We made a giant laser cut & etched banana and stained it yellow and put it on the wall. Why? I’ll tell you why. Because we’re artists and we have a sense of humor and sometimes enjoy social commentary. But wait, there’s more!
You see, this specific banana is best know as being a piece of art created by Andy Warhol. Or maybe it’s best known as being the cover of a Velvet Underground album. Also, as we all know, Warhol was a thief. But maybe he was a thief in the way Steve Jobs was a thief. “Good Artists Copy; Great Artists Steal.”
So I stole Warhol’s banana, but I really just downloaded a file that someone else created, which is fitting. Stealing is pretty easy nowadays. Thanks, Internet!
Maybe you want to buy your own banana? You could probably do that, but you can’t buy our banana, because it’s not for sale! (I remain hopeful that someday someone comes into the office and actually recognizes the banana.)
The banana was laser etched and then cut from 1/4″ Baltic Birch Plywood and it took about five hours. I think it should have gone faster but this was (more or less) a stress test for the laser cutter. It definitely etches (and cuts) stronger on the left side than the right. Good to know.
Becky is holding a Cutie (aka a “mandarin orange”) for scale. I forgot to bring a banana for scale. I should probably do that. There’s also a 12 ounce can in some of the photos, which is also for scale. I don’t know how many ounces the banana is.
For this year’s WMSE Art & Music event, I created a new board I call OctoNoise. It’s an eight note piano featuring capacitive touch pads, LEDs, a Teensy LC microcontroller, and some fine woodworking. This is somewhat similar to last year’s piece.
You may know me for my work with decagons, but I also work with octagons, and this pattern is known as a 16 cell and it worked well for my design which utilizes 8 touch pads and 8 LEDs.
I’m not an amazing woodworker, but after laser cutting wood I can typically sand it, stain it, and add some polyurethane. At least it looks (somewhat) nice. I didn’t alter the bottom piece, and I just left it as a square, the way I received it from WMSE. My original design for this piece (over a year ago) was a bit different, but I wanted this to match the style of last year’s WMSE piece (and I was a bit rushed getting this done.)
The OctoNoise features and on/off switch, which is handy because it runs on batteries. I can’t tell you how many times I’ve made electronic things for myself and not included and on/off switch. It’s nice to have one! When you turn it on the touch pads calibrate for about 5 seconds. There’s a startup sound that happens during calibration. (I added a note about that on the back of the piece.)
There’s a “somewhat” hidden control knob on the side that ajusts the delay between notes. The way the code is written, it plays one note at a time, but you can alter that to very quickly (or slowly) oscillate between multiple notes. You can get some interesting variances in sound by turning the knob.
Note that it is difficult to turn the knob while also touching the pads to make sound. This is by design, as it’s also difficult (if not damn near impossible without using various parts of your body) to play all the notes at once. This was done to encourage collaboration and playfulness.
Here’s a side view. The height was determined by the speaker that was chosen. Once again we’ve put the electronics on display as part of the piece rather than hide them inside an enclosure. They are mean to be celebrated! (Each wire has a label showing what it connects to, if needed.)
Here’s the Teensy LC, which runs the code. The board has built it capacitive touch pins, which make writing the code fairly easy. The notes used are C5, D5, E5, F5, G5, A5, B5, C6. This is real piano, and you can play actual songs. I based the code on a project I did for Brown Dog Gadgets a while back. You can check out their Touch Piano on Github.
This device also contains an built-in amp with a volume control. Again, a sometimes rare feature in the things I build. Often amps require 12 volts and that’s not always fun to deal with, but I’ve found some that work on variable voltages from 3 to 12 volts, so running them at the same voltage as a microcontroller becomes very easy.
Besides all the wood and electronics, there are some 3D printed parts that pull it all together. The on/off switch, delay control, amp, and battery holder all have their own 3D printed part that they attach to and then easily attach to the wood with some #4 screws. Once again, things are left “open” to celebrate rather than hide the electronics.
The other 3D printed pieces are the custom standoffs that raise the top piece above the bottom piece to (partially) enclose the electronics. I created a 2D profile from the original artwork used to laser etch & cut the piece to create the correct angle. I then extruded that design to make the tall standoffs and printed 8 of them.
I started playing around with the #plottertwitter thing and wanted to do some creative coding with Processing, and at least one person asked about the code, so I’ve included it below.
Instead of drawing a rectangle, I’m creating a shape, and then varying the position of it a bit more with each row that is drawn. I reused some code I’ve used plenty of times before that keeps track of where things are drawn so the code knows when to start a new row, and when the screen is filled. After it draws a screen full it will save a PDF and exit.
Once you have a PDF (which is a vector file) you can make your plotter (or laser cutter, or CNC machine) do what you want with it. I typically bring the PDF into Inkscape and make any adjustments needed before I save it out in a format suitable for the machine I’ll be sending it to.
I should mention that the idea for this started maybe three years ago. I think it was during a meeting for Maker Faire at Milwaukee Makerspace and I tossed out the idea of building a giant light sculpture using light bulbs. Lance and Chris talked about it a bit and Tom started looking up parts on Alibaba. Nothing came of it that year, and I sort of forgot about it for a while. In fact, I really didn’t think about it again until after we completed the DecaLight last year. Once the two dimensional relay controlled light bulb thing was done I thought going three dimensional would be a good idea.
I modeled the cube in OpenSCAD, and then animated it just for fun. I figured out how many pieces of each PVC joint I would need, and while I originally thought a 20′ cube would be a good idea, after some initial tests (and the unavailability of 10′ PVC pipe) I ended up going with a 10′ cube so the 5′ PVC pipe I could get would work.
Here’s the first sketch of the Giant LED Cube. By now I had decided that I would use LED light bulbs and standard household lamp sockets. The nice thing about using such common parts is that they are very cheap. I found these Black Bakelite Fixture Socket with Terminals and ordered some so I could test the fit. It was close enough that it would work, and I just needed to make a small adapter. Well, at least 27 small adapters.
I designed and 3D printed over 30 of these using clear ABS, which is remarkably close to being white, and since you wouldn’t really see them, I was fine with the close match. I cranked these out so I’d be ready when they were needed. Like many parts of this project, they are just press fit into place. The entire thing was designed to be easily assembled and disassembled for making transport and storage an simple affair.
I had the basic design of the cube figured out, so I decided to work on the controller. Since we’d have 27 LED light bulbs I decided to use an Arduino Mega, which had plenty of I/O pins, along with two 16 channel relay boards. LED light bulbs are pretty lower power (compared to incandescent bulbs, anyway) so even though they’re 110 volts AC, 27 bulbs all on at the same time probably pulled less than 6 amps.
The image above represents my first attempt at layout out the controller, which I eventually abandoned. The screw terminals ended up not being a good idea. I would be pretty busy running Maker Faire so I assumed that I could find helpers able to strip wire, put them into the screw terminals, and get it all right. After attempting this myself on a small scale I decided that it needed to be even simpler, and clear enough that almost anyone could do the setup. So I scrapped the screw terminals. Around this time I also decided that running all of the power cords inside the PVC was going to be tedious and difficult, so with the decision to just run the cords on the outside (at least for this installation) I decided to just use standard household plugs. This would allow nearly anyone to just match up some numbers and plug things in. Simple wins!
The design process for the Giant LED Cube wasn’t too difficult. Doing this like this (designing, specifying parts, building, etc.) is pretty much my day job. The wiring was definitely tedious, and required at least one unexpected hour-long troubleshooting session due to a bad connection. I had a lot of help with the wiring of the lights from Adrian, and a lot of help with initial assembly from Becky. Without their help things would have taken me a lot longer. (Thank You!)
I think I’ve spewed enough about this project for one post (which I wanted to get out last month!) so I’ll end it here and get working on Part II ASAP.
I came across this DIY Printmaking Press from the Open Press Project and since I’ve always been a fan of printmaking I thought I should 3D print a printing press on my 3D printer so I could print paper on a 3D printed printing press.
The (3D) printing went well, and all the pieces turned out good. I did add support to the rollers, to ensure they’d print well without sags. The one piece that is weird is the roller pin, which seems too small. It falls out a lot and doesn’t fit tight in the roller or the roller wrench. I may design a new one that fits snug.
I also did not have any 5mm bolts of the right length, so I used 6-32″ bolts. I’ll have to glue in the nuts so they don’t fall out, but that’s pretty minor. I’d also consider using hex head bolts and 3D printing little knobs to put on the heads so you can adjust the pressure without needing a screwdriver.
I did not have any press blankets, so I used some foam rubber sheets I had on hand. It seems to work okay. I may ask my printmaking friends for some scrap blankets.
For my first printing plate I grabbed a vector image of Makey and laser etched it using 3mm Baltic Birch. (Sidenote: LightBurn is awesome.) I did not seal the wood as I was anxious to make some prints!
This is a small press, and my plate was 57.5mm x 65mm. This might be a good press for making business cards or maybe printing stickers. The nice thing is that since it is so small, it’s portable, and you can make a lot of tiny prints for pretty cheap.
This was a fun little project and I’m guessing the cost of making this printing press was maybe a few dollars worth of filament and hardware. The press blanket is probably the more difficult thing to get cheap, though perhaps an alternative like some thick felt (or layered up thin felt) could be used.