News of the spooling machine

Posted on December 20, 2017

Ever since I presented my kinetic cabinet prototype for the IMCA 400 course, I have been spending time working on the pickup spooling machine. I originally sketched a rough idea, and as you can see from the sketch above, I refined the idea quite a bit.

I designed the body of the machine. That took me a while, in order to plan all the facets of the L-shaped body. I went again to ÉchoFab to cut plywood with the lasercutter.

The results seen above is quite satisfactory. However, at the time of cutting the body I hadn’t received the motors I ordered, and I discovered there wasn’t enough vertical space for it.

As I made a mistake with the 1/4″ plywood for the middle plate, I had to cut the shape out of two 1/8″ pieces that I had planned to glue together. I cut a hole in one, allowing to lower the motor a bit, and from then it fit properly.

As I was fiddling with the body and thinking how to add the pegs to hold the spool and the handle, I realized I had to cut some holes for those pegs. I updated the design and went again to lasercut some pieces. This time, I also redid the middle plate and the top plate: the middle plate integrates the hole where the motor sits, and the top plate has additional exhaust holes for dissipating the potential heat of the motor.

Tom from Concordia’s woodshop helped me design the bar that would hold between the pegs. Similar to the bar that holds toilet paper, this bar contains a spring to allow to put and remove it, to swap the spool when needed.

If you take a look at the bottom of the pegs, you can see an additional piece of wood, this is so that the top of pegs does not get pushed out by the spring pressure.

Spooling bit

I had designed a spooling bit to use with a drill, but it turned out to be a bit big and heavy. Also, when I tried using a drill, it wasn’t a success.

So I designed a similar bit, this time meant to sit on top of the motor. The one shown above is some 5 cm × 5 cm × 4 cm, also much lighter. There are holes so that the redesigned pickups‘ lowest part can be screwed in to hold onto the bit. I also etched the shape of the pickup on the bit. Finally, I put a set screw, so that the bit can be put onto or removed from the motor peg.

Naoto Hiéda—a colleague at the TML who sits next to me—has been working with motors and using the 3D printer to create clamps to hold his motors. At first, I thought it would be interesting to print the spooling bit that way. Tatev Yesayan—another colleague at the TML—converted my calculations to a 3D file, and I went to the Concordia Technology Sandbox, where they offer the 3D printing service.

The bit turned out nice visually, however the hole for the motor peg is somewhat filled with plastic filaments, so I will have to drill through manually. The bit also feels quite frail. I need to run tests and see how it behaves.

Handle

My next design challenge is to create a handle that will align the copper thread from the spool with the top of the pickup. As I was discussing with Seluna—an artist and technician who works with textile—she explained how a thread will naturally move back and forth on its target spool if you start from the top.

Earlier this semester, Michael Montanaro—my research director—gave me parts of a film spooling machine. The parts on the right of the black box in the image above will be of use to me. I will attach one of them to a dowel—shown in the sketch above to the left—and I will be able to align the thread vertically by rotating the dowel.

That’s my plan so far anyways.

Debugging the signal generator

Recently, Garnet Willis—a Canadian composer, sculptor, audio engineer, sound designer, and instrument builder—joined the TML. I had explained my issues with creating a signal generator, and he offered to help me out.

We spent time with his oscillator to detect what the EBow does and how the string vibrates. Looking at my circuit, he suggested that I corrected a capacitor for which I reversed the polarity, and that I look for physically bigger coils for the one acting as a pickup. I guess once I have my spooling machine, I can try to wind my own coils too.

More on that next semester!