Long Time No See

So I haven't updated this in a while.

But I got good stuff. I built myself a computer from used parts and new parts that I bought in Taiwan! :D

Gigabyte GA-G31M-G2L Mobo
2.0 GHz Pentium Duo
4 GB DDR2 RAM
80 GB + 1 TB HDD's
DVD-RW Burner

Back in US, I stuck it in a cardboard box and hooked everything together to make sure it all worked.

The initial setup of the computer when I came back from Taiwan:

Chyeaa. Ghetto.

For the record, we own a Macbook Pro and an upgrade disk so yea. Closer view of the cardboard box setup I had running. Airflow went straight up.

Even closer view of the box computer.

So then I stuck it in an old case and then I hooked it up to the sound system we have in our house with an RCA cable I cut and soldered to a 1/8-inch jack cable. I also hooked up the TV to it. My dad and I also built a nice "floating" desk to go with the new computer and monitor/TV combination.

Full view of computer with TV with sound system. Little center speakers on the floor under the TV. :D

Desktop view. With card reader jutting out unaesthetically. :P I can get those Wiimotes to work as pointers for the computer too! DarwiinRemote.

Underneath the desk. This desk came from the top of an old cabinet that my dad and I ripped off. We bought the supports and non-OEM screws from Home Depot and spent like several hours trying to get everything right. Ended up we had to prop it up on wooden blocks, which you can see in the top left corner. Still kinda rickety but good enough for non-heavy use.

I also got a used chemical ice pack from a friend, so I decided to have a little fun and try to recrystallize the ammonium nitrate in the water in the ice pack. I first did it by pouring some in a metal cup and putting the cup under a halogen lamp for like an hour. It worked - stuff boiled off and I got nice crystals. But it took way too long and wasted too much energy. So I made alcohol stoves from Altoids tins. :D

The base for the alcohol stove also acts as a carry case! :D

Grille for holding whatever you're heating, and the altoids stove on the right.

Little holes drilled in the side of the base so that air can go in and burn the alcohol. It'll make sense by the next next picture.

So we open the altoids tin with two rolls of gauze inside for absorbing and wicking off alcohol to burn...

So this is the stove fully set up, with that metal cup on top. The holes in the base draw in air which mixes with the alcohol in the gauze-roll wicks. That is lit through the hole on the lid and the flames reach up and heat the cup. :D Simple and effective. The grille was made from a computer fan grille with 4 bolts and nuts. Pretty simple.

Crystallized ammonium nitrate. Too wet to be used for anything, mostly proof of concept. You can see a few drops of liquid on the sides there near the top.

And that was what I did over the summer.

Nerf Gun Converted into Airsoft Gun

Hey, since my last post I got the Nerf Recon CS-6 for a few months now. Upon rediscovering the fun of shooting airsoft guns, I wanted a more powerful one than the cheapo pistol I had from Taiwan, so I "modified" my nerf gun a bit.

Actually, my nerf gun wasn't modified. This conversion was more of an attachment than a modification. (I did, though, modify the nerf gun to shoot farther. Standard air restrictor removal and penny spring mod. Shoots 50 feet with streamline darts).

Here's how it works.

I took a nerf dart and cut off the head. Now it's a nerf tube.

I took a steel airsoft barrel from an airsoft tank that I took apart quite some time ago and
1. Attached a circuit hook-up wire across one end with masking tape
and
2. Put a small line of masking tape on the inside on the same end of the barrel, making a full circle. (you can see it a bit inside the barrel here)

I stuffed the steel barrel into the nerf tube and the modification is now complete.

The small wire on the barrel end serves to keep the BB in the barrel when aiming and loading (muzzle-loaded), so it doesn't fall out the end into the nerf gun itself.
The small lining of tape serves to hold the BB in the barrel when loaded, so it doesn't slide out when the gun points down.

By simply stuffing the above modified dart into the barrel of the nerf gun, the nerf gun was thus converted into an airsoft gun.

Using a simple setup with a stool, measuring tape, a laser pointer, and a shopping bag, I used kinematics to find that the crude approximate speed of the gun is around 277.788714 fps (feet per second). This is using 0.12g low-end BB's. If a 0.20g standard BB was used, the speed would have theoretically been (using conservation of energy) around 215.174213 fps. Which is pretty close to some mid-to-high-end spring-powered airsoft guns. Dang.

What I did was put the gun on the stool and made sure it was level by eye. I used the laser pointer to line up the gun with a paper shopping bag 10 ft away. By firing the gun and finding the height difference from launch to bag puncture, I could find

1. the time it took to get there.
2. using the time found, calculate the speed it had over 10 ft.

Which came out to the wonderful number you see above.


When I have more time, I'm going to make a better setup for better speed calculation - using bubble levels and a stiffer bag for better measurement.

Hey, BSoD!

I returned to my PC partition and started playing around with various games. One download came up as a virus on the scanner so I deleted it. Unfortunately, something went wrong. Several more virus alerts came up as well as strange IE8 ads so I closed down the ads and deleted the viruses. So I thought, "Hm, I better turn off the new BCM94321MC Apple Airport Card I installed in my laptop for Wireless-N in the Mac Partition," and did so. About 3/4 of a second after I hit the wireless switch, the laptop freaked out and went BSoD on me. Rebooting had no effect.

Several options:
1. AntiVirus Boot CD scan -- in progress.
2. Uninstall custom BIOS needed for new wireless card and replace with authentic - maybe.

It may be that the new wireless card's driver is interfering with something -- dunno what. The two different BSoD errors I got on two separate reboots seem to be pointing to a driver problem. Oh well. I gotta remove the viruses first. So far, scanning for 2 hours came up with 7 alerts (some of which are kinda dubious).

Interesting.

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.

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.

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.

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.

New Design V2

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

Power.