The Fine Art of Acid Etching Brass

If you were building a recreation of the James Watt micrometer, where would you start? If you’re [rasp], the answer would be: “Spend a year trying to find the best way to make etched brass discs.” Luckily for us, he’s ready to share that information with the rest of the world. While it’s rather unlikely anyone else is working on this specific project, the methods he details for getting museum-quality results on brass are absolutely fascinating.

The process starts with sanding down the bare brass and applying a layer of clear packing tape to the metal. [rasp] then covers the …read more http://pje.fyi/QGnQ9W

Paul Jacob Evans

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Need Strength? It’s Modified Wood You Want!

Wood is surely one of the most versatile materials available. It can be found in a huge variety of colours and physical properties depending on the variety of the tree that grew it, and it has been fashioned into all conceivable devices, products, and structures over millenia. It’s not without shortcomings though, and one of the most obvious is that it can’t match the strength of some other materials. To carry large forces with a piece of wood that piece has to be made much larger than a corresponding piece of steel, something which is not a problem in a …read more http://pje.fyi/QG5MgD

Paul Jacob Evans

Home Brew Solar Cells for the Chemically Curious

The idea of making your own semiconductors from scratch would be more attractive if it weren’t for the expensive equipment and noxious chemicals required for silicon fabrication. But simple semiconductors can be cooked up at home without anything fancy, and they can actually yield pretty good results.

Granted, [Simplifier] has been working on the method detailed in the video below for about a year, and a look at his post on copper oxide thin-film solar cells reveals a meticulous approach to optimize everything. He started with regular window glass, heated over a propane burner and sprayed with a tin oxide …read more http://pje.fyi/QCvYvM

Paul Jacob Evans

DIY Graphene Putty Makes Super Sensitive Sensor

It is sort of an electronics rule 34 that if something occurs, someone needs to sense it. [Bblorgggg], for reasons that aren’t immediately obvious, needs to sense ants moving over trees. No kidding. How are you going to do that? His answer was to use graphene.

Actually, his super sensitive sensors mix graphene in Silly Putty, an unlikely combination that he tried after reading (on Hackaday, no less) about similar experiments at Trinity College resulting in Gputty. The Gputty was highly sensitive to pressure, and so it appears is his DIY version called Goophene. At Trinity they claimed to be …read more http://pje.fyi/QCTkJV

Paul Jacob Evans

A Salty Solution for a Dead Nexus 5X

If you’re an Android fan, there’s a good chance you’ve heard of the Nexus 5X. The last entry in Google’s line of low-cost Nexus development phones should have closed the program on a high note, or at the very least maintained the same standards of quality and reliability as its predecessor. But unfortunately, a well known design flaw in the Nexus 5X means that the hardware is essentially a time-bomb. There are far too many reports of these phones entering into an endless bootloop right around the one year mark to say it’s just a coincidence.

The general consensus seems …read more http://pje.fyi/QBWj52

Paul Jacob Evans

Microbalance Determines Alcohol Content

With the holiday season upon us, it is useful to be able to determine just how much (or how little) spiking the office party punch has received. [Russell Smith] shows how he tried to determine the proof level of booze using a microbalance made from an old-fashioned panel meter.

That might seem odd, but since alcohol evaporates faster than water, you can plot the change in evaporation rate if you have a good enough scale. That’s where the microbalance comes in. The idea is to weight down the needle of an old meter and measure the amount of current it …read more http://pje.fyi/Q73nhw

Paul Jacob Evans

Coffee, Conspiracy, and Citizen Science: An Introduction to Iodometry

I take coffee very seriously. It’s probably the most important meal of the day, and apparently the largest overall dietary source of antioxidants in the United States of America. Regardless of whether you believe antioxidants have a health effect (I’m skeptical), that’s interesting!

Unfortunately, industrially roasted and ground coffee is sometimes adulterated with a variety of unwanted ‘other stuff’: corn, soybeans, wheat husks, etc. Across Southeast Asia, there’s a lot of concern over food adulteration and safety in general, as the cost-driven nature of the market pushes a minority of vendors to dishonest business practices. Here in Vietnam, one of …read more http://pje.fyi/PyP6G1

Paul Jacob Evans