7 replies to this topic

[Darksircam]

Simple pull-and-shoot blaster. It's like those toy bows... but it looks stupider, and works better.

A lot of these items can be substituted for other stuff, but this is how I did it.

Wire Cutters
Hot Glue + Hot Glue Gun
Tape
GOOP
Drill with drill bits, 1/16" for paperclip or same diameter as your nail (see below)
Sandpaper or file

Hand pump from TAP Plastics or similar. Gotta have a strong spring.
Handle Extension. Something that fits inside the hollow part of the hand pump. For me, this was a trash ballpoint pen.
Paper Clip (or thin nail)

Barrel:
PETG
OR
PVC Coupler + 1" stub of PVC and barrel of choice


So I found some hand pumps at TAP Plastics for sale: $1 each.
http://www.tapplasti...ct.php?pid=174


It had a spring, really good airseal, and a handle. Pretty much all it needed to become a foam-flinging device was moving the spring location. And that was the problem - the handle was fused to the plunger rod.

Sticking the entire thing in boiling water would remove the parts, most likely, but there's still the problem of achieving maximum efficiency. The handle doesn't go all the way in when stock.


There's a weird tab in the cap that prevents it from going further in, even without the spring.

So I made a new handle.


Snip off the tip of the plunger tube, we don't need it. The ball bearing will fall out. Also remove the large pump part of the plunger.


Seal the plunger with hot glue. It was designed to let air through, we don't want that.

Prepare your handle extension ballpoint pen. Wrap it in tape until it fits into the handle snugly. Push it about 1/2" in.


Drill through your plunger/pen/tape with the 1/16" bit.
Then pull the pen out, apply GOOP, and stick it back in. Lock it in place with the help of GOOP + paperclip.


Remove any metal or plastic that's sticking out with a file or sandpaper. The cap has very little gap, and if anything's poking out it'll get stuck.


Stick the spring back on, lube it up with anything (No washer, so petroleum jelly is a go).

If it's PETG, your journey ends here. TAP Plastics pumps are just the right size for PETG to fit around.



Otherwise, take a PVC coupler, hammer some PVC in that, and hot glue/goop it in.

I'm considering adding a cross-piece to the handle so it's easier to prime. Maybe a duct tape-wrapped nail.

Added that PVC coupler. Just stuck a lot of hot glue on it... works with any feed-assist hopper, which is what I'd expect from something with power like a modded NF. Gets more consistent ranges too. I was getting misfires with the PETG.

Still a work in progress, fixed the materials list. Working on making a trigger system...
If you can't order springs off McMaster, these are good viable springs. Not good for a primary, but for integrations and small sidearms, yes.

Edited by Darksircam, 08 June 2011 - 12:12 AM.

[NerfRogue83]

This reminds me of why I love Nerfing---fun doesnt get much cheaper or readily available.

[shmmee]

That's hilarious. Makes me want to bust out my old blast hammer, and replace the peg with a coupler (just for lutz).

Would this count as a homemade? With costs totaling less than $2, and with the addition of a trigger, I think it could be a competitive contribution to McNumbers contest.

[Darksircam]

Making a trigger would increase the cost. Power would also be hampered, as it loses some draw distance.

I am testing this out with a CPVC catchface - the final version will use epoxy.

A PVC catchface would be optimal, but the ID of the plunger tube is slightly smaller than the OD of 1/2" PVC, making this impossible. I'll find a washer for the catchface sometime this weekend.

Prices may vary: My local TAP Plastics had these on sale, but the website's prices are also unreliable. At least you're getting a spring and plunger tube for cheap.

One problem I see is a possible loss of airseal efficiency. As the front of the plunger head slams into the beveled end of the tube, it gets compressed into that area and gets bent.
The rear seal is still fine, but the front seal is dead.

Seeing a total cost of about $3 or less, similar to the "Smallest Homemade" from http://www.nerfrevol...c.php?f=9&t=680


Edit: Ok. It's long, and stupider-looking than before, but I have created a very inexpensive blaster. With a simple clothespin, 2 nails, cable ties, and a scrap of CPVC, I have completed the task of adding a trigger.

A handle would be nice... but not really optimal, as the only place to attach it would be the screw-on cap.

Still similar ranges, strangely. Probably because I was releasing it incorrectly last time. Lesson learned: Triggers release faster, especially when your handle is nonexistent.

Current pics


That scrap of wood limits the trigger travel so the nail doesn't pop out. I pulled it from another clothespin.

The barrel I use for this is a 3" PETG barrel with 1" of nested 17/32" brass, nested in 4" of PVC. Basically a universal pistol barrel.

Edited by Darksircam, 07 June 2011 - 08:59 PM.

[Flaming Hilt]

I feel like this would make a nice attachment to any gun. That is to say, like people used to do with SSPBs on NFs. You could slap this on the bottom of a SNAP and have a nice little lefty-fired backup that nobody saw coming when they rushed you, thinking you were out of ammo.

[Carbon]

I like this, a lot. It reminds me of my old syringe popgun, but better because it comes with its own spring, and a much better plunger rod. Gonna have to try this out...

[Darksircam]

I tried to find a washer to reinforce the catchface, but my search turned up nothing at Home Depot except a cut washer.
Not sure if you can find these at normal hardware stores - couldn't find any at that Home Depot, but that may be due to my lack of knowledge and being rushed. It should be near the fiberglass resin.

The catchface doesn't have any major signs of wear yet after a minor duel with friends, so that's good. One major problem is that the blaster's pretty long. CuppaSteve on NRev suggested this could be a ballistic knife... I say it's more like a gunblade gundagger.

So I slapped on my old melee barrel attachment (really just for barrel tapping, tip isn't covered so stabbing is dangerous)



Terrible ranges because low-volume springers don't like PETG barrels. If I make a CPVC+PVC version and make the tip safer, this would be completely viable.

As an integration or attachment: 3/4" thinwall PVC snaps onto the body snugly. However, it's at least 20 cm (8 inches) long without barrel... unprimed.

[shardbearer]

I think that would work a lot better as a mechanical pusher. I would put a dowel inside the knife and sticking out the back, and put it down the PT with no barrel.

But this thing is pretty cool, nice use of existing materials. I have only seen these inside fiberglass resin containers, didnt know they sold them seperately.