Vinyl- Filled Wood Carving

Step 1- I asked Mom to draw a design. I used small sections of thin wood I got free from Home Depot and Lowes. I wanted a design that could be made with a series of small holes using only one size of drill bit.

Step 2- I used my drill press to drill the holes

Step 3- Fill the holes. I used a tube of vinyl filler that was meant for repairing counter tops. It happened to be bright orange.

Step 4- Let it dry and then sand. I had to wait a few hours before it was dry enough. Then I sanded off the excess filler to reveal the design.

Power Supply- Major Upgrade

Yesterday, I went to a sale at the Georgetown Texas Habitat for Humanity ReStore. They mostly sell used building supplies, but they also have electrical stuff such as light switches. The sale was $5 for a 5-gallon bucket of stuff. I packed in drill bits, a screwdriver, wheels, paint, chain, switchplate covers, an electrical box, a light fixture, a green lightbulb, and much more. 
One of the items I got was a 150 Watt landscape lighting transformer. This transformer had a NEMA20 plug, but it wasn't original or necessary. The cord had been painted. We don't have anything compatible with this type of plug, and I bought it to hardwire onto my power supply. My house has NEMA 15 plugs, which only work with NEMA 15 devices. NEMA 20 T-Slot outlets can work with either. They are more common in commercial buildings.

I think it is from 1998 because that's what the sticker on the back says. The modern equivalent of this transformer would be smaller, lighter, and less reliable because now they make switch mode transformers instead.

Just like the previous transformer, I removed the sensor/timer circuit because I want it to turn on instantly. I didn't have to do any soldering to install this transformer. Adding it made my power supply even heavier. The transformer takes up only 1/3 of the box. The box is so large that I had to mount it underneath the power supply box. It had a door to access the mode select switch. Since I took that part out, now I have extra storage space. I could store extra fuses in it.

Speaker Control Box

My "Lair" is the area under my bed platform. It's like a bunk bed but I never sleep under there because it's too short. I like to listen to music and watch Youtube videos there because cozy and dark. I have subwoofers mounted to the ceiling so the alarm clock will shake the bed above.

The box between the subwoofers allows me to disconnect either them or the tweeters. There's a piece of double sided perf board with two 68 ohm resistors, one for each input channel. This board eliminates the hum from the speakers when there's no audio being played.

 The switch is a double pole 20 amp mains light switch. It is like two standard light switches combined. 

For the wire between the amplifier and the box and the box and the tweeters, I'm using 18-4 sprinkler wire (meaning it has 4 18 gauge conductors) The subwoofers are wired directly into the box.

The switches I am using have a Loop Hole. It is designed for making loops on the end of wire, but it sounds funny. 

How to Trick a Smart Battery Charger

The problem with multi chemistry smart battery chargers is that they will occasionally think that a nickel chemistry battery is unsafe to charge, assuming it is a lithium battery that is too low to charge safely. This is good if you actually have a lithium battery that is over discharged, but frustrating if you want to charge a nickel chemistry battery that is safe to charge.
To get the smart charger to charge the nickel battery anyway, I have to connect the battery to the 3.3 volt rail on my bench power supply for about 30 seconds. I used the 3.3 volt rail because it has a 1 amp current limit. I could charge the battery the whole amount with the 3.3 volts from my bench power supply, but it would be inefficient, could over charge the battery, and would overheat the regulator. I used the bench supply to charge the battery just enough so that the smart charger can recognize it. Warning- Do NOT do this with lithium batteries, which are more prone to catastrophic failure.
We had a similar problem with a smart lead-acid battery charger. Grandma's power wheelchair was parked in our house for over a year. The two lead acid batteries had self-discharged too low. The smart battery charger refused to charge them. New batteries would have cost at least $100. To trick the smart charger into working, we used a simple old car battery charger to raise the batteries' charge just enough for it to recognize. After that, they charge with the smart charger every time, with no issues. 

Project from the archives: Nap Mat with Book Pocket

Mom writes:
When Griffin was in kindergarten, they still had nap time for the first half of the year. For a kid with ADHD, this was problematic to say the least. His brain was too busy thinking to fall asleep. He would talk or make noise by crashing into the legs of the desks. We tried to help by sending books to keep him quiet. Pop-up books were especially good for this.
I added a pocket to his nap mat (they used towels that year) so that he would always have a book with him and it wouldn't get lost. We made the pocket out of an old t-shirt, probably one that was a hand-me-down from his Uncle Michael. I think Griffin helped with the sewing. He has always liked machines, and the sewing machine was no exception. This idea could also be used to add zippered pockets or a pillow to the end of a towel, for example at the beach.

Battery Storage Box

 After going through my battery hoard, which included some that expired in 2004, I still had about 10 pounds of usable AA batteries. They were all mixed together with different brands and ages, so they can't be used in devices that use multiple batteries. It's best to use new batteries from the same batch together so they don't reverse charge the weaker batteries. Even though these can't be paired up, they are still good to use in devices that use single AAs such as my Rift controllers, clocks, and some wireless mice.  All of my AA batteries are somewhat used and some are rather old and expired, so they can last in the Rift controllers from a couple minutes to a few weeks.
I took 3 lbs of dead batteries to be recycled. We took them to an Austin public library since IKEA won't take batteries anymore. Batteries Plus Bulbs will only take 1 lb for free, and the dump requires batteries for recycling to be individually wrapped with tape. Recycling them keeps them out of the landfill and the chemicals can be used to make new batteries. However the recycled batteries I have seen for sale cost more than the regular ones and they were already leaking in the package.

For my 10 pounds of usable AA batteries, I needed a storage box. I had the idea of making a dispenser. At first I considered 3D printing a dispenser base and making the top part out of cardboard. All the 3D models I found used a track for the entire length which wouldn't work well because I have too many batteries and they are too heavy. It would have taken a lot of plastic to print, with lots of supports, and it might jam with too many batteries. So I asked my mom to design a box made completely out of cardboard. I found a corrugated cardboard box from my new box fan, and a thin cardboard box from Triscuits. The Triscuit box was almost already the right size, but wouldn't have been sturdy or tall enough on its own. Mom added corrugated cardboard inside to make it sturdier and a closer fit. Then she made another section of box with the corrugated cardboard, with a ramp at the bottom. We used packing tape to connect it. Then I drew a circle to show where to cut a hole at the bottom to dispense a battery. It turned out that I needed a slightly larger hole as well as a hole on the opposite side. Then the battery can be dispensed by pushing it out with your finger from one side.

Next, I zip tied a piece of MDF to the wire shelf next to my computer desk. Then I taped the box to it. Now I can dispense batteries for the Rift controllers while wearing the headset, without even looking.

 Boring math time: 10 Lbs is about 4.5 Kg. If 10 batteries weigh 240 grams, then each battery weighs 24 grams. So I have about 187 batteries.

Rustic Clothes Rack

I used to organize my clothes for the week by placing piles on the stair railing. But Mom complained that it looked messy, and suggested I use hooks instead. Apparently I had first thought of this idea seven years ago. After I was done with this project, Mom found an entry in my Idea Journal from 2011. It was an idea for "Hooks for outfits for each day of the week. Attaches to bunkbed". This clothes rack attaches to the wall, not a bunkbed, but the idea is the same. 
I built a rack with 4 dowels. It works great with clothes on hangers, but it could be used without hangers. It looks rustic because I used a weathered fence board for the back and ligustrum branches for the pegs. This was a good recycling project because Dad wanted to throw away the old fence boards. The ligustrum dowels were cut from my backyard and are "sustainably sourced" because the tree will grow back quickly even though we never water it and it is growing wild.
I put the clothes rack outside my bedroom door, because there was unused wall space in the hallway between my room and the bathroom. To install the clothes rack, I used a studfinder to mark where to put the nails. I pre-drilled with my cordless drill, and then I hammered in the nails.

Oculus Rift Wrist Strap Upgrade

The Oculus Rift touch controllers come with wrist straps so that you don't accidentally toss the controllers. This is especially important when doing sports such as paddleball in RecRoom. I was playing this game a lot, and I found the included wrist straps to be uncomfortable. They were too thin and non-stretchy.

Photo from CNET

I decided to replace them with t-shirt yarn. This is yarn cut from an old neon yellow tshirt. It is a good way of recycling that we learned about at a Maker Faire. It wasn't too difficult to replace because the original straps were mounted to rubber plugs that were inserted into slots under the battery cover. The knot in the tshirt yarn was hard to fit in the slot, but I got it to work. It needed a size adjuster. First I tried a rubber grommet, but it was too loose. Then I used a piece of plastic with a hole drilled in it. It slides to tighten or loosen. This is significantly more comfortable than the original because it is made of soft cotton fabric.

Amazon Affiliate Link for the Oculus Rift: https://amzn.to/2MObu7z

3D Printed Case with Heatsink for Raspberry Pi

My Raspberry Pi B3+ with 3D printed case

Image from Amazon https://images-na.ssl-images-amazon.com/images/I/71dty6aQaML._SL1080_.jpg

I recently purchased a Raspberry Pi 3B+. I measured how hot it would get under full load and it was around 75C. First, I 3D printed a case from Thingiverse.com to protect it. Then I decided to add a heatsink to it. I cut out a section of the case, applied thermal compound to the processor, and super glued a salvaged heatsink to the case. The heatsink already needs cleaning because I forgot to clean it first. With the heatsink, it mostly stays below 70C.

The set up was more difficult than a regular computer because the operating system wasn't pre-installed. I connected the Raspberry Pi to an old monitor, a cheap keyboard and mouse. I connected it to the internet via ethernet first, and then set up the built in wifi after adding the case. I loaded the operating system from my computer to a microSD card. I had trouble finding a microSD card because most of my devices use full size SD cards. It took two tries and 45 minutes to install the the OS, even though the instructions said it would only take a few minutes. That was frustrating.

The Raspbian Linux operating system took a little bit of getting used to. It's very similar to Windows 10, but most things are in a different place. For example, the tool bar is stuck at the top. Also there are different keyboard shortcuts that I haven't learned yet.

Amazon Affiliate links to the products I used in this project:

Thermal compound :https://amzn.to/2JCnB8J

Raspberry Pi 3 B+ https://amzn.to/2M89UwO (I found it cheaper on Arrow)