COVID Isolation Project #1 - Plane and Chisel Sharpening Jig

Due to COVID-19 and Social Isolation, to stay busy I’ve been trying to finish up a slew of projects that have been on my mind and some that I started but haven't finished yet due to other more urgent issues.  Some of these are very practical, some are experimental, others are likely a little silly or just for building a certain skill (Learning by making).

My first project, which I completed over the weekend is a jig for sharpening hy hand planes and chisels.  It's one piece that holds my wet stone and stops for setting blades in the xxx for standard sharpening angles.  The base is Baltic Birch 1/2" plywood.  My goal was to keep the setup as compact as possible. I used 1/2" square dowels to surround and hold the wet stone in place, these were clamped and glued in place. After the glue was dry I applied multiple coats of Polyurethane just to minimize water damage to the wood from the wet stone (water resistant but not water proof).

After the multiple coats of Polyurethane were finished drying I screwed down the right angle aluminum extrusion pieces as end stops for the 25 and 30 degree angles for chisel and plane blades.

Supplies

• 1/2” square dowel
• Baltic birch 1/2” plywood
• 1/2” right angle aluminum extrusion
• 8 x #6 1/2” screws
• Wood Glue
• Polyurethane

 Tools

• Saw
• Screwdriver
• Clamps 
• Ruler
• Right angle, 1-2-3 blocks or something else to align the blade stops

Heating element testing

I decided that I would finally test a 10cm length of 36 AWG nichrome wire with a current limited supply of varying voltages.  Since my windmill generates under 1 Amp of electricity I decided to use an LM317 integrated circuit to fix the current at a max of 220mA.  I put an LM317 in a bread board and attached its output to a 10cm length of 36 AWG nichrome wire (from the hair curler heating element).  Below is the circuit diagram for my LM317 set to limit current to 220mA:

Using the LM317 as a current limiter

Need to connect the 3 terminal chip as below:

     pic

To calculate the resistance that you need to limit the current to what you want:

     formula

In an effort to maximize the effectiveness of the heating element I decided to test different thicknesses (or gauges - higher the gauge thinner the wire) of Nichrome wire to see which would work best (produce the most heat with the power produced by the windmill - just under 2 watts). With this in mind I ordered 40 and 38 AWG Nichrome wire from Jacobs Online . They mainly sell Nichrome wire for making foam cutters and igniters for model rockets (the larger scale rockets). They are fairly inexpensive since you can order lengths as short as 10 feet – for $6 I got 10 feet of each of the 2 sizes I mentioned before (if I had wanted 100 feet of each I think it would have only cost me around $12 – better deal but I just don't want all the excess around).

Some basic notes on Nichrome wire:

• higher gauge (thinner) = higher resistance per unit length and heats up at lower power (less current)
• coiled wire produces higher temps than straight wire (with the same voltage and current)

More in depth info on nichrome wire take a look at the Wikipedia Page for Nichrome Wire

Resistivity of 1 foot straight Nichrome wire at room temperature:

AWG Ohms

40       70.2

38       42.2

36       27.0

Need some type of temperature resistant insulation between the wire  and the aluminum casing to prevent shorting out the current to the wire (do not want the wire in direct contact with the aluminum since it also conducts electricity). Insulation: Mica sheet, fiber glass fabric (welding supply, car body work with Bondo)

Ni-chrome Wire Calculator

Nichrome Wire Calculator

Gives you some ideas of what you need even though the lowest temperature on the calculator is 400 degrees Fahrenheit.

If average wind speed is 15mph – which produces 220mA at about 9volts. That gives us our average power available. Ohms law states V=IR rearranging we get R=V/I:

R = 9v/0.220Amps

R = 40.9 Ohms

So, with the windmill running with a 15mph wind producing 9 volts with 220mA (which is just under 2 wattS – P=9v*0.22A) if we use a length of wire with 40.9 ohms resistance it should use up all the power. Yes, I know its not perfect reasoning since resistance increases with increasing temperature in the wire but I'm just trying to get an idea of what I need before I begin trying things.

Project Neurofeedback: Going a bit further with EEG hacking (Part 3 - smaller unit)

Remove the TGAM1 Board

(This step is optional – I just wanted to remove parts that are not actually used and free up space. If you do this then you also need too add a 3.3v regulator circuit to the power supply, same as I did)
Separate the TGAM1 Board from the main board in the Mindflex Headset. This reduces the size significantly – Bluetooth board will fit with room to spare.

• Cut headers attaching boards
  
• Desolder and remove cut header pins
  
• Keep connections to (Header P1 connections on data-sheet)
  
  • Ground (electrode)
    
  • Reference (electrode)
    
  • EEG (electrode)
    

Adding a 3.3v regulator, with filter caps, to the power supply (3 x 1.5v AAA batteries in series).
3.3v regulator board (strip board)

• linear voltage regulator
  
• filter caps

SHOW-AND-TELL LIVE VIDEO! 9/6/17 #showandtell @adafruit #adafruit

Project viEwMotion

The goal of viEwMotion is to facilitate communication for individuals who have difficulty expressing emotions due to inherent neurologic issues like Autism, Parkinsons, etc (conditions that make it hard express emotion outwardly and as a result for others to read emotion expressed by the effected individual).  viEwMotion will do this by interpreting real time physiological data acquired from a wristband which is then processed by a single board computer and displayed to allow others to see the persons emotional state.  This will have a profound effect on the ability of people to communicate effectively - changing how they experience and interact with the world around them (in effect changing the world for them and those they interact with).
viEwMotion is a wearable device (worn on the wrist like a watch), that monitors and transmits data to a mini computer which interprets the data and outputs it to a display worn by the individual.

Voight-Kampff LED Bar-graphs

Working out the LED bar graphs on the Voight-Kampff machine:

Project Voight-Kampff

My objective is to build a functional Voight-Kampff machine from the classic Sci-Fi Movie Blade Runner. 

Leon's test :

Rachel's test:

Currently, I'm working on developing the software, integration of sensors and the actual body of the machine.

I currently have this project entered in the Hackaday Sci-Fi Contest  (Voight-Kampff Project Page) and I plan to exhibit it at the Chicago 2017 Maker Faire.

I have much of the mechanics (arm raise, extension, and rotation of the eye sensor) worked out using servos and micro-controllers.

My current design calls for using a Raspberry Pi as the central processor for the VK. The sensors that I'm currently working on integrating are:

• Melexis MLX90614 Non-contact Temperature sensor (for Blush response)
• Raspberry Pi NoIR Camera Board v2
  • using software adapted from PyGaze to measure pupil dilation/constriction
• Separate hand held module for test subject containing:
  • MAX30100 pulse ox sensor
  • Galvanic Skin Response Sensor

I aim to have it all contained in the classic VK machine with read outs from the sensors going to the 3 separate monitors (and the 2 LED Bar Graphs).