Sunday, November 22, 2009

Given Up

I gave up the homemade nerf gun project. Too much money wasted, and with the looks of the new breech, it would have cost just as much to buy a normal Nerf gun. So I bought a Recon CS-6 and modded it according to here and here. Except instead of pipe cutters, I used a Leatherman knife with the handle bent in a way to hold the bolt in place while I rotated it. Now instead of the 25' range I got, I got around 40' of range! But the gun is too powerful, apparently, as the Nerf darts now fishtail and curve off around 30'-35'. I am working on that.

Tuesday, November 17, 2009

Nerf Gun: Construction Five

Considering installing a new breech, because current modified Unknown breech has the following shortcomings:

1. When the dart is inserted, it must be pushed inwards a little bit to create a seal with the barrel.
2. 1/2" PVC doesn't hug the dart too closely.
3. The seals on the breech are a tiny bit too tight. That makes for hard reloading.
4. The hole through which the darts are loaded is just terrible. :P No possibility for interfacing with a gravity-fed magazine as formerly planned.

Reason #1 had the most impact, as a breech was supposed to make loading easier. It's hard to do something that exact while running and dodging darts and tracking targets at the same time.

So back to the drawing board. Partially. Air tank and hose nozzle seem to be very effective, though. On retrospection, picking a small air tank to be refilled after every shot was a good choice, as the hose nozzle had only two settings: all sealed or all released. No way the airflow could be controlled consciously.

So new design: If 1/2" CPVC fits smoothly inside 3/4" PVC, then I will cut a semicircular cross-section off of the 3/4" PVC for a breech, and "cone out" the inside of the 1/2" CPVC. Because the hose nozzle requires a 1" PVC pipe to attach to, I'll need a 1" --> 3/4" PVC adapter as well. Back to Ace Hardware, hopefully for the last time.

Monday, November 16, 2009

Nerf Gun: Construction Four

Almost done.

Air leaks were sealed by using some of the inner tube where I got the tire valve from. Surprisingly, two layers of the stuff gave a perfect seal. Here's a closeup of the seal. It was sealed across the bolt slot and in rings on the ends of the loading slot on the smaller pipe.

Closeup of end of air tank with new tire valve installed. Tire valve was cut out from an inner tube.

Full view of the gun. In all its glory. :D

One thing left to do: mount the bicycle pump below the Unknown breech and connect to tire valve. That screw connection that connects the air tank to the hose nozzle needs to be glued up, too -- that's as leaky as the sound-proof practice rooms in the NBTHS music department.

Ciao for now.

Sunday, November 15, 2009

Nerf Gun: Construction 3

ARRRGG air leaks.

Nerf Gun: Construction Two

Update 2:
Cut some holes in some of the pipes.

You can see the hole cut in the 1" PVC Pipe connected to the hose nozzle -- that's for that bolt over there to pull the barrel (the smaller PVC pipe) forward and back to reveal a hole for loading Nerf darts. That ring on the smaller pipe is for sealing the barrel mechanism as well as possible.

That hole there is for loading Nerf darts.

View of the barrel itself. I actually came across a problem, where the air would leak around the pipe. So I'm going to line the hole with electrical tape until it seals.

The little hole for the bolt on the bottom. I'm going to expand the hole, once I get the drill back from the neighbors.

Nerf Gun: Construction

Here we go, went to Ace Hardware, spent freaking $37 on connectors and pumps and the like. Not even for the pipe (which I already had and i think was less expensive than the connectors). Anyway, PICTURES!

What I've got so far: the handle with O-ring and half the air tank on the bottom there. My plan for the air tank is to cut the valve from a bike tire and place it in a pipe endcap and cement that on.

This bunch of connectors attached by PVC cement.

O-ring connected to tip of hose nozzle for better seal with barrel. How did I get it so centered? Well since you asked...

I used a bit of 1" PVC pipe to center it by screwing the pipe onto the hose nozzle's tip.

I then put superglue onto the metal ring on the hose nozzle and slipped the O-ring in and doused it in more glue.

The barrel's design is the "Unknown Breech", which will screw directly on to the hose nozzle. A few changes, though. Instead of 2mm foam sheets to fit the barrel with the breech, I'm using several rings cut from 1/2" PVC pipe endcaps filed down to fit. And an O-ring between two of them. The tip of the barrel to be contacting the O-ring that was glued above will be filed down as to facilitate a better dart loading mechanism. I'm also working on a magazine to go on top of the Unknown Breech.

More updates to come as progress continues.

Thursday, October 29, 2009

New Design V2

Air tank. Pump. Garden hose nozzle. Unknown's breech. Maybe a gauge.


Friday, October 23, 2009

Nerf Gun: Design Change

Creating a new design that will be pneumatic powered. With an actual trigger system. It should be a lot easier to design, implement, and build.

Monday, September 28, 2009

Leaks in the Air Pump

Title is self-explanatory. There seem to be leaks in the air pump. School is restarting and robotics season is kicking up so this will probably be worked on over a long while. T_T

Sunday, September 27, 2009

O-Ring Fault

There's a design flaw with the pump. Spring and everything installed, everything works. I need to see what's the problem with that O-Ring inside the pump and install a trigger system. The problem is that it compresses air, but leaks if the motion of the plunger stops -- problem.

New Spring Design for Nerf Gun

After some mishaps with two springs that did not work as planned, I changed the spring design to accommodate a pulling spring nested in the middle of the firing plunger. I also doused all connections in cyanoacrylate and hot glue. :D

Saturday, September 26, 2009

Homemade Nerf Gun: Part II

Some more pics of what's been going on.

T-Joint and couple-inch section of 1/2" pipe. Will be used to cock the gun. Also pictured is a ring made from a PVC end cap that will be used as a stopper.

I had taken out the cracked pump to repair. To accommodate new designs, I shifted that pipe mount (that used to be a couple notches back) up. You can also see how I stuffed that 1/2" pipe into the pump -- by melting it. >=D

New firing anchor for new design. Gorilla glued to two PVC pipe mounts.

The firing anchor is temporarily mounted this way to provide the Gorilla glue with the "clamping" that it needs to set properly.

Formerly cracked pump. The crack was pumped full with Krazy glue (ethyl cyanoacrylate) and then electrical-taped for sturdiness. Once the Gorilla glue sets on the firing anchor I can put it back in.

Right now this looks mumble-jumbled but I do have a set plan. I'll upload it later. Handwriting is horrible on it, though.

Wednesday, September 23, 2009

Homemade Nerf Gun: Prototype 1

New project: Homemade Nerf Gun.

This idea started with a toy pump used for pumping up an air-powered airplane. I attached a length of 1/2" PVC pipe to the end to accommodate Nerf darts, and rigged up a system to power the entire mechanism via bungee cord. It was a basic bow and arrow, and was operated in the same way.

General view of the gun. The black pump, white PVC barrel, steel reinforcement are clearly visible. As is the bungee cord, which hooks onto the bent metal thing on the end of the barrel.

Back view of gun -- reinforcement visible.

A bolt on the handle serves to stop the plunger from impacting the PVC barrel inside the pump, as doing so propels the barrel out from the frame like a bullet.

The connection between pump and barrel. Both were whittled and filed down to fit each other, as it is a dry fit.

Front view of gun -- barrel, reinforcement, and bungee anchor are visible.

The result of firing the gun with the bolt on the handle in place. It placed all the stress on the outer casing of the pump, and it cracked a few inches.

I'm currently working on a new design that will be considerably more complex and will be spring-powered.

Sunday, July 26, 2009


Haven't shown my face in a while. Again.

What has happened since my last update? My dad and I have installed an auxiliary input to my dad's 2005 Corolla, with a 6-CD Changer. We followed some instructions online which put us in the right direction, but had to do a little tinkering and testing to get it right. Now his iPhone is acting up and refusing to output to the headphone jack when it is plugged into the car. Not sure why that is yet.

And I have revamped my Crayola marker butane gun. Made it into a two-Crayola marker butane gun. Except that the firing isn't all that reliable nor is it any more powerful. I need to find an increased diameter, not an increased length (which is what I did) in order to make it more powerful. Project on hold.

With the boredom of summer, I'm going to research and build a proper HHO generator. Hopefully.

Wednesday, April 29, 2009

Recent Fun on the Computer

For the past few weeks I've split my hard drive into its fourth and final partition, formatted in HFS+ (those who know what that is probably know what I'm doing ;]) (Partition 1 = Windows XP SP3, Partition 2 = swap, Partition 3 = ext3 for Ubuntu 8.10, for those who are curious). I've been wrestling with this operating system, getting Time Machine working was no biggie but I still don't have Wi-Fi (3945ABG wireless card not supported...drivers are being developed as we speak though), line-in/internal microphone, or the built-in Thinkpad Active Protection System working. Sleep doesn't work either. I tried to get that to work and the result was first a kext error and then a kernel panic. Joyous. I then reinstalled using iATKOS 5i and got rid of all the crapware that I had installed. It seems stable now, but I still wish sleep worked.

In the physical world, I took apart 3 hard drives and harvested monstrous neodymium magnets and 3 spindle motors. And lotsa shiny aluminum disks.

I also tried cauterizing nerve endings on a painful sore/cut wound. I used a piezoelectric igniter (lighter-grade), grounded another finger, and zapped the wound. The pain was white-hot but it became numb afterwards.

Not much more happening b/c of FRC season. Just random shooting moths with plastic BB guns. Planning on revamping that butane gun made from a crayola marker, making the combustion chamber a bit bigger to make it a bit more menacing. Hee hee.

Wednesday, March 11, 2009

Projectile Launcher

I regularly look on the Instructables website (esp. the tech section) for various hacks and projects that I can pursue. One such Instructable was the butane-powered "gun" (more like miniature cannon -- it's not very strong) made from a Crayola marker and a Bic pen. And a lighter. So several weeks ago, I built it. It works. Barely. It works exceedingly well with the right projectile (rubber o-ring thingy with a screw through the middle). Pencil erasers are especially good projectiles -- they fit perfectly in the Bic pen barrel. However, it is not efficient nor is it strong enough to be of any practical use other than proof-of-concept. I'll post pictures and link to the Instructable later.

Thursday, February 12, 2009

Jam Jar Jet Update


I've found some 3/8 drill bits and HAND-drilled (meaning turning the stupid bit around by hand and with nothing else) a single hole in a tomato sauce glass jar cap. And widened it using a can opener. Funfunfun. I've got the thing to ignite using the same rubbing alcohol and have it run for a couple seconds before it chokes itself out.

Possible reasons for choking out:
-gets too hot too fast; liquid alcohol evaporates quicker, messes up fuel/air ratio. there actually seems to be a certain temperature range that makes the thing go better.
-hole is of a bad size. i don't think so, because i've been slowly carving my way up from 3/8 to near 5/8 holes.
-no diffuser. probably not the main reason, but may contribute to the problem. alcohol gets pretty agitated by the constant barrage of explosions inside the jar.

It's fun to ignite. At first, when igniting a cold jar, the flame propogates from the top of the hole where it was ignited, running down the inside wall of the jar in a ring of fire until it gets to the bottom. Then, it coughs and starts to run like it's supposed to. It actually sounds like a car engine, starting slow then slowly speeding up. Then it chokes itself out. If the jar is warm/hot when it is first ignited, there is a HUGE jet of hot gas that BURSTS forth before it starts up. The problem is, if it is too violent of a starting jet, it doesn't start and just sits there. Dunno why.
The exhaust (especially leftover in the jar from running it) smells funky. The cut edge of the cap and several metal shavings in the bottom of the jar have both turned red from corrosion.

Wanna Arduino

I wanna Arduino.

Monday, January 26, 2009

New Project!

I have decided that the HHO Torch is going nowhere and that its efficiency at what it does will not be sufficient for my needs until I can get more information and materials. Thus, the project is suspended.

Taking its place is the creation and experimentation of valveless pulse jets, starting with the Jam Jar Jet featured in Make Magazine. Since I don't have a 1/2 inch drill bit, I'm drilling one 1/8 hole and several little holes around it in a circular/star arrangement. I'm hoping that works. I've done it first on (you've guessed it) apple juice bottles, but they were too tall and narrow to be effective. Thus, I've cleaned out 3 tomato sauce jars and one bamboo shoot jar to use. They're glass. I've done the same thing with the holes as mentioned above, and am testing the bamboo shoot jar first. I'm using rubbing alcohol (70%) as fuel.

BTW, I've found some 30% hydrogen peroxide. But it's old. I have yet to see whether it has lasted all this time.

And stemming off the last post, I have not (to date) spent $$ on any of my projects (except for a transistor from RadioShack, and my current soldering set). All the materials and tools were either gifts or garbage. Usually it's the latter.

I have updated my Thinkpad T60 with a new 320 GB WD Scorpio Blue 2.5" hard drive. Now I dual-boot Ubuntu and Windows, as opposed to single-booting Ubuntu. However, it makes this strange clicking sound every 10-15 seconds when it's idle...might be the safety feature on it. I'm thinking to add an internal bluetooth module, but I remember that my particular model (1951-44U) was not capable of an "official" bluetooth upgrade. Oh well.

I have hacked a Taiwanese rubber band gun to become more powerful. Now, it will shoot with the same power of a regular person if the proper rubber band is selected. I've lashed together an extension made of a toy tank turret fragment, and 5 pieces of bamboo chopsticks. And lots of cyanoacrylate.

More info will pop up randomly like above later.