Random projects that I do to improve my life, try out an interesting new technology, learn a new skill, etc.
Part of my bicycle-lighting project involved crimping a splitter cable to split the output of the dynamo to the front and rear lamps. I used a DuPont connector for that because I had recently bought, after 4 years of consideration, a proper DuPont crimper. The input and output wires were 24 AWG solid wires with…
Recently finding the need to bike home in the dark, and not wanting to regularly charge a battery-powered light, I decided to buy a used bicycle dynamo (for $40) to power a front and rear bike light. The dynamo is a bottom-bracket dynamo, which means it’s meant to be mounted on the bottom bracket (where…
I recently bought a used cross-slide vise on craigslist for $35. It is a machinist’s vise mounted on two ways at right angles, with leadscrews controlling the vise’s movement along each way. It’s meant to be used on a drill press so holes can be located in the same manner as in a vertical milling…
Soldering iron tips are made of copper plated with a very thin layer of iron. Unfortunately, this plating can oxidize if you don’t clean and “tin” it (that is, coat it with solder to protect it), and this can be very annoying because the oxidation is difficult to get off and prevents the solder from…
A spinning gyroscope can balance on a pivot, defying gravity by remaining horizontal while resting just on the tip of its axle. Instead of falling off the pivot, the gyroscope circles around it. The explanation for this amazing feat lies in the effects of precession. Like all other objects, the rotating wheel of the gyroscope…
I made a gyroscope. Part of that involved casting 12 zinc weights to go around the rim of its rotor, which gave me a lot of practice ramming and pouring molds, and I learned a lot. Firstly, for my extremely rudimentary dirt-bonded sand, the right moisture level is just enough to turn the sand noticeably…
WARNING: This is quite a dangerous project if you don’t know what you’re doing. Take proper precautions if you decide to try this: never leave the stove unattended, plug it into a GFCI outlet, use proper wire connections, and use a cord of the proper gauge. Above all, USE COMMON SENSE; IF A SITUATION LOOKS…
Introduction There is a medicinal ointment popular in Hong Kong called 白花油 (“White Flower Oil”) that produces a cool, minty feeling when rubbed on the skin and is used as a pain and itch reliever. (A similar product called 风油精 (“Wind Oil Essence”) is used in Mainland China.) Interestingly, one of its main ingredients, which…
Introduction and Rules 24 is a card game in which players try to use the basic arithmetic operations and each of four numbers exactly once to get the number 24. I play the game with my friends as follows: in each round, 4 cards are dealt face-up, and the first person to yell out a…
Introduction I have some dirt,I have some sand.Uh! Green sand. I poured zinc,into the green sand,Uh! Sand casting. (The PPAP song went viral when I was in elementary school and the funny lyrics made an impression on me. So here we are.) My previous attempt at casting focused on casting a detailed model with no…