Some Homemade Wind Generator Experiments

February 18, 2022

Lately I’ve been building some small wind generators out of scrap material. So far they haven’t been all that efficient (or even very sturdy). Eventually I’d like to get something that will hold up to the local weather and generate a little power. It doesn’t have to be much power, just enough to charge a phone or run a small device like a Wifi hotspot would be fine.

The first design was a traditional (sort of) windmill. The blades are from an old ceiling fan, so it’s not optimized for wind power the way real airfoils would be. The generator/alternator was an old electric drill, with a 90-degree adapter as the pivot and mechanical power transfer.

This one worked OK, but didn’t hold up to the weather and I still haven’t found all the pieces under the snow!

Version two is a vertical-axis turbine made from old plastic barrels and a scooter motor. It’s currently installed at Sandland and may or may not survive until my next visit!

Version 3, if and when I get around to it, might be a combination of the horizontal blades, a better alternator, and a slip ring for pivoting. That last bit is what’s hard to DIY, so I may just have to buy a real one.


DIY Underwater Exploration

January 25, 2022

Building a small submarine or ROV is something I’ve been meaning to do for years. I finally got around to throwing some parts together, and it turned out surprisingly functional. There are still a few kinks to iron out, but this contraption of PVC pipe and surplus electronics actually works!

The outer frame is made of PVC pipe, holding a central electronics box with the navigation camera and thrusters. The navcam feeds live video back to a screen on the control panel (when it’s working!). For better quality video, there’s a GoPro mount on the front. Lights on the front let the cameras see better underwater or in dark caves (where I’ve mostly been testing it so far).

The first cave test (above) was admittedly pretty low-stakes. The water in this cave is all pretty shallow and if I got the thing stuck I could have just waded out to retrieve it. However, I wanted to verify operations for a slightly more challenging cave (below).

I’m hoping to use this in a few more places (maybe when the weather is warmer and the thrusters don’t ice up!). I’ll probably also fix a few of the broken bits and adjust things further, so look for more on the ROV project in the future!


Short Attention Span Videos

January 25, 2022

Youtube has really been pushing its new-ish “#shorts” feature, probably in an attempt to compete with a certain vertical-video app. Since they keep pushing me to do it, here are some short versions of my popular videos (plus a few short-only features!).


Handheld Capacitive Scanner / Wall “X-Ray”

December 2, 2021

Recently I came across a project to turn the Raspberry Pi touchscreen into a 2D capacitive imager. The creator showed how it could be used to see ghostly, pixelated images of wood and metal elements within a sheetrock wall. As someone with a “complicated” house, I struggle with traditional stud finders. I thought that something like this looked pretty cool, and potentially useful! My version of this project is in the video below:

For the hardware side of this, I used the following:

-Raspberry Pi 3 B (Other models might work, but this is the same as the original project used).
-Official Raspberry Pi 7″ Touchscreen
(Note, only older ones with the FT5406 chip will work!)
-Generic 7″ HDMI touchscreen
-Screen protector for above (since we’ll be sliding it on surfaces)
-(9.0″ x 5.9″ x 3.4″) ABS project enclosure (other sizes might work).
-Right-angle HDMI adapters (upwards 90).
-USB extensions x2
-Mini-USB extension (for charging)
-USB battery pack with two high-power output ports.
-Square U-bolts (x2) for handles
-Momentary push button with jumper cables for shutdown trigger.

I used Rasbian Stretch as the OS on the Pi. It seemd to be the right age to work with the 2016 code, but still new enough to work with the Pi 3B. I changed the /boot/config.txt and raspi-config settings as described on Optisimon’s page to enable I2C and disable touch input from the bottom screen. I also added a line to config.txt enabling the shutdown overlay. I also updated the console version of raspi-config and enabled Full KMS (Under GL settings) to get the external HDMI screen to take priority over the displayport screen.

For the software, I used Optisimon’s code, with a few tweaks as follows:

-In FT5406.hpp, changed line 83 to “for (int rowAddr = rows; rowAddr > 0; rowAddr–)”
-In SDLEventHandler.hpp, changed line 55 to “_zoom = std::min(50, _zoom + 1);”

(These changes were for my preferred use and display style. The first reverses the scan order so the image is the same horizontal orientation as the screen on the back. The second change increases the max zoom to fit my display screen, and might not work with all screens.)

To install the code I did the following (these steps may be obvious to others, but they weren’t all obvious to me!):
-sudo apt-get update
-sudo apt-get upgrade
-sudo apt-get install xdotool
(You can also install i2c-tools, or the prepare step below will do it for you)
-“make prepare” from within ft5406-capacitive-touch/CapacitanceVisualizer
-“make install” from same directory
(If any changes are made and you need to recompile, you’ll also need to make a
change to “main.cpp” and then make again).
-I could then run CapacitanceVisualizer to display the scan.

For ease of use, I made a shell script (“launch.sh”) that called the program and maxed out the zoom, as follows:

“!/bin/sh
/home/pi/ft5406-capacitive-touch/CapacitanceVisualizer/CapacitanceVisualizer &
sleep 10
xdotool search –name CapacitanceVisualizer key F11 F1 KP_Add KP_Add KP_Add KP_Add KP_Add KP_Add KP_Add KP_Add KP_Add KP_Add KP_Add KP_Add KP_Add KP_Add KP_Add KP_Add KP_Add KP_Add KP_Add KP_Add KP_Add KP_Add KP_Add KP_Add KP_Add KP_Add KP_Add KP_Add KP_Add KP_Add KP_Add KP_Add KP_Add KP_Add KP_Add KP_Add KP_Add KP_Add KP_Add KP_Add KP_Add”

(Yes, I realize there are probably less horrible ways to do this, I just don’t know what they are!)

I also made a .desktop shortcut and placed it in /etc/xdg/autostart, with the following contents:
[Desktop Entry]
Type=Application
Encoding= UTF-8
Name= CapacitanceVisualizer
Exec=/home/pi/launch.sh
StartupNotify=true

With this setup, I can turn on the USB battery pack, and the scanner box boots up, autoruns CapacitanceVisualizer, goes full screen, and removes the background noise, all without any further input from me. I have some USB extensions to the outside of the case, so I can connect a keyboard / mouse if desired, but for the intended use of this device, I shouldn’t really need to.

Since Raspberry Pi is too cheap to have an on/off switch, I connected the pushbutton to GPIO pin 21 and the adjacent ground, and added the following to the end of /boot/config.txt:
dtoverlay=gpio-shutdown,gpio_pin=21

I might add another physical button tied to the GPIO to send an F1 keypress for further background noise reduction.

This write-up is the “short” version of my efforts. I ran into various problems and hiccups along the way, possibly related to the mishmash of official and cheap imported hardware I was using, or the fact that this whole project relies on unsupported, undocumented features well outside the intended use of the hardware. I also ran into some of the typical Raspberry Pi “quirks” like refusing to boot for random reasons, flipping screen orientation, etc. My video on the project was at least twice as long before I edited out all the dead ends and failures!

Here are some additional resources and background info on this project:
Optisimon’s website on the original project
Github code, also by Optisimon
Capacitive sensing from Wikipedia.
Hackaday article on the original project.
2006 research paper on capacitive imaging.
Electrical Capacitance Tomography (industrial scanning technique)




(Starting to) Re-assemble the Fast Food Playland!

October 7, 2021

In my latest Saveitforparts video, we’ve begun putting together the playground structure that Carl picked up free at an abandoned fast food restaurant (with permission!). It’s a slow process and probably won’t get finished this year, but at least we’re making progress on it!

To answer some of the most common questions:

-Yes we think it’s UV resistant (according to the manufacturer). Here are some outdoor installations from the same company:
https://i.redd.it/hmnuareh2j571.jpg
https://s3-media0.fl.yelpcdn.com/bphoto/filX-3VIJR0TWPE2FmmA-w/o.jpg

-No we probably won’t re-assemble it exactly the way it was. We already changed the design slightly.

-Nothing *too* gross was found inside, other than some fossilized french fries 😛

-Yes we’re pretty confident we’ll make progress on this. After all, we did move a monorail to Sandland!


The Government Hates This One Weird Boat

September 30, 2021

I’ll probably get docked on search results for the clickbaity title, but I couldn’t think of anything more appropriate for this project!

In part one (first video), I built a homemade tugboat by combining some foam and a trolling motor with a plastic “Tuggy” sandbox. In part 2 (second video), we find out why this isn’t considered “homemade” and can’t be legally registered as a boat. (However, barrels and pallets thrown together can be a “homemade boat”, because reasons).


Mississippi River(house)boat Adventures!

September 28, 2021

I spent a lot of last summer poking at an old boat with the intention of fixing it up, adding a cabin, and doing some Mississippi River overnight trips. That boat never really got going, and I’ve since bought a better one. However, in the meantime I was invited to help move an even bigger boat up the river! Apparently my background in Alaskan fishing and duct-taping kayaks together translate into being a river pilot!

This boat is a 1980s Gibson, about 42ft long and powered by two gas engines. As expected with a used 1980s boat it had a few hiccups, and my duct-taping skills did come in handy! We started the trip in Lansing (IA) where the new owners bought the boat. Over the course of several days, we moved it up the river to Saint Paul (MN). I split the trip into several installments since there’s so much to see!

And here’s a timelapse of (nearly) the whole trip, minus the times my GoPro overheated (I have an older one that’s prone to that, sorry!).


Another Dumb Boat Thing

September 27, 2021

Something compels me to make boats out of everything. As such, when I picked up a strange homemade motorized bike at an auction, my first thought wasn’t about biking. It was about “how do I make this float?”

After a lot of messing around with an old surfboard and some scrap materials, I got the bike to float! It doesn’t actually move very fast, unfortunately the little wheels just don’t push enough water. This idea might come back again in the future, but for now, here’s my first foray into amphibious surfbiking:

For those of us with ADHD, here’s the (very) short version from Youtube’s new attempt to enter the short format vertical video market:


The Ultimate Man Cave?

September 26, 2021

Forget big screen TVs, pool tables, and bad taxidermy, how about a homemade bar in an actual* cave?

*Technically it’s a mine, since it’s an artificial tunnel/cavern that I’m digging out.

Anyway, Jim from Sandland has kindly allowed me to explore my inner mole man by excavating a small bar / saloon / speakeasy in the sandstone bedrock. This won’t be a commercial operation or open to the public, it’s just a fun place to hang out! (And before you spam the comments with “how’s the air” or “will this collapse”, scroll down to the follow-up videos where I address those common questions!)


Episode 7: A New Boat!

September 24, 2021

Since picking up a free 1970s tri-hull boat last year, I’ve been struggling with getting it running and usable. As with many of my older engines, this was a never-ending process of fighting carburetors, timing, ignition, etc. The old outboard motor took so much time and attention that I never got around to doing any interesting mods on the boat, like building a cabin or installing fun gadgets.

Well, I finally gave up and got a NEW boat! And by new, er, I mean, even older! This one is a 1962 Dorsett Catalina, with a (supposedly more modern) V8 engine and a jet drive! This one has had it’s share of repairs and upgrades as well, but at least it runs and I’ve actually gotten it to go fast! See the video above for “Part 1” of the jet boat project, or skip to the one below for actual “going fast” footage (starts around 8min in).

Boat season is winding down a bit in Minnesota as we get into fall, but there are a lot of future projects (and hopefully, trips!) planned for this boat!