Oh nice I will read up and check some of these out, let me know if you want any help with a cover.
I thought it would be fun to make some “name thingies” for my co-workers. Here’s the one that I created for Marcia:
I had this 3D printed in laser-sintered nylon and dyed purple:
The 1" x 1" letters unfold to make the name thingie:
In a former life (circa 1985), I used CAD/CNC to machine a 2" egg out of aluminum. It was created with a 3rd order 2-point B-Spline rotated about the axis. @splicer9’s query about splitting an egg mold got me interested again.
Thanks to Nobuo Yamamoto, I located these parametric equations for an egg:
x = Lcos(u) + (A + Bcos(u))cos(u)
y = (A + Bcos(u))sin(u)
Transposing them into Ruby formatted expressions gives this:
x = 15.0 * Math.cos(u) + (30.0 + 15.0 * Math.cos(u)) * Math.cos(u)
y = (30.0 + 15.0 * Math.cos(u)) * Math.sin(u)
where L = 15, A = 30, and B = 15.
Here’s a video using these parameters with U-V PolyGen:
And the model:
I cut the egg apart and made the classic wooden puzzle out of it:
egg_puzzle_3d.skp (2.1 MB)
I was playing around with importing various graphic designs and came across this pendant of the Labyrinth at Chartres Cathedral:
I created a similar design and sized it so that you could use a BB to roll around the path to get to the center:
However, it ended up being more than 10" in diameter and would cost me almost $300 to have it printed by Shapeways:
I thought I would attach the STL file in case someone would like to print it (or rout it) on their own machine
chartres_labyrinth.stl (1.4 MB)
My wife has always had this mild obsession with humidity. Over the years, I’ve bought her several humidity gauges, but they never seem to work very well. The last one shows about 50% when it’s raining and around 30% when it’s statically evident that the humidity is near zero. I recently had a project that needed some sort of network savvy interface and I ended up buying two NodeMCU ESP8266 development boards (one for a spare). With the addition of some software, a DHT11 temperature/humidity sensor, and some jumper wires, I ended up with this simple creation:
Plugged into a USB power source, it attaches to my WiFi network and hosts its own web-server. Now my wife can click on a bookmark in her browser and get this:
Total cost was about $15 ($9 for the ESP8266, $4 for the DHT11, and $2 for the breadboard). The sole downside is that the humidity is only accurate to +/- 4% and the range is limited to 20%-90% (I neglected to mention this to my wife, however).
Is it hollow? Would making it hollow reduce the costs substantially? You could add interior supports to strengthen it.
It had more material than needed … thanks to your suggestion, I hollowed it out to leave 0.040" thick walls and reduced the overall thickness from 0.400" to 0.240". I left the outer ring solid for stability. This cut the cost by almost exactly 50%:
In addition to the WiFi temperature/humidity gauge, I also built one using an LCD display and a different version of the DHT sensor:
I don’t normally promote or recommend products to anyone, but I treated myself to an Arduino experimenter’s kit that is simply amazing in what it includes for the price. It has everything you need (battery included) to learn how to interface a wide variety of sensors to an Arduino and write the code to make it work. Lot’s of web-support with step-by-steps and how-to’s … comes with a DVD full of example code and documentation. Rather than provide a URL, search for Elegoo EL-KIT-003 UNO Project Super Starter Kit (should be $35.00). Note that this is not a true Arduino, but a compatible UNO based on the ATMEGA328P controller.
When I was about 10, my grandmother gave me a book called “Everyday Weather and How It Works.” In addition to explaining all about humidity, it had instructions for three different projects to build a humidity gauge: (1) using a long hair wrapped around a toothpick pointer (2) using a thermometer as a “sling psychrometer” and (3) using a pair of thermometers with the bulb of one of them covered by a wick (like the one you show). It sticks in my mind because the book suggested using a piece of shoelace for the wick:
As luck would have it, I just happened to have a brand new pair of tennis shoes that had the perfect shoelace for this project. While I was thrilled with my creation, my mom was not terribly amused
The black fabric around the wet bulb is in fact a piece of cotton shoelace !