Exercise Bike Generator

I’ve always been impressed with exercise bike generator displays at renewable energy exhibits. So, a while back, when I saw a classic Schwinn exercise bike at the thrift store, I nabbed it with the plan to make it into an EXERCISE BIKE GENERATOR!

Earth Week is only a week away, and since our local eco-group is hosting a BIKE-THEMED event this year, I thought I’d “get in gear” and quick put together a bike generator.

I really already had all the parts needed. Mostly, that’s a bike and a permanent-magnet motor. Besides that, it’s just some scrap wood, a bolt, nuts and washers and a bungie-cord.

At the heart of the project is a 12V electric motor. I still had a few parts left over from my electric car conversion project, including the electric radiator fan. My electric car didn’t need an engine or radiator, so I set the fan motor off to the side for future use. I pulled it out for this project. First, I had to remove the plastic fins, which were practically cast in place. I managed to remove them, and get it down to an aluminum hub mounted on the motor shaft.

Next, I cut a scrap of plywood, and used a hole-saw to make a hole in it big enough for the motor to sit in. I put the motor in place, and attached it with three small wood screws.

I drilled a 3/8″ hole through the corner of the plywood, and ran a long bolt through it into the front frame of the cycle. That way, I was able to test alignment of the motor shaft with the front wheel. It matched up pretty well. I would just need to smooth out the hub on the driveshaft and add a stabilizer and tensioner to the motor.

The hub on the driveshaft was bumpy, which made a lot of vibration on the exercise bike tire, and the gear ratio was just a hair off. If I could trim down the diameter of the hub a bit, it would smooth out the ride and allow me to pedal just a tad slower while at the right speed for 12V charging.

I did NOT have a lathe handy, so I thought it would be pretty tough to smooth out the hub. That’s when I realized there was nothing stopping me from JUST SPINNING THE MOTOR. So, I clamped the motor down to a work-table, grabbed the jumper cables from my truck and a 12V battery, and just spun-up the motor! I then used an angle-grinder (with a flapper disc) to smooth down the hub, and reduce its diameter a bit. Because it was spinning at high speed, it came out perfectly concentric and balanced. Not bad for an improvised “poor-man’s lathe”.


I put the motor back onto the cycle and added another piece of plywood opposite of it and a cross-piece to made a basic box shape. This holds the motor solid and lets it swing up and down but NOT side to side.

At that point, all that was left was a tensioner. I added a drywall screw to the wood and attached a bungie-cord from it to the base of the cycle. That applies a light, but steady, force of the motor against the wheel.

I clipped my volt-meter to the two wires coming off the motor and pedaled. Sure enough, it was pretty easy to pedal at a rate that gave me an output voltage between 12-14 volts, what’s needed to charge a 12V battery.

After that, I hooked it up to my Fenix Intl. Ready Set – a 12V battery with built-in charge control and 12V and 5 outputs. It also has a nice charge indicator light on it, and universal power input on the back, meaning I could just run my bare wires straight in and tighten them down without even needing tools. I then only have to pedal fast enough until the “Now Charging” light comes on to know what speed I need to maintain for 12V charging.

This isn’t exactly a fancy or high-power exercise bike set-up, but it sure was easy to build. I did some testing, and it’s simple to output 10 watts of energy. That’s just about perfect for charging an iPad. That also means it’s pretty easy to do something like designing a setup where if you want to watch a movie on the iPad, you have to pedal to make it happen!

Just think how much more fit the average American would be if we all had to pedal to watch TV!

This project took about an afternoon of work and cost me $8, the cost of the cycle at the thrift store. I already had the motor, nuts and bolts, bungie-cord and scraps of wood. All in all a nice little weekend project.

Have you built your own exercise bike generator? What do you power with it? What did you do different on your design? Let us know!

Take care, and keep pedaling!


Remote-Controlled LED Room Lighting

This gallery contains 4 photos.

My apartment has sub-par to poor lighting.  Combine that with our lease’s “no painting walls” policy and you’ve got a one-way ticket to Drab-ville.  Many moons ago I planned to replace the over-cabinet lighting in our kitchen with RGB LEDs controlled by Arduino, but I never found the motivation to actually do it.  Then one […]

Snow-Globe Video

Just a minor update here from my recent Snow-Globe blog entry ( http://milwaukeemakerspace.org/2012/12/custom-snow-globe/ )

I made two VIDEOS about the snow-globe. The first is just a brief video showing the finished project. The second video is a longer “How-To” which includes some video, but is mostly a photo slide-show of all the steps I took to create the project.

For an in-depth step-by-step of how I built the project, check out the info I posted on Instructables. http://www.instructables.com/id/Custom-Singing-Snow-Globe/


Custom Snow Globe


Well, I’ve been slaving away on creating a unique X-mas gift for my wife and two-year old daughter, and I think I got it right. They loved it!

I’m talking about a Custom Snow Globe!

A while back, I was working in the driveway on a styrofoam project. Of course, that white stryrofoam dust gets static-charged and STICKS TO EVERYTHING. I also found that the best tool for cutting it was my wife’s kitchen electric carving knife. When I headed inside to take a break and warm up, I was COVERED with styrofoam. My two-year-old girl looked up at me and squeeled “Daddy a Snowman!”.

Indeed I was. I imagined myself inside a snow-globe with styrofoam swirling around me like a snowstorm. But could I actually BUILD a snowglobe that would match my imagination?

I started looking at every snow globe I could find and set to work building one. I looked around and found a glass dome, used for light fixtures. I got two of them, and gave one to my brother-in-law, who is a clay artist, among other things, and commissioned him to make a caricature of me. Since he had one globe, and I had the other, he could make a figure that would fit inside the globe, and I could do the woodworking on the base, and insure that the globe fit that.

I headed to the local cabinet shop and talked to old high-school class-mate Steve about what wood to use for a base. He gave me a maple block, and I grabbed some scrap maple from the bin to practice cuts and routering on. At my Dad’s back-of-the-garage shop, I experimented with routing, until I could get it right, and routed a circle for the base of the glass globe, cut the wood base to length and cut a 45-degree bevel on the top edge, and routed a pocket in the bottom for the electronics.

I wanted to make a “singing” snow-globe, so I bought a singing greeting card at the Hallmark store, and then dissected it for parts. The electronics were then mounted on the bottom of the  wood base, along with a custom switch.

I headed to the Milwaukee Makerspace to use the laser-cutter.

Using the vector graphics program on the laser’s computer, I laid out an inscription for both the top and bottom of the snow globe base. I practiced on a piece of paper, and then when I actually focused the laser properly and had everything else figured out, I wood-burned the maple block, front and back.

I also used a solder station to add the momentary on switch to the greeting card electronics, so that the song would play whenever the globe was picked up to shake up the snow.

Next, was clear-coating the figure and the wood base. I used “Parks Super-Glaze”, a two-part epoxy clear coat used for bars, to completely seal and waterproof both the figure and the base, as well as to permanently attach the figure to the base.

Then, it was a matter to holding the globe upside down, filling it with water, filling the routed circular grove of the base with silicon glue, and flipping the figure and base, upside-down, into the dome of water. Once it was cured, the snow-globe can be flipped right-side-up, gift-wrapped, and put under the tree!

I’m glad to say that the project turned out just great! It was a bit of a stretch to my skill-set, so THANK YOU to the people who gave me a hand with it. Nothing quite like a project that runs the gamut from sculpture to wood-working, electronics, glass, water, laser-engraving, and more! But that’s how we grow… by stretching a little bit more every time!

Merry X-mas

From Ben the Snowman.

Halloween Skull Project

I want to open my first blog post with a statement that continues to impress me: Milwaukee Makerspace is a wonderful place! I mostly show up for the free meetings.  MMS provides an excellent environment to be social, to learn (happens every time I go!), to teach (when I can!), and to get the creative juices flowing.

I had recently started working with Arduino (after a failed run at Microchip’s PIC series of microcontrollers), and was making progress quickly.  I learned how to read infrared remote control codes, how to use an infrared motion sensor, and how to control servos. What I did not have, was a sense of direction as to where to go with all of this!

After listening to the Bay View Neighborhood Associate pitch their idea of MMS helping with the Pumpkin Pavilion, and listening to Royce Pipkins describe his idea of animatronic pumpkins singing along to a song, I was struck with my own idea: an animatronic skull.

Thus, it was born!

http://vimeo.com/55121596 <- Link to the video

I’ll post more details in a following post about how I built this guy. :)

Many thanks to Royce, Tom G., and Ed C. for their help on this project!


A microtome is a device for slicing very thin cross-sections of stuff, in order to view them under a microscope.  Commercial ones are available, but they cost upwards of $50.  There is a classic DIY solution, but it involves a piece of old technology — a wooden spool for thread.  Outside of antique stores, those aren’t common.  Plastic ones tend to be hollow, meaning there’s no guide surface for the razor blade; and the razor is likely to shave the plastic instead of slide across it.  Gluing a washer to the plastic spool would address both of those problems.  But there is very little gluing surface on the end of a hollow plastic spool.



Lacking a wooden spool, I cut a cube off the end of some scrap 2×2 and bored a slightly-oversize hole through it.  Using Gorilla Glue, I attached a flanged nut and a flat washer to opposite ends of the hole.  Before the glue set, I used the bolt to center and clamp them over the hole.  Gorilla Glue expands 30% as it sets.  To avoid permanently gluing the bolt into the body, I carefully removed it after a few minutes.  You can see glue in the threads adjacent to the bolt, in the image at right.  A few minutes with a wire brush cleaned the bolt threads.






Lastly, I flattened and polished the washer on a lapping plate.  The edge of the washer-hole was rough, and glue had expanded out of the hole and onto the surface.

The nut & bolt are 1/4 x 20.  One complete turn is 1/20″.  So a quarter-turn should be 0.0125″ thin.  That, and a fresh razor blade, should make slices thin-enough for a microscope.

Magic Mirror Theater Prop

My sister is a Theater Manager at the Patel Conservatory in Tampa, FL.  About two weeks ago she texted me and asked if I could make her a prop she needed for an upcoming production.  “How keen would you be on making me a mirror for “Beauty and The Beast,” she said.  “They want a mirror that lights up and sparkles like the one from the movie.” Even with limited experience just tinkering around, I knew I could do something fairly easily, so I agreed and got to work.

I combined two different circuits (a 555 timer to flash and a RC circuit to fade) and built a wooden frame with acrylic plates for the front and back.  The wood and plastic were CNC-milled, then sanded and painted before the electronics were installed and glued into place.

The result was a fairly decent-looking, shiny, light-up hand mirror with a small thumb button on the right side that flashes 16 bright green LEDs when pressed.  It all runs off a single 9-volt battery and the back can be unscrewed to replace it should it ever die.

Total build time from start to finish was probably close to 15 hours over the course of one week.  The play was Thursday, July 19th and from what I’ve heard, it was a great success.  I’ll add pictures from the performance if I get some.

Android Blue or iOS Purple? Update on the OOMA project

The Object Of My Affection Lamp   I thought I would jump in and blog on my current progress at the Makerspace with a lamp called OOMA, or The Object Of My Affection. It’s a lamp that is shaped like a GPS Navigation pin that rotates to always points toward the one you love… as long as they allow you access to their Google Latitude account :). I am finalizing hardware designs and now moving into writing the software and how it talks to the Internet.

Initially I would have waived it off as using WiFi, or Ethernet, but work on another project (Marco) has illuminated several obstacles over multiple use cases (configuring Wi-Fi, closed networks, IP addresses); instead I think the approach will be to opt over USB (via Arduino Leonardo). I figure, if people will load up a coffee cup heater or foam missile launcher to USB, than there is no issue with port scarcity.

It’s not a lamp without light, and at some point OOMA will light up in either Android Blue, or iPhone Purple. Lighting the lamp will, however, have to relegated to a v.2 build, due to some complexity in the diffusion of light in such a cramped space. Additionally, I’d like to investigate EL panels to light it up.

Finally, I am coming up on the decision to be a DIY offering, or to design it to be marketable – do I build as a one off and just offer the blueprints to others or build an end-to-end consumer solution complete with potentially an NFC tag to tap and pair a user and their lamp.

MegaMax 3D Printer

MegaMax 3D Printer

MegaMax 3D printer based on MendelMax but bigger and minus plastic parts.

This is my on-going project at the Milwaukee Makerspace.  It is a 3D extruded plastic printer with about 1 cuft build envelope.  I want to print life-size human skulls (among other things) from CT scan data.  The printer is made mostly from salvaged parts and materials so the cost has been very low.  When it’s finished it will have a heated 12″x12″ bed (13″x13″ if I can find an aluminum plate that big) and dual extruder so it can print in two colors.

I have learned a lot on this project- some things that work and others that don’t work so well, and how to use a milling machine to drill holes precisely and square the ends of the 8020 extrusion pieces used to build up the frame of the machine.

I could not have done any of this without access to the people, materials, and tools at Milwaukee Makerspace.  Every time I go there to do some work on this project someone says something that gives me new ideas for improvements to the design.   I frequently find materials and parts left for me on the machine’s cart by other members who know what I’m trying to do.  If you have a project idea find your local Makerspace and get busy- there is nothing that will get your creative juices flowing like being around a bunch of people with similar interests and different skills and experience!