retracts with an extension spring held under the top .5" thinwall PVC.



The plunger is actuated by screws that go through the charging handle, through slots in the 1" thinwall, and behind a washer held on the charging rod held in place by a screw.


It currently loads with a removable barrel, 17/32" brass, 4" long. Range appears to be about 50'-60', based shorter shots and previous builds (no official ranges yet.) Handle is held on with super glue...that sucker isn't moving, and holds up against the high stress of charging.

Edited by Carbon, 24 February 2008 - 08:56 AM.

[sputnik]

So it is still a regular plunger setup?
Or is it inverted?

[Carbon]

It has a regular plunger setup...pull from the back, air out the front. It just doesn't change total length when it's charged.

[jwasko]

What is the slide made out of? And it's sliding over thin walled 1" PVC, correct?

Also, good job. I am thoroughly enjoying this SNAP-XM line.

Edited by jwasko, 23 February 2008 - 02:46 PM.

[Carbon]

What is the slide made out of? And it's sliding over thin walled 1" PVC, correct?

The slide is carved out of 1.25" PVC. When I was developing it, I was using a piece cut a little more than halfway, but cutting it off gradually gives a better place to grip, and also lets the extension spring be a little shorter. Yup, it's sliding over 1" thinwall.

Also, good job. I am thoroughly enjoying this SNAP-Xm line.

Thanks. I'm enjoying the tubing size switch...it's making me look at things in new ways.

[sam]

Damn, I thought I would be the first to start using 1" thinwall for SNAPs.
This looks pretty sweet. I too am really digging these SNAP-xM line. Did you manage to fix up the SNAP 4M?

[Carbon]

Yeah, work continues on the 4M. Part of it is just improving the tape wrap (I used the same method for the 3M), but also getting the correct barrel length going. Using 4" of brass for this one (as opposed to 6") helped immensely, so I'm going to assume the same for the 4M. They both have approximately the same size spring, and the same draw.

I also haven't given up on using the turret on the 4M....hmm, maybe if I cut down the barrels....

[Bomberman]

Carbs, you are truly the king of homemades! (springers) This is awesome! I would take that as a secondary anyday. Well, my 80' NF still takes the cake, but still, this is awesome. I love the SNAP series.

[sam]

Did you have to round off the back of the catch face end cap? It looks like you didn't, but perhaps the pic is from before pos did that step.

Edited by sam, 23 February 2008 - 05:00 PM.

[Carbon]

Thanks, Bomberman. Yeah, the range is bested by other guns...but if I want 80', I'll use a full-size SNAP. Like you were saying, this is pure secondary.

And yeah, Sam, I rounded off the endcap...I was pretty lax in taking pictures of this gun during assembly. I did some tweaking this afternoon, and took some more with the cowlings off...I'll post those this evening.

Anyway, a few discoveries:

Teflon tape is my new best friend. E-tape may be okay for getting stuff to a close fit, but sliding it in with a snug fit is tough:...my lube tends to make it slide off, it goes in crooked, and can shred if a screw gets hold of it. Teflon tape will compress, not slide off, and makes a great seal. During reassembly, wrap on a few more turns, and the seal is good as new.

I was using the wrong size plunger seal. I was using a step down from the full size SNAP seal, and was getting really erratic results after I tightened down some parts...sometimes 50', sometimes 10, sometimes not leaving the barrel. As it turns out, .5" endcaps are much looser in 1" than .75" are in 1.25", so I wasn't getting a good seal. So, I used a washer from a full-size plunger, and now I get very consistent shots. I fired off a few rounds down my hallway, and I got 50'-55', consistently...I'll take that.

[nerfer34]

I love how it primes like a maverick.

You're really really progressing over the years at NH. Look at your first homeades and now look at these newer ones.

Really cool.

Sorry that I can't ask a question about the homeade itself.

[Carbon]

Heh, thanks....at the very least, I'm happy that I don't use as much hot glue anymore.

Here's some disassembled pics:



You can see the return spring on the top, and how I dealt with the trigger on this one. It was a bit far forward, so I just used a piece of mending steel. It's screwed down on the back, ziptied on the front. It uses the spring as a pivot, so it takes most of the stress off the clothespin.

I don't glue down the nail anymore..I just hold it down with the trigger plate.


The plate is ziptied around the clothespin, so it's held in place firmly, but can still wiggle a bit.

Edited by Carbon, 05 August 2010 - 10:13 PM.

[Blasphemy]

Whew, it must be the carboniferous period in homemades (I've been wanting to use that one for a little while now. I like it, it's like a slightly oversized Nitefinder with a more comfortable priming mechanism.