Casing the Joint

The last two weeks have included many adventures in 3D modelling. After the crashy mess that was MatterControl, Cloud pointed me to TinkerCad, a free, simple, browser-based CAD program. If you can visualise your desired shape out of simple blocks, this is the free-n’-easy application for you. What I need, for the time being, is a simple set of boxes that are as low profile as possible given my electronics set-up and easy to configure or re-configure. I decided to use translucent ABS plastic filament to print the boxes so that the LED’s would remain visible through the box and that the light sensors inside of the Arduino Nano 33BLESense might still be useful.

R O U N D B O X

I started with this rounded box (after a few iterations and test prints). The holes were originally square, but I hated the way they looked. These rounded holes look mildly more elegant than the plain square holes, while still fitting the component connectors through them. While I like the shape of this box, the dimensions are both too large and too small to comfortably fit the redesigned electronics. I adjusted the button/toggle sensor configurations with the coming of the post, which rendered the longest oval hole too short. And so the process moved on.

S M O L B O X

The keen-eyed might see a small design change in the base plate of this design. The small cut-out on the right side allows for my solder traces for the flex sensors to sit flat in the minimum allotted space. It also functions to hold the plate in position inside of the box. To give the connectors more room, I widened the profile of the box but reduced the height. There is a 1mm thick section on the top of the box above the LED’s and photo-sensors to ensure that they remain visible/useful. I rounded the corners of the rectangular holes as a compromise between the cutesy oval hobbit-hole doors of the semi-circle box and the utility of a square hole. I added some internal supports to the underside of the holes, which further serve to keep the electronics in place. This makes the sensor connectors easier to insert as the module doesn’t slide around on the inside.

S Q U A T

Aesthetically, I’m not very keen on this design. When I am ready to solder the Arduino directly to the board, it may do very well. At the moment, it just looks like a squat hill. Using black ABS would reduce it’s perceived size somewhat; however, I want to aim for a more “organic” design. Something more friendly to the eye, elegant, and welcoming of touch. My CAD skills are currently not at the level I need to express this design. So, it is utility for now and elegance for later on.

3D printing is almost like magic, for me.

Today I moved on to reconstructing the battery housing in the same image. The older housing, thrown together by Cloud looks like this:

T E S T I N G

It’s slightly too high and does not secure the battery components in place as I would like, so after much measuring and tweaking of sort-of circular shapes, I will move on with this design.

C O N F O R M

I wanted the box to conform more to the components within to reduce the apparent size and secure the objects. Having the connection points on the base plate and a friction fit lid may still prove a questionable decision. For now, it reduces the apparent size of the box in a pleasing way.

By the way, if you haven’t had the joy of listening to the noise music that is produced by a 3D printer, it is truly glorious. I sent a recording to a friend whom described it as, “like an modem on ketamine”. Personally, it strikes me as alternative-to-alternative dance music, and where will you be when the bass drops?

I think about the God of Plastic a lot at the moment.

There have been some problems which have been worked out by Cloud, as the 3D printer’s owner. He had previously been printing in PLA, which has very different print requirements. As of the different reels of ABS we have used, each manufacturer and colour has slightly different requirements too. Generally for ABS, the temperature of the extruder and the heated print bed need to be raised, it must be printed slower, and the filament needs to be fed at a 110% overfill rate for useable print quality. One problem that we have not fixed is that some of the translucent filament seems to burn, or otherwise discolour, at random intervals (seen in the image below). Thankfully, this has not appeared on the top layers of any print jobs. Additionally, it is winter, here in Melbourne, and the cold air causes the print jobs to curl and warp when a consistent temperature is not maintained. We are working on a remedy to this problem by building a clear polycarbonate surround box for the printer.

C R I S P Y B I T S

I have resewn the gloves to test the PowerMesh fabric (see another upcoming post about design materials for the gloves!). The assembled version looks like this:

Why did I forget to buy Velcro from Lincraft?

I’m still coming to grips with whether I like the placement of the switches and toggles. So, nothing is designed to be set in stone for now. The next stage will be using these gloves to compose a few pieces and evaluate how they function as an instrument, as a performance device, and what effect they have on any sense of embodiment in performance or composition. These small works will be solo and duo pieces using different gestural and retrofitted instruments. You can see the P-Bow that will feature in one of these, designed by Cloud, here. The gloves will remain as USB connected devices until the BLE capabilities have been ironed out. I’m more presently concerned with them as a tool.

Following the creation of these small works (which will be shown on my YouTube channel here), I will reduce the size of this iteration by soldering the components directly to the board and adjusting the housing. This should make the electronics more robust as well as more wearable and elegant. I will likely move to a lower-profile battery type, such as the flat lithium-ion battery cells sometimes found in powerbanks. Then I will work on any extra sensors that would be useful to incorporate before venturing into the world of custom PCB design.