Category: Random Projects
Random projects that I do to improve my life, try out an interesting new technology, learn a new skill, etc.
-
A problem that I’ve had is that I keep forgetting to close the garage door at night, which lets in the elements (and also rats). After being pestered for some time by my parents to find a solution, I finally came up with this. The solution is to turn on the overhead lights any time the garage door is open at night. Since the garage is in plain view of my house, this makes it really obvious when the door is open. Unlike something that automatically closes the door, a solution like this doesn’t need control of the garage door…
-
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 an insulation diameter of about 1.3 mm. A DuPont crimp actually consists of 2 crimps, one onto the stripped wire, and another onto the insulation for strain relief. The biggest challenge when attempting to crimp 2 wires is getting the insulation of both properly into…
-
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 the pedals are mounted) and is driven by the tire tread. This contrasts with bottle dynamos which are driven by the sidewall of the tire, potentially wearing out the sidewall. There was no space to mount the dynamo on my bottom bracket, but thankfully it…
-
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 machine. The vise is also useful since it allows the piece to be moved under the spindle without loosening and re-clamping it as in a normal machine vise. The vise was originally bought at Harbor Freight, a store known for affordable but low-quality tools. …
-
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 wetting the tip. There are a number of ways to get stubborn oxidation off. The recommended way is use some sort of tinning compound designed especially for this purpose, like sal ammoniac. Over the years, I’ve tried a few alternative methods, mostly without success. First…
-
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 is subjected to gravity. However, as long as the gyroscope spins, precession overcomes gravity by transforming it into a force that causes the gyroscope to circle instead of falling. The Way Things Work by David Macaulay and Neil Ardley At the suggestion of my physics…
-
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 dark, indicating that the clay is fully wetted with water, but not so much that it sticks to the rammer. While many hobbyists on the internet recommended using a peen-shaped rammer to better compact the sand, I found it easier to simply ram the …
-
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 DANGEROUS, IT IS. Having come upon an Instant Pot® Duo Crisp™ Air Fryer lid, I decided to take it apart and convert it to an electric stove. Disassembly Disassembly was pretty easy, with the exception of the first two non-obvious steps: Take off the intake…
-
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 makes up 40% of it, is methyl salicylate, a chemical often used to soften rubber. The specific use case I had in mind was restoring some grip to the time-stiffened rubber feet of an old typewriter. They had deteriorated to the point where the …
-
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 solution for how to get 24 wins those cards. J is 11, Q is 12, K is 13, and A is 1. Since it is occasionally impossible to find a solution, the first player to declare the round “impossible” receives the cards after the rest…
