Category: Uncategorized

Stipple the Hoan

StippleGen2 from our friends at Evil Mad Scientist Laboratories is a great little application for creating line art from graphic images. The docs on their wiki will give you a good overview of what it does.

When I first got my Egg-Bot I used an application called “Voronoi Stippler” to play around with stippling, but sadly the code for the application was taken offline. StippleGen2 takes the place of Voronoi Stippler quite well!

Original Hoan Bridge Graphic

I started out with this graphic of the Hoan Bridge, a Milwaukee Landmark, and converted the small color image to a larger grayscale image. (Why the Hoan Bridge? Because someone on Facebook suggested it!)

Hoan TSP
TSP Artwork

Here is the result of generating the TSP art. What is TSP you ask? Basically, it’s a path with a single line. It’s great for generating toolpaths used by things like CNC machines, engravers, routers, lasers, etc. (Find out more about TSP!)

Hoan Stipples
Stipple Artwork

I wasn’t convinced the TSP art would come out great, so I went to the circular stipples. Here’s the final version, which is incredibly hard to see rendered properly at this size, so look below for some zoomed in versions.

Hoan Stipples Zoomed
Stipple Artwork Zoomed In

Hoan Stipples Zoomed More
Stipple Artwork Zoomed In More

Hoan Stipples Zoomed Even More
Stipple Artwork Zoomed In Even More!

As you can see, the circles overlap, which means if we were to etch this with a laser, and use the vector setting (as opposed to raster) it would see each circle as a distinct object, and etch each one. (Etching as raster would most likely just etch it all as one single blob, no individual circles.)

So because each circle will be etched individually, and they overlap, we’ll end up with different heights/layers, as it were, due to some areas of our material being hit with the laser more than once. In other words… texture!

Final Laser-etched piece

Here’s our final piece of laser-etched Baltic Birch plywood. Below you can see some zoomed in shots showing the surface. Notice how the circles are so small they essentially looks like dots. (You can click each photo to see the large version on Flickr.)

Close-up of stipples

Texture in upper-right corner

Texture in the letter “N”

Tags lasercutter, stipple, stipplegen, wood

Uncategorized

3rD Times The Charm!

Three Motor Holders

While I usually describe 3D printing to people with something like “you can make beautiful things that are art, or functional things like parts” I’ve been printing a lot of parts lately (thought I still print pretty things!)

The parts I’m printing are of my design, for things I am building, and they often have to fit existing real-world objects. The process usually involves measure thing with calipers to get dimensions, and then designing things in 3D software. (I’m leaning more towards OpenSCAD latley, as opposed to Sketchup.)

If you’re just downloading and printing objects from Thingverse, they’ll (hopefully) work on the first try, but if you’re doing everything on your own, it may take a few tries.

I wanted to print a small motor mount for this DC motor that Adafruit sells. So I got out the calipers and went to work.

Motor in the second holder

For the first attempt (see top photo) I completely screwed up by using the inside dimensions (where the motor should fit) as the outside dimensions. Stupid mistake! On my second attempt I got it right, and the motor fit almost perfectly.

Motor in third holder

On the third iteration I made minor adjustments to the outer walls, and I also added an “air hole” on the top. The motor has two slots in the body which I assume draw air into it to prevent overheating. (You can see I know very little about motor design right now.)

Motor and holder

Back in June when the guys from MakerBot stopped by Milwaukee Makerspace, I talked to Skimbal, and asked how many revisions he went through when designing things, and he said about two or three. I was impressed by this because last year I tried designing a real-word replacement part and I think I made about ten versions of it. Of course part of this was my lack of 3D skills, and part of it may have been issues with the old CupCake I was using.

Motor in the holder

So I’m pretty happy with the fact that I can get a good version of a part in just a few tries now. (Though I should admit that I’m not happy with the slots for the screws, and may end up tweaking things a bit more, which is pretty darn easy in OpenSCAD.)

When I was talking to someone about 3D printers this summer, they didn’t see the point of having one at home when there were so many companies that allowed you to upload a design and would print it and ship it to you. Here’s where a home 3D printer shines; I can measure a part, get a prototype printed, test it, and print another version all in a single afternoon. Now that’s rapid prototyping!

And a mirror holder!

Oh yeah, I also printed a mirror holder. It took just two revisions to get one that worked well.

Tags 3dprinting, design, prototyping

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Poundin’ Sand – Complete!

Post author By Pete Prodoehl
Post date 2012-09-04

Poundin' Sand

In my last post about my Nerdy Derby car, all you saw was a bunch of laser cut wood pieces… well, here’s the final car.

It’s almost dimensionally the same as a standard Pinewood Derby car. The body is constructed out of panels that were laser cut rather than a block of wood. Because it’s hollow inside, I filled it with sand. Why not lead? Well, someone else is already doing a car out of lead. I also though about marbles or something else that would roll around inside. I also thought about making one with acrylic and filling it with water.

The bottom has two pieces of wood attached so I’d have something to pound the nail into to attach the wheels. I glued the two piece together and then drilled a hole between them. (The wood is just 3mm thick, so layering made sense.)

I spaced the wheels the same for the front and back, so there really is no front or back… it’s the same either way. You’ll also notice I did a terrible job of placing the lettering. I just added it to the side panels without thinking about how the wheels would get in the way.

The wheels are also 3mm wood, and I’ve sandwiched three of them together to make each wheel 9mm wide. I was going to glue the layers together but I figured I’d just put them on and allow them to spin independently (if possible.)

If this car wins nothing besides the “laser cut wood filled with sand” category, I’m fine with that. I learned quite a bit in the process of building this, and if I build another car, I have some experience to build on. (I also managed to cut a big pile of wheels and have nails to fit them, so we can have supplies for people to make cars on the spot.)

Update: Files are now on Thingiverse.

Tags cars, lasercutter, makerspace, nerdyderby, sand, wood

Uncategorized

Nerdy Derby – Poundin’ Sand

Post author By Pete Prodoehl
Post date 2012-08-29

If you saw my last post about the Nerdy Derby we are planning, you probably figured at some point you’d see a car. Well, here’s my progress so far.

I cut the pieces from 3mm Baltic Birch plywood using the 60 watt laser cutter at Milwaukee Makerspace. Even the wheels are laser cut. I have no idea how well it will work, but I’m all for experimentation.

I’ve heard at least one person claim they will be building a car body completely out of lead, but I figured I already have plenty of sand around my house, so I plan to fill my car with sand, hence the name “Poundin’ Sand” (some of the runners-up included “Carl Sandburg”, “Sandoval”, “Sandy Bottom”, and “Adam Sandler”, but since “pound sand” sometimes means to engage in a futile activity, I thought it was fitting.

Besides, I’ve already awarded all the style points to Frankie for his belly tanker even though he’s not done yet, come on, just look at it!

Besides the glue to hold it together, the nails to hold the wheels on, and the sand, the rest of my car is 100% laser cut wood. I’m also planning another car that is (nearly) 100% 3D printed plastic. I’ve got some work to do on that yet, though the wheels should be done this week.

(Update: See the completed car.)

Tags cars, lasercutter, makerspace, nerdyderby, wood

Uncategorized

Nerdy Derby

Coming across the Internet via our old pal Matt Richardson is this thing called The Nerdy Derby which is, well, here’s how they describe it:

The Nerdy Derby is a no-rules miniature car building and racing competition inspired by the Cub Scouts’ Pinewood Derby. With a larger, more undulating track and no restrictions on the size of the cars or materials participants can use, the Nerdy Derby rewards creativity, cleverness and ingenuity.

So I thought this was a cool idea, and I think I’ve been able to convince some of the other Milwaukee Makerspace members that’s it a good idea, and we’re planning out first race.

We’re still nailing down the specifics on the track. We may use a standard issue track at first, or meld it with our own modified parts, TBD. Anyway, I’m hoping we can have at least one race on our own, and then we hope to bring it to BarCampMilwaukee7 on October 6th and 7th, 2012.

Car Kit

So start building your cars! And yeah, (almost) anything goes. (As long as it doesn’t damage the track.) Electronics? Cheese? Magnets? Whatever you can come up with.

It’s been quite a while since I’ve built a Pinewood Derby Car, so I thought I should brush up a bit. I ordered a standard kit, just to see it and get the physical dimensions. (And you can get a kit for less than $5.00 or if you want 10, they’ll come out to less than $4.00 per kit.)

But you don’t need a kit… all you need is something that will roll down the track. You got a box of LEGOs? Or something roundish? Go for it.

Axels and Wheels

I ended up getting a bunch of nails that are close enough to the right size, and I plan to try two things: laser cut a bunch of wheels, and 3D print a bunch of wheels. If I can make enough wheels, I’ll supply them to whoever needs them. As for the body of the car, we should have enough scrap wood at the Makerspace to provide plenty of cars.

You want in? Good. We’d love to have you in our race… Details to follow!

Tags cars, derby, nerdy, nerdyderby, race