Friday, March 22, 2019

Motorized Stirrer

I added a motorized stirrer to my overcomplicated tea maker. I used a motor from an electric knife and a small whisk. I attached the whisk to the shaft of the motor by twisting the wire like a threaded rod. It sometimes unscrews itself. I mounted it on a scrap of vinyl window nailing flange, so that it can be lifted up to insert into a cup and to absorb vibration. It's powered off the 12V center tap of the transformer, and switched independently. I tested it by making simple syrup, mixing 1 cup of natural sugar with 1 cup of hot water, and a teaspoon of vanilla extract. It worked perfectly.


Here's the Amazon Affiliate link for the sugar I used: https://amzn.to/2HzUl1R

TV Tuner Spider (from the archives)


This art project is made with an old TV tuner, coaxial cable, neon indicators, and spray paint. I kept the original power cord, but took out the circuit board. I got it out recently to try to play a joke on my uncle who was visiting. I put the giant spider with glowing eyes and mouth near his suitcase, but he didn't even pretend to be scared.

Sunday, March 17, 2019

Overcomplicated Tea Maker

One time when I was doing homework, I asked my dad to make me a cup of tea. He used the convenient small coffee maker, but left it on too long. That wasted power and could have started a fire. After that, I decided to add some features to try to make a perfect cup of tea and maybe save power.

First, I added an arduino-controlled 3 phase 40 amp contactor to turn the coffeemaker off automatically. There are coffee and tea makers that already have a timer, but the one I have doesn't stop at exactly three and a half minutes. A contactor is like a really big relay, typically used for industrial control and air conditioners. I bought a contactor at the Habitat for Humanity ReStore, and I was looking for a project to show it off. The arduino controls the contactor via a relay.

I added a 20 amp light switch to start it. I attached a metal electrical box to hold teabags. I thought about adding a motorized arm to lift the teabag, but I didn't know how to program that. I might add a stirrer for sweetened drinks. 

Yesterday, I added a platform so that it doesn't take up as much space on the counter. I used a mesquite log, and wood recycled from our old windowsills. I tried to use velcro to keep the coffee maker from falling off the platform, but it stuck to itself better than it stuck to the plastic. Next, I tried duct tape, but it didn't look right. I unscrewed the bottom to clean the inside (because a few years ago some ants invaded it). When I took off the bottom plate I found better solution. I screwed the bottom plate directly to the platform, and then reattached it to the coffee maker.






Amazon Affiliate link for the contactor: https://amzn.to/2OcsZQ2
Amazon Affiliate link for Mom's favorite tea, (lemon ginger): https://amzn.to/2TGzhgF

Friday, March 8, 2019

The Power of Ice

Our weather has been going from hot to cold and back. A couple of days ago, I wanted to do an experiment of leaving a soda can full of water outside overnight because it was going to get down to 24 degrees Fahrenheit (-4 C). Unfortunately, my mom didn't know what it was for, and used it to water her plants. And the next couple of nights, the low temperature was around 65F. So I had to try the experiment again in the freezer instead.
Ice can be very powerful. Glaciers. Frost heave. Burst pipes.
Even though the top of the can had an opening for water to escape, the ice blocked it. It split the can!

Monitor Stand Adapter

My computer has an ultrawide monitor. It's great, but it takes up a lot of desk space. I decided to replace the stand with an older one(I think it's from 2003) that has adjustable height and rotation. Then I can put my speakers underneath and use more of my desk space. I made an adapter plate to attach it by drilling extra holes in the VESA mount because the mounting holes are closer together than the ones on the stand. I tested it in "portrait mode" with Minecraft, and it looks crazy. It is not practical for gaming, but might be good for reading text. After that, I rotated it back to normal, but adjusted the height so it's about 6 inches off the desk. The stand that it came with only does tilt.


Here's an Amazon affiliate link for the monitor I have: https://amzn.to/2TpebmN

Sunday, March 3, 2019

Drill Bit Sharpener

I have wanted to try re-sharpening drill bits for a long time. I think it would be a good way to reuse something instead of throwing it away too soon. I had seen one called the Drill Doctor on Youtube that has its own motor, but it was too expensive. I found a drill bit sharpener at Harbor Freight that was a reasonable price and decide to try it out.

You can buy it online through Amazon, but it costs more. Here's my affiliate link: https://amzn.to/2ExXew8

The sharpener is a grindstone with a jig attached. It works on 2 mm to 12.5mm bits. To use this, you need a drill that spins between 2000 and 3500 RPM. There's a typo on one side of the package that says it could work at 35000 RPM, but I don't think that would be safe. I used my drill press at 2100 RPM and it worked on my first try. It got the bit sharper, but the point and edges aren't perfect. I think I could get better at using it with more practice.

I saw a video on Youtube about a giant automated drill bit sharpener. It was really cool, but it is meant for much larger drill bits in an industrial environment. Here's the link: https://www.youtube.com/watch?v=jx_9GK3sF6g&t=4s