LipSync Update: 3D Filaments

In a project dependent on 3D printing, one of the most important things is the material we use, and what materials will allow makers to create the best possible LipSync. Here’s a rundown on the printing filaments that we’ve decided to use, and why:

Filaments

  1.75 mm ABS filament.

LipSync Casing

An June iteration of the LipSync casing created using “regular” ABS.

We initially began using ABS (Acrylonitrile Butadiene Styrene) (new window) as our filament. A styrene-based material, it is easy to print — something that can vary from filament to filament.

For a prototype, it might have been tempting to use PLA (Polylactic Acid) (new window), an organic plastic, which is non-toxic and has no scent. It’s also easy to print, and is thus, popular among makers for prototypes.

But we’re not just planning to make a prototype, we’re making a usable product — a usable product that can be replicated by makers across the world.

PLA has a low resistance to heat and temperature, and lacks the appropriate strength. On a hot day, it could melt and warp. That would be no good!

ABS, on the other hand, does have high temperature resistance, and is appropriately strong. But “regular” ABS is not food safe, and that does make for a bit of an issue.

1.75 mm food safe ClearScent ABS filament.

1.75 mm food safe ClearScent ABS filament.

Don Danbrook 2

The blue cap that holds the mouthpiece uses this kind of filament.

For any part that is in contact with the airstream (for the sip and puff (new window)), it needs to be food safe. PLA, once again is food safe, but the only version strong enough for our needs is high strength PLA, and that, ironically, has not yet received a food safe rating.

Luckily for us, there is a food safe variant of ABS — ClearScent ABS. Like the name implies, it lacks the scent that generally comes with ABS printing, and is non-toxic.

LipSync head with the chambers made out of conductive ABS.

Above: The LipSync head with the chambers made out of conductive ABS.


Below: The inside of a rear chamber created using conductive ABS.

Inside LipSync head

Now if you notice in most of our recent pictures, the LipSync head is black. That`s because we aren’t just using “regular” ABS for the shell.

Because the LipSync will likely be used in hospitals, we wanted to create a housing design which would block harmful electromagnetic interference (EMI) (new window)emissions. We need it to be conductive, so it creates a Faraday cage (new window) around the electronics, blocking those EMI emissions, and creating a static discharge, so that it doesn’t build up static electricity (where a touch could zap the electronics inside). The original design did this because it was metal — unfortunately, we can’t print pure metal.

Initially, we used a new filament on the market, conductive graphene. It printed high quality and the conductivity was very high — exactly what we wanted. However, it was difficult to work with, and very expensive. The maker would have to switch nozzles just to use this material. We don’t want to put makers through that.

So we found conductive ABS. It was a bit tricky to work out, we had to do a few iterations, but now we have it down — we’ll provide printing instructions for makers. Though it is less conductive than conductive graphene, it appears to be conductive enough. However, we are currently testing right now.

For those of you thinking about making a LipSync, we’ll have assembly instructions — don’t worry. You don’t need to keep track of every snippet of info and piece it together yourself. There’s actually an assembly instruction manual that you can access now at the bottom of our Hackaday project page: https://hackaday.io/project/13424-lipsync. (new window)