2020-03-06 (F) Weekly Summary

This article came from a magnet retailer's blog that I've used in the past. They showed how a magnet and coiled wire could capture and reproduce sound. With this in mind, a speaker is also a microphone, and more generally, a sound transducer. The folks at this site always do a thorough job of demonstrating magnetic principles.

The electric knife project continued with the focus on 3D printing. I designed a series of four units that would each hold a component, starting with the battery, then the high voltage converter, a switch, and an adapter for the knife blade.
3D model for holding parts

The spine of the design was a 1/4" (6mm) bolt along the bottom. Unfortunately, the models were too flimsy, and maybe another bolt channel would have strengthened it, but it seemed like printing the whole model was going to be foolish.
Printed models

At the other end of the durability spectrum, I started experimenting with an all-metal handle. The first try was a pair of metal bars, two sets actually. They would bolt together with the handle fastened to one end.
Metal bars

I needed to make sure that a metal handle wouldn't shock the user, so I tested if I could clamp a stun gun between my metal bars. This was also a test to see if we could churn out electric knives with minimal steps, and this method kept the frame intact, so there our button and case were settled.
Taser + knife

I extended the high voltage wires from the stun gun to the aluminum tape on the rubber blade and demonstrated the usefulness of the design. It was fiendishly difficult to hold, so I must keep working for a comfortable design.
I mean, it works

To streamline the handle, I took the high voltage converter out of the stun gun and added an 18650 battery holder. The most obvious problem with this design is the voltage transformer that hangs out the bottom. I think I can cover it, but it is not convenient.
Fits in the hand

The rest of the summary posts have been arranged by date.

First time here?

Completed projects from year 1
Completed projects from year 2
Completed projects from year 3
Completed projects from year 4
Completed projects from year 5
Completed projects from year 6

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