Friday Night Drawbot

Arduino-Powered Drawbot

Friday night turned into Robotics/Art night at the 2XL Makerspace. I remembered seeing this Drawbot Project, and while you can modify normal servos to be continuous rotation servos, I already had some continuous rotation servos on-hand, so we got to work. (Or play, if you prefer.)

Drawbot parts
Drawbot parts

The Drawbot consists of just a handful of parts. Here’s a list of the items we used:

All of these pieces are available from our friends at Adafruit Industries. You can probably find the parts elsewhere as well, and you don’t need a Boarduino specifically, as any Arduino board will work. I just used the Boarduino because it’s small.

Sharpies and Corrugated Cardboard
A Pack of Sharpie Markers

Oh, you’ll also need some Sharpie markers (I recommend a nice 8-pack of various colors) and a 9 volt battery, a platform, and something to hold it all together.

Servos taped together
Servo motors held together with some tape

The building of the Drawbot was pretty simple. I started by using a bit of tape to stick the servos together with the wheels facing out. This gave me the width of the “platform” I would need. (It had to fit between the wheels.) I used corrugated plastic because it was handy. It’s very lightweight, easy to cut, and pretty strong. You could certainly use cardboard or something like a plastic CD case, but I’m telling you now… corrugated plastic is awesome. (I’m already using it in my next project!)

Once I had the servos secured to the platform with some rubber bands, I put the battery and the breadboard on top of the platform. The placement may be a little tricky, as you need to determine the correct balance. I wanted it to be a bit heavier on the side that would hold the marker, but didn’t want too much weight on that side. Rubber bands make it really easy to move things around.

Close-up of Drawbot
Close-up of Drawbot

With most of the pieces in place, I added the jumper wires between the servos and the breadboard. That’s it for the wiring.

At this point I wanted to test it out. I was impatient and just wanted to find some continuous rotation servo code. A quick search led me to the post Controlling a Parallax (Futaba) Continuous Rotation Servo with Arduino. I ended up simplifying my code even more. Right now the Drawbot just goes in a circle. Yeah, it’s simple, but that’s the way I like to start things. Get the simplest thing working first, and then go from there. (Code is at the bottom of the post.)

Marker holders
Marker holders made out of corrugated plastic

So we now had a robot that went in circles. At this point we figured it was time to draw something! Back to the corrugated plastic. This is another place where the plastic shines. I cut a small piece, and then cut a hole with an X-Acto knife where the marker was going to go. I cut the hole a bit small, and when i slide the marker it, it held it nice and tight. I’m glad I didn’t use cardboard, as it just doesn’t have the strength of the plastic.

Drawbot on it's first run
Drawbot on it’s first run

With the marker in, it was time to test it. We put it down in the center of a 24″ x 18″ drawing pad and turned it on. It spun around drawing circles. Success! We managed to build a robot that can create artwork. :)

Artwork by Drawbot

Since things were all loosey goosey, meaning, our marker holder could shift around, the pad was on an uneven floor, the servos were probably not perfectly matched, etc. We got a circle, and another circle, and another one, all overlapping. In a perfect world I’d suppose you’d just get a circle with every other circle drawn directly on top of it. I think it turned out better our way.

Drawbot making overlapping circles
Drawbot making overlapping circles

We figured that two markers would be better than one, so we tried that next. The results were pretty good. Here you can see how the circles start to overlap. We’re hoping to try with some bigger paper to see what happens when it doesn’t run out of room.

Here’s our code…

 * Drawbot.pde

int servoPinL = 9;
int servoPinR = 10;

void setup() {

void loop() {

Again, this code is really simple. All you’ll get is a circle, or, a bunch of circles. But now that we’ve got the Drawbot working, we can start playing around with modifying the code to change it up a bit. We look forward to more robot-created artwork in the future!

Note: Check the project page for more info.


DIY iPad Stylus

So this is how I typically do things… I get an idea, like, for instance, I say “Hmmm, I know a few companies sell a stylus for the iPad, for those times you don’t want to use your finger, I should check that out” and I did, and then I came across this Make video called Collin’s Lab: DIY iPad Stylus and think, “Hmmm, I have a pen, conductive foam, and some wire… I’ll make my own!” So I did…

DIY iPad Stylus

Here’s the result. I used a Pilot G2 pen (as they are my favorite) and I ended up using the Dremel to widen the tip of the pen a bit so the conductive foam could fit through the hole, and I also used the drill press to put two small holes in the barrel of the pen for the wire to go through. (I wanted to avoid using tape as Collin did.) I actually drilled right through the rubber grip and into the pen. The end of the wire then got pushed through the rubber grip, through the pen barrel, and got pulled tight inside the pen. You can see some of the excess wire near the middle of the pen. You can also see an extra hole near the tip, as I drilled all the way through with the drill press. I won’t call that a mistake, as I was still figuring out how I was going to make it all work at that point. I tend to do that… plan as I go.

Here’s a close-up of the tip, where you can see the hole that the wire feeds out of. You can see the tip created with the conductive foam. I’m not 100% happy with the tip. I don’t know if there are different hardnesses of conductive foam, but this seems too soft. I also probably could have used a bigger piece of foam, but it ripped while inserting it, so I just left it as is was.

So… does it work? Yes!

DIY iPad Stylus

Here’s a really bad drawing I made using the stylus and Doodle Buddy on the iPad. The whole process of making this probably took 20 minutes, and I did already have all the tools and materials on-hand.

P.S. I like making things.


A Very Maker Christmas

A Very Maker Christmas

We’ve been busy in the days leading up to Christmas, and the elves (kids) spent a lot of time in the “2XL Makerspace” and with my help we hand-crafted a number of ornaments. In the true tradition of making gifts rather than buying them, we had a blast…

I made good use of the tools that belonged to my Dad, and a box of scrap wood my brother gave me (along with my own scrap wood, which I’ve probably moved with me for the last 5 years/4 houses.)

I can see this becoming a tradition… spending time with the kids making things in the weeks leading up to the Holidays…

File Under: Awesome.



Dremel Moto Jig Saw

Thor Drill Press Model #580

I’ve been playing with some new lighting techniques (learned at Z2 Photo) and figure I’d give it a try while creating an inventory of some of the tools in the “2XL Makerspace” (also known as “my basement workshop.”)

These tools belonged to my dad, and they still work quite well. I find it interesting that many of the tools we use today (computers, phones, and even software) will not be used by our children when they are our age. By that I mean, the actual tools we use. If you’ve got a PowerBook now, you’ll probably replace it in a few years, and then replace that, and replace that, and on and on… in comparison, the jig saw and the drill press were the exact same ones my dad used over 25 years ago to make things.

Maybe the cycle is just sped up… I just gave my kids the old 20″ iMac because I replaced it with a MacPro. Of course in a few years that iMac will seem slow and outdated, or it will break, or die, or somehow become useless. The lifecycle of our tools for digital work seems so short… My youngest daughter asked if she can have my DSLR when I get a new one. Is it normal for her to think I will get a newer (better, faster) camera at some point? I’m sure I will… but I’m also sure that in 10 years she’ll be able to buy a newer (better, faster) camera for half of what I paid for mine.

Is this the price of progress, or is it just the difference between tools that create things in the physical world vs. tools that create things in the digital world?



What have I been up to?

Well, I built a panoramic head for my camera…

Panoramic Head

…then I took some pictures with it, stitched them together, and made this panorama…

Lake Street

…then I put it into a Flash player so you could spin around in it!

I’ve also been using a Nodal Ninja (a really nice panoramic head which I highly recommend if you’ve got the cash) and digging into panoramas and panoramic photography, and stitching and viewing software…

I used to do a lot of QuickTime experiments (3D objects, etc.) about 14 years ago, so I have a certain fondness for this sort of thing…

If PhotoCampMilwaukee2 happens, I’d love to share what I know about this stuff.

Update: See the project page for more photos and info.