In order to test the vibration reduction of the desktop being attached to the legs, I designed a new drop-in system of anchoring. This eliminated any additional load from the legs.
This worked really well. But the trade off was the fun experience of having the desk physically move away from you when the top was connected to the legs. For the presentation, this was the final design (albeit with the solid, one-piece top).
For the second prototype I wanted to revisit the two-part structure of the desktop. I had initially been worried about the weight, but realized quickly that with the CNC machine I could easily remove as much material from the wood as I wanted while maintaining structural integrity.
I used almost the same exact design as the first prototype with the only major adjustment being the removal of the interior leaf.
The motor was mounted to the underside of the desk and the top was clamped to the speed rail.
One solid piece reduced the noise dramatically. It also produced an unexpected, but not wholly unwelcome, side effect–because the desktop and legs were clamped together, the entire table vibrated and skittered around.
I still wanted to know how much the legs being attached actually affected the desktop vibration, so I thought up a less permanent way of attaching the top to the legs.
Things were coming together. The physical component of the desk was prototyped. I had network access. Now I needed to bridge the two.
In order to get enough power to run, Bertha, the vibration motor, needs 24v. The Arduino runs 5v. In this case, the Arduino acts as a gate keeper–when it gets a specific input (an SMS) it sends a little current to a transistor circuit which is the gate. The transistor does the job of electrically connecting the motor and its 24v power supply.
This little circuit board was designed to fit right onto the GSM shield. This would help keep the various network-related components in a relatively contained package–something that would be easier to mount to the desk.
Access to a network is basically what puts the “connected” in “connected-devices.”
For the Bad Vibes Desk, I wanted to be able to access the phone network in order to receive text messages or SMS. The Arduino Uno doesn’t have any type of connectivity, besides serial, on its own. In order to access the phone network I needed a GSM shield. That white square is a Quectel M10 radio modem, which connects to the network through GRSM (General Packet Radio Service), a data service on 2G and 3G mobile networks.
(Benedetta also happens to be a phone network wiz and she was kind enough to let me borrow a GSM shield that she had personally designed and had manufactured. That’s the smaller white shield below.)
A SIM card is also required in order to connect to the network. So for around $25 I got an AT&T SIM and a month of unlimited SMS.
I had a lot of issues during the first couple weeks of trials with both shields. Neither worked with the Arduino GSM library. So I bypassed the Arduino completely. Using serial communication and the native language of the GSM card, AT commands, I was able to connect to the network (on both devices) with a high rate of success.
Thinking I was in the clear, I left the GSM stuff behind for a few days and when I returned, nothing was working. So I brought it in to ITP from my apartment, where I had been doing the initial tests. To my chagrin (though not my surprise) it connected without any issues. In the end it seems like I spent two-plus weeks stressing out over nothing but poor signal strength in my apartment.
Once the GSM shield was connected, this was no problem at all. I used a slightly modified version of the Arduino GSM library’s ‘Receive SMS’ example code for my purposes.
Next was developing the circuit to trigger the vibration motor once a SMS had been received.
This week’s assignment was to create something that was a combination of two different materials that weren’t plywood or acrylic.
My idea was to juxtapose cork’s natural texture with a layer of metal. Working with cork was also a great excuse to learn a bit about the lathe, which I’ve been eyeing all semester.
One of the issues I ran into was finding good cork. There were some resources on the Fabrication class page, but they were expensive and didn’t have blocks thick enough to work on the lathe.
I improvised and ordered cork yoga blocks. At 6″ x 4″ x 9″, they were a perfect size.
For the metal, I walked around home depot until something caught my eye. I grabbed a copper pipe end cap and a brushed stainless steel-looking cup from the bath department.
I might have to write a separate post to profess my love for the lathe. Suffice it to say, working on the lathe was a lot of fun. It’s easy to get into a flow state and you’re also getting instant feedback on your progress. Plus the object organically takes shape, rather quickly, before your eyes. It feels very different from other methods of fabrication.
I’ll be adding a metal element to the bowl for consistency. I’m thinking a flat circle for a lid/trivet.
And next time I’ll be adding in stripes of multi-colored thread for another new texture.
For this project I focused on designing and building the desktop and always intended to use pre-fabricated (or nearly pre-fabricated) legs.
For this first prototype design I imagined a frame of sorts with a lip that was attached to legs, and a middle panel that drops into the desk, resting on the lip. The motor would be mounted to (and only transferring energy to) the lightest part of the table–the panel.
When designing the desk the most important factor from an engineering standpoint was the weight of the table: The lighter the table; the more energy would be transferred from the motor; the more intense the vibration. Which is the point.
I used Illustrator to design/create the files and the CNC machine to cut the two sections of the desktop. It worked like a charm. Although because of the diameter of the router bit I needed to do a significant amount of sanding around the corners to create a seamless fit.
I drilled the motor mount into the untouched section on the underside of the panel, which was designed as a mounting block.
I clamped the desktop to legs I made of aluminum speed rail. This worked, but ended up being incredibly loud. The panel and frame knocked against each other around a hundred times a minute. This sounded like a mini jackhammer. It was unpleasant and annoyed everyone in the shop. Not ideal.
A second prototype was imminent.
It’s been a bit since introducing the Bide Vibes Desk project. And since it’s due tomorrow I figure it’s time to go over what’s happened since our last episode…
This is Bertha. She’s 45mm in diameter. Weighs in at a staggering .2 lbs. And is rated to operate at 24V. That’s (and I’m guessing here) about 100 times larger and more powerful than your iPhone’s puny vibration motor.
Here’s the spec sheet for you motorheads: Bertha’s Spec Sheet
You might notice, as I did, that there’s no engineered-in way to mount Bertha. Which proved to be a pain in the ass.
I considered buying some sort of pipe fitting or bracket, but that would have been expensive. I also would have had to customize it to some degree. So I decided to prototype a mount with what was lying around in the meantime, while I researched a longer-term solution.
To the junk pile!
I found a 2 x4, cut it down to size, drilled a hole, and cut in half. Using a couple of wood screws I created a surprisingly decent clamp to hold the motor in place. I soldered on the wires you see dangling out. In these photos they’re temporarily connected to a bench power supply that I was using to test Bertha’s vibrational strength.
If ITP had an (even more) unofficial slogan than “a Center for the Recently Possible,” it would be: “Everything’s a Prototype.”
This is still something I’m coming to terms with on a daily basis. Obviously there’s only so much you can do inside or outside of a class, within a semester, while you’re taking a handful of the most mentally grueling, thought and production intensive classes imaginable. But, still. In my head I’m always looking at a polished, finished, fully realized piece of work on display in some imagined gallery-type space. White walls. People quietly milling about. Curious but also very respectful of whatever project of mine they’re enraptured by. They give it plenty of space, but you can see in their eyes the need to play with it. So while no one’s looking, they do. And it holds up. Rock solid. No janky screws. Perfectly squared. If it’s a digital piece, maybe they somehow pull up the code. And it’s beautiful and concise and well organized.
But this isn’t the real world. Or, in any case, it’s not whatever ITP is. So I’m stuck doing the best I can. Improvising. Making it up as I go.
Everything’s a prototype.
It’s only been a week since we used the laser cutter. A week since I fell in like with it. I’ll admit, I’ve been daydreaming about accurate cuts, the precision, the perfectly straight lines, laser-light evenings alone in the shop. But like a fool, I was blinded by love. And got burnt. Metaphorically, at least.
I had picked up some wood off the street. The top of a wine box. I was going to laser cut some pieces for this week’s enclosure. But when I went to cut it, things went south pretty quickly. I had put masking tape on the face being cut (per that Instructables post) to prevent any smoke from marring the surface. Instead of working, the laser set the tape on fire. Then the wood. It just wasn’t going to happen. Everything’s a prototype.
Luckily someone had tossed a few really nice pieces of scrap wood. Long, slender. Cherry, maybe? They’re a bit reddish. I made some quick measurements and banged out a little box. Not perfectly squared. Everything’s a prototype.
Next I went to the junk shelf to see what I could see. I took apart a DVD player and a fog machine for parts. From the DVD player I got an LCD screen and from the fog machine I got some cool switches. A concept was forming. Maybe some sort of automatic counting device or a mysterious smart box that knows the secrets of the universe (or your fridge or something).
I, rightly or wrongly, went back to the laser cutter to cut out spaces in the lid for these components. I screwed up here. I was in a rush. I didn’t measure properly. I didn’t calibrate the machine like I should have. But I got away with a couple nice cuts that were close to what I needed. Not perfect. (You might be expecting my new mantra to show up right here, but it doesn’t. Error on my part doesn’t fall into the Everything’s a Prototype category. I should have more patience. I know. I’m working on it.)
The components don’t connect to anything. Maybe the switch could, but the LCD would be tough. I’m not sure about any of the connections and I imagine it’d be painful to look up. If it’s even possible.
And so, it remains a conceptual object. Full of possibilities. It’s function: whatever amazing, wonderful, impossible thing you project on to it. Your own imagined prototype.