Electric Ice Scooter

DSC_0424

When I recently was at the thrift store and saw a pair of ice skates next to a kick-scooter, it got my mind going. “What would a scooter look like with skates in place of wheels!?”

The next time I was at the Makerspace, I saw my old electric scooter over on the Hack Rack. This was a scooter I originally rescued from a dumpster. Although it didn’t have batteries, just adding power and a little tinkering got it up and running again. A few of the EV Club and PowerWheels Racing guys played around with the scooter a bit, but eventually the controller got toasted, and who knows what happened to the front wheel.

Oh well, I’d be replacing that front wheel with an ice skate anyways.

Turns out that the heel of an ice skate is actually sturdy enough to drill right through and use as a mounting point. I simply  drilled through the skate, inserted a spacer, and then ran a 3/8″ bolt through the skate and the front fork of the scooter. I finished it off with a couple of washers and a nut.

Then next thing to fix was to get the  motor going again. Turns out that it’s a brushless motor. While I have a fair amount of experience now with BRUSHED motors, this was my first experience with brushless. I did a little research, and then ordered a 24V, 250 watt generic brushless controller from a mail-order scooter parts company. Unfortunately, it used a different style of throttle than what was already on the scooter, so I had to order a throttle to match.

Connecting the controller was pretty easy, three wires to the motor and the black and red one to power. I first bench-tested it with an old printer power supply, and once everything was working right, bit the bullet and bought a brand new pair of 12ah SLA batteries. The two batteries are wired in series, along with a 20 amp fuse, and then go to the controller.

I still needed a deck for the scooter. I dug through some scrap materials and found a pair of cabinet doors that were about the right size. I cut them down just a bit and bolted them to the scooter. I even re-mounted a cabinet door handle to have as an attachment point for towing a sled.

With that, I was ready to go for a test ride, so it was off to the lake. Once I was on the ice, I turned on the scooter and gave it a go! What fun! It really zipped along, but it was almost impossible to steer, as the back tire would slip right out from under me! Time for more traction!

I decided to make a spiked tire. I removed the rear wheel, then disassembled the two-part rim and removed the tire and inner tube. I stuck 1/2″ self-tapping, pan-head, sheet-metal screws through the tire from the inside, so that their points stuck out.DSC_0394 I evenly spaced out 24 screws and alternated them to be slightly off-center side to side. Next, I put some old scrap bicycle inner tube over them as a liner to protect the scooter tire inner-tube. After that, it was just a matter of reassembling everything.

Now for test #2 out  on the ice. Remembering how much it hurt to fall on the ice, I was prepared this time by wearing my motorcycle jacket (which has padding built-in) and my helmet. Good thing too, as I would learn while steering with one hand and holding a GoPro camera in the other…. (Note to self, keep both hands on handlebars at all times.)

Overall, the Ice Scooter works great! I still have a few little things to do on it. For example, the motor is running “sensor less”, and I’d like to learn about how brushless motors use the sensor system. I’d also like to get a small 24V dedicated charger. As it is right now, I have to remove the deck and manually charge with a little 12V charger.

From thrift store idea, to hack rack, to life on the ice, it’s always fun to see what you can do with just a little ingenuity. I hope you like this project. If you want to see more on it, please check out the write-up I did on Instructables. It’s even in a few contests there, and I’d love your vote!

Keep on Making,

-Ben

Open Source Ecology in Milwaukee

Open Source Ecology

Marcin Jakubowski, TED fellow & founder of Open Source Ecology, will be visiting Milwaukee and speaking at three public lectures on the topic of Social Entrepreneurship.

Open Source Ecology is a non-profit organization with the goal of designing 50 industrial machines that it takes to build a small, sustainable civilization with modern comforts. The idea is that true economic power can be unleashed in developing countries when they gain access to the CAD files, how-to videos and other engineering specs required to make tools to build houses, agricultural equipment, etc.

(We’ve got a few members who are huge fans of Open Source Ecology and the ideas behind it.)

Open Source Ecology

Here’s the details on the three lectures taking place:

MSOE Lecture
When: Tuesday, February 18th at 7pm
Where: 1025 N Broadway St. Milwaukee, WI 53202
Multi-Purpose Room, Campus Center Building, 3rd Floor
more info

UW-Milwaukee Lecture
When: Wednesday, February 19th at 12pm
Where: 2200 E. Kenwood Blvd. Milwaukee, WI 53201
ANSYS Institute for Industrial Innovation, EMS Building, 1st Floor
more info

Marquette University Lecture
When: Wednesday, February 19th at 8pm
Where: 1637 W Wisconsin Ave. Milwaukee, WI 53233
WI Energy Foundation Classroom, Engineering Hall, 2nd Floor
more info

And here’s a video of Marcin talking about Open Source Ecology:

Weekend Project: End Table

This weekend I made an end table for my living room.  Its in the style of two night stands I made, this one for the tool at hand contest, and this second one! The legs of this series of small tables are getting increasingly eccentric.  To build it, I started with three pieces of 2×12 lumber, and a 1/2″ diameter dowel rod.  I avoided using metal fasteners, and instead used only wood glue and 8 3″ long dowel pegs to attach the legs to ensure that sculpting the table with my chainsaw-blade-equipped angle grinder would be safe(r).  To save some labor with the grinder, I actually cut some of the zig-zag legs with a band saw first.  Even with the pre-cutting, I ended up making 1.5 cubic feet of wood chips and saw dust.

EndTable

PVC Musical Headboard Build

5 years old have many things in common. A penchant for poor personal volume control, meth-addict levels of energy, and an OCD like compulsion to make noise. Mine in particular has the “drummer” variant of that condition and so loves to bang on anything and everything. This affliction made manifest is the Blue Man Group, naturally his favorite musical group. So when he needed a new headboard for his bed, we decided to see what we could do let him exercise his inner Blue Man.

Materials were:

  •  4 pieces of  6’  long, 4 inch PVC
  •  4 pieces of 10’ long of 2 inch PVC.
  • 2 & ½ bags of 2 inch 90 degree elbows
  • You’ll eventually need PVC primer and glue as well once you’re ready to lock everything in place.
  • 2 3/8” hole drill bit. (Exterior diameter of 2 inch PVC is 2 3/8)

The math behind the right lengths for the right tones are pretty straight forward – I just followed the recommendation from a PVC instrument instructable by tallman1996 – there he explains:

“I got an equation from nate true that will give you the length of the pipe you need when you plug in the frequency: Tube Length (in) = (13300/(2*Frequency))+(Tube Diameter/2)

For the frequencies of the notes in the range of the piano go here: http://en.wikipedia.org/wiki/Piano_key_frequencies
My low note was number 16 (C2) in the list on the wikipedia page.”

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Drilling the holes through the 4 inch pipe was easy, just lay two parallel lines opposite each other on either side of the pipe and mark your drill holes on either side at equal distances from one end. The 2 3/8 hole bit went through easily but you had to keep it completely perpendicular to the pipe or it would jam. I highly recommend you use a drill with a torque setting so you don’t snap your wrist or have the pipe turn and crack you in the head when it jams. Don’t ask me how I know this.

Also, PVC power / flecks have amazing static cling powers so be aware that it’s rather messy.

Since I was worried about the pipe length hitting the ceiling and didn’t want a spaghetti mess of pipes on it I opted for a C3-C4 whole note scale with an extra C2 at the bottom for a nice low note.

It turned out well, we need to paint and glue the PVC together and drill the elbows to the lower cross member but even with the dry fit they stay together pretty well. With the 90 degree elbow on the end, he could continue to stick pipes on it and change or add notes if he’d like.

Paddles for now are just a pair of old flip-flops that will be modified to have handles. Any dense foam rubber will do.

This was also a great excuse to try out my new GoPro 3 on Time Lapse, so here is a video I did of the build:

 

Our 4′ X 8′ CNC Router takes a step forward!

With a lot of hard work from Ed H. and Steve P. our 4′ x 8′ CNC router has achieved a milestone, instead of the X axis sitting on the ground it has taken a leap up and is now mounted, ready for the Y and Z axis to be mounted to it along with the electronics and motion control.

beam mounted

The X-axis is ready to be milled here.

The X-axis is ready to be milled here.

2014 RPM Challenge: Accepted!

Today is the first day the 2014 RPM Challenge, which is the National Novel Writing Month of music!  The goal of the RPM challenge is to compose and record an entire album during the month of February! I accepted the challenge by dusting off my Cacophonator and Mohogonator, and got to work making music after dinner today. As today also marks the 50th anniversary of the Beatles invasion, this project drew inspiration from the Beatles’ back catalog!

RPM_Challenge

I used the dynamic duo of Cacophonator and Mohogonator with Auditionator (i.e. Adobe Audition) to record a session for about 12 minutes at a blazing fast 192kHz sample rate.  After chopping the recording into individual tracks, I digitally slowed them down to the customary rate of 44.1kHz, thereby expanding the work to its final ~45 minute length.  For inspiration while I was recording, I listened to Beatles songs sped up to 435% (which is 192/44.1) of their customary speed.  My tracks needed a bit of post-processing: on some of them I chose to bump the pitch back up an octave or two and add “Beatle Fades” to the beginning and end.  Anyway, within twenty minutes after the recording was made, I had edited the songs and uploaded them.  You’ve read that correctly, in less time than it takes to listen to the pieces, they were composed, recorded, processed, mastered, named and uploaded.

Today is also the 50th anniversary of the first Beatles song hitting #1 on the US pop charts: “I Wanna Hold Your Hand.” This whole project was inspired by this apparent coincidence in timing, and each track was directly inspired by listening to the sped-up Beatles original.  I hope you enjoy each of the 11 tracks I created!

While My Cacophonator Gently Weeps
Got To Get You Into My Cacophonator
All You Need Is Cacophony
With A Little Help From My Cacophonator
Sgt. Cacophonator’s Lonely Hearts Club Band
Cacophonator Came In Through The Bathroom Window
Lucy In The Cacophonator With Diamonds
Got To Get Cacophonator Into My Life
A Hard Day’s Cacophonation
You’ve Got To Hide Your Cacophonator Away
Cacophonator Wants to Hold Your Hand

It may be more convenient to listen to the entire album: “Cacophonator 2: Electric Boogaloo; A Love Tragedy in 11 Parts” on the RPM Challenge site’s Cacophonator page. Just scroll down to “My Player.”  There is plenty of February left: I encourage everyone to participate!

The Milwaukee Makerspace Theater

BIG_HMMMMMM2

Around 25 members have hopped in the new Milwaukee Makerspace Theater after the last two Tuesday meetings.  Its up and running in a “no hearing protection required” way!  The bass still goes way down to subsonic tones, but its being powered by a small & sensible surround sound amp.   Its a very immersive audio experience, and likely sounds much better than any 5.1 system you’ve heard because there’s only one seat!  The sound has been optimized for the single theater-goer: You!  The theater is hooked up to a DVD player, and is available 24/7  for any member to watch a movie in: no check-out required.   Note that any video source you have can be hooked up via the HDMI cable.  Alternately, you can follow the lead of JasonH, who used the theater with a portable audio player to rock out while he worked on his own project near by. See the photos below for the simple instructions on how you can start up the theater, and feel free to take a break from making by using the theater!

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Glass Etching

Bottles

I did a few glass etching classes last month, and the timing was good because people were looking for unique gifts they could make for the holidays, and a personalized etched drinking glass makes a fine gift!

We started out by cutting vinyl on the Silhouette Cameo and then sticking it onto glass bottles. This let everyone get a feel for the sandblaster before they moved on to a real glass.

After everyone used the sandblaster I helped people get their artwork ready, we cut the vinyl, and then everyone etched their glass or mug. (We also got a few lessons on troubleshooting the “temperamental” sandblaster.)

Unfortunately I was too darn busy running the class to take any photos (though Ben did) but I liked what Audrey did, so I pretty much copied her and made my own “Milwaukee Makerspace Racing Team” drinking glass. Here it is!

Glass Etching

Here’s a close-up of the etch. It looks pretty good! The process isn’t too hard, but there are a lot of little details to know along the way. I’m glad I could get people up to speed. (I guess my etching of 300+ items back in October helped!)

Glass Etching

If there’s still interest, I can run another class, but there’s only two people right now who missed it, and I’d like to get a few more people before committing to a full class. (Rumor has it we may also be seeing a sandblaster upgrade soon!)

How to Build a Kitchen Table in an Assortment of Easy Steps

The Finished Product (so you keep reading)

14 - Finished1

So I moved into a new place and need furniture (which you might tell from the background of some of these photos). But, I kept looking at big box store stuff and it was expensive and poorly made. So I figured I could build something myself for cheaper and it would last longer! Plus I get to build something, which is half the fun.

Step 1: Find Inspiration

Chadhaus Furniture ($6,400)

From Etsy

Step 2: Design Your Own

I drew out a bunch of hand sketches to figure out dimensions and proportions. I actually wandered through a couple furniture stores and checked their measurements for a 6 person table… I also measured the room its going in to make sure I had space to get around it.

Then I pulled out my middle school drafting skills and an engineer’s scale to see if everything would work and kind of went from there.

Step 3: Buy Material

01 - 200 bucks worth of Cherry

This was something like 45 board feet of 6/4 cherry that I had roughly planed. By this point in the project I didn’t really know if I wanted rough cut lumber or if I was going to plane/sand/joint the whole top together as one solid piece.

First part of the bill, $200 for all this wood.

Step 4: Rough Layout

02 - Rough cut to size

I bought most of this material before I actually had a scale drawing I liked and before I had final measurements that I was going to build to. So I rough cut these to 66/68 inches long as I knew I would end up losing a bit of length during glue up.

Step 5: Build the Legs

Substep 5.1: Miter the steel for the legs.

The legs were 1×3 inch steel tube. 24 inch for the width and 36 inch stock cut to 29 inches long. So that plus the ~1.5 inch table top would be right about 30 inches high. (which seems about standard)

03 - Miter table legs

You can also see one of the dimensional sketches I carried around for reference.

Something like $120 for all the steel.

Substep 5.2: Learn to Weld

(Something something, draw an owl.)

My uncle taught me how to weld a year or so ago to build a similar looking entry way table so I had some experience welding before this. Plus I can soldier, which is nearly the same thing.

04 - First pass at welding

This was my first attempt at welding the whole set of legs into a square structure.

05 - Second pass at welding

 

This was the second set of legs. This set went a lot smoother as I figured out the process a bit and got into a groove for welding.

I also welded on the little tabs which I drilled out for 1/4 inch lag bolts.

Substep 5.3: Grind.

06 - Lots of grinding and flap wheel

 

Lots of grinding. Also I ground my name into the underside of one leg to sign my piece. I also finished these with a clear matte finish so that they wouldn’t rust.

Step 6: Assemble the Table Top

At this point I decided that I wanted to edge joint everything together and I wanted the top smooth so I didn’t get little crap in the gaps. So I took it back to Kettle Moraine Hardwoods and had them plane the rough lumber down to 1 3/8 inch and straight edge both sides. Then I put everything together once more for a rough layout.

07 - Last rough layout before glue

Substep 6.1: Biscuits and Glue

A hearty breakfast?

Because the boards were still kind of rough as I didn’t plane them down enough to get all the warp out of them, I decided to use biscuits to help the glue up and keep the top aligned and flat so that once I had to finish it I didn’t loose any more thickness. Also I tried to match up colors a bit differently than when I had rough boards.

(Side note, remember to alternate grain on each board to help prevent cupping)

08 - Give em the CLAMPS

Substep 6.2 Sanding

09 - Blank after glue up

So here it is after glue up. To save myself a bunch of time I took it back to Kettle Moraine Hardwoods as they have a 42 inch drum sander you can use for a couple bucks in shop fees. Then I transported it to the Makerspace to use the panel saw to square up the ends and sand it again to finish. (40 grit drum sander, 80 grit -> 180 grit -> 320 grit on the palm sander)

10 - Rough sanding on belt sander then finished by hand

Step 7: Finish

I really like oil based finishes as they bring out lot of the natural color and figure of the wood. Plus I had some lying around from that entry way table I mentioned earlier so I knew how the finish would turn out. (Velvit Oil)

11 - Oil finish vs raw

You can see the difference in color (sorry for the poor color balance) but the cherry has a beautiful redness to it. I also applied Paste Wax to the top as extra insurance against stains and water, etc.

Step 8: Attach Legs

12 -  Attach the legs

I kind of eyeballed this. But I did use a square and my engineer’s scale to try to align everything as best as possible. I did pre-drill holes for the lag bolts as there would be no way the bolts go in without them.

Step 9: Celebrate!

13 - Celebrate with beer

With beer!

Also I stood on the table to make sure it was stable, and it was. So that worked out.

Alternate shots:

With perhaps more natural lighting.

14 - Finished1

And a close up of some of the figure in the cherry.

15 - Closeup of the figured cherry

Conclusion:

So for $350 in materials ($200 for wood with lots left over, $120 for metal, $30 for shop fees) I built a table I’m pretty satisfied with. Plus its way cooler than MDF crap with veneer or paint to cover up crappy wood. And should last quite a while… I hope.

Laser Cutter Venting System, Version 5.0

Sometimes solving one problem creates a few new ones! As part of the Laser Cutter Room Reconfiguration, the exhaust system got an upgrade. A new, bigger, more powerful fan meant we needed a new way to control it. The previous system (Version 4.0) was a simple on/off switch. That just wasn’t going to cut it for this industrial grade blower. Tom G., Tony W., myself and others spent the holidays installing this new two-horsepower beast above the ceiling in the Craft Lab. Once it was hung from the roof joists with care, Tom got to work ducting it over to the Laser Cutter Room. Finally, when all the heavy lifting had been done and the motor drive had been wired up, all we needed was an enclosure for the switch.

The request went out on the message board. Pete P., Shane T., and I all expressed interest, but life got in the way and it soon became a matter of whomever got to it first would be the one to make it. I ended up devoting the better part of last weekend to this project (much more time than I anticipated) but I can honestly say I’m pretty happy with the result.

LCEC01

The goal was fairly straight-forward: make an enclosure for the switch Tom had already provided. It was a color-coded, 4-button, mechanical switch that had been wired to provide four settings: OFF, LOW, MEDIUM, and HIGH. The more laser cutters in use, the more air you’d need and the higher the setting you should choose. There’s four duct connections available for the three laser cutters we currently have.

There’s a saying: “Better is the enemy of done.” Truer words have never been spoken in a makerspace.

At first I wanted to build the enclosure out of acrylic. Then I remembered this awesome plastic bending technique that Tony W. and some others told me about. I found a video on the Tested website and got inspired. (If you don’t know about Tested, please go check it out. You’ll thank me later.) Unfortunately, my bends kept breaking and melting through, so after a few hours of tinkering I moved on.

Thankfully, we have a small cache of plastic and metal project enclosures on our our Hack Rack. I managed to find a clear plastic, vandal-proof thermostat guard. It looked workable.

I tried laser cutting it, but the moment I saw the plastic yellow and smoke, I knew there was probably some nasty, toxic stuff in it, so I moved to the CNC router. About an hour later I had my holes cut.

Then came the wiring. Up until this point I had been focused on the control box itself. Now I wanted to add a light!

No, two lights! Yeah!

One light to tell you when everything was off, and another that lit whenever the fan was in use. People could look at the lights from outside the room and instantly know if the fan had been left on. (It should be noted that the new fan, despite being twice as powerful than our last, is actually much quieter. Tom added a homemade muffler to the inlet of the blower and shrouded the whole contraption in 3″ fiberglass batt insulation. The best way to know if the fan is running is to open a slide gate damper and hear air being sucked in.)

OK, I totally got this.

Draw myself a ladder diagram and get out the wire connectors… Remember that I need to isolate the signals from each other so any button doesn’t call for 100% fan… A few more relays… Some testing… and done!

Wait a second… the motor drive doesn’t have a ground for the control signal.

Hmm.

Guess I can’t power it from the drive. I’ll just tie into the drive’s ground. Nope, that didn’t work.

I’ll read the motor drive manual. OK, it has a set of “run status” contacts I can monitor.
….and they’re putting out a steady 0.4 volts DC. That’s enough to light up a single LED! …except, no. It’s not lighting. Doesn’t seem to be any real current.

I’ll just use a transistor! That’s the whole point of a transistor!
….well nothing I tried worked.

I’ll build a voltage multiplier circuit!
….and this isn’t working either.

On Day 3 of this “little project” Ron B. made a comment about using a pressure switch of some kind.

Wait.

We have a Hack Rack full of junk and I know there’s this old bunch of gas furnace parts. It couldn’t be that easy…

LCEC02

Yeah. So, three days (and a few frustrating epiphanies) later, this all came together. Press the beige button, get some air. Press the other buttons, get some more air. Any time there’s suction, the red light comes on. The indicator light is powered by its own 24 volt DC wall pack. The pressure switch has both normally open (N.O.) and normally closed (N.C.) contacts so it would be totally feasible to add another light at some point. The controller could display “OFF” or “SAFE” or whatever as well as “ON” or “FAN IN USE” or whatever. The text is just a red piece of paper with words printed on it, then holes laser-cut out to fit. We can trade it out with different words or graphics if we ever feel the need. I was just glad to have it done, so I called it. Better is the enemy of done, indeed.

LCEC03

You can learn more about the evolution of our laser cutter venting system on our wiki!