The story of KiwiFil
KiwiFil is the business branch of our life, but we are a lot more famous for our electric racing efforts. We held the world speed record for electric motorcycles for over a decade, and just built a brand new motorcycle with 1,000 HP to challenge the overall world speed record for motorcycles - the "Green Envy". You can read that story if you click here.
Electric racing is what brought us together (that's yet another story that you can read here), but it was a job offer at the University of Auckland that brought us to New Zealand. After two years of teaching engineering design and CAD (computer aided design) to 1,100 first year students every year, I concluded that the university wasn't the place for her. Not sure what to do instead, she decided to take a year off and focus on the Green Envy and racing. Then the pandemic hit, racing was cancelled, and the boredom of lockdown is what lead us into this new path in life!
Photo: Eva, Bill, and the 1,000 HP electric motorcycle "Green Envy".
A new life for an old machine
In March 2020, we found ourselves stuck at home with a raging pandemic sweeping across the world. The land speed record attempt in Australia had been cancelled, and we were back home in Auckland, New Zealand. While we were extremely thankful to be in New Zealand, we were bored and looked for a new project.
At the same time, international supply chains were interrupted and it was difficult to get things like 3D printing filament. And we use a lot of 3D printing filament! That's were the idea of starting to manufacture 3D printing filament was born.
During the 6-week total lockdown due to the pandemic, we weren't allowed to go to our workshop. With three 3D printers at home, we thought of it idea of 3D printing (!) a 3D printing extruder. A bit of searching online lead us to Michigan Tech University and their "RecycleBot" project - an open source, desktop filament extruder.
With many design improvements along the way - most of them shared with the original research group - a couple of months later we had our own filament extruder.
We went to look at it, and bought it on the spot! This is how happy we were. :-D
But then we had to bring it home. The machine is about 10 meters long with the coolant water bath and the "haul-off", and all the parts are hardwired together. It took us a day to just label and disconnect it all.
A friend in the show business industry helped us to bring most of the parts home...
...but the main extruder was too heavy for a regular lift gate.
A wrapped it for a trip across town....
...and hired a "Hiab" (New Zealand slang for crane truck) to bring it home. Here is the precious delivery!
To be honest, I have never - before or after - seen such a big smile on Bill's face.
In its new home!
The final straw!
The first task was to remove the complicated die (tool) that made the drinking straw with the stripes on the side. We can't even guess how much this die originally cost, but it was of no use to us, unfortunately.
After that, we had to clean out the remains of the last run of drinking straws.
The extrusion screw is over 1.5 meter long, and 50 mm in diameter. There are of course much larger extruders out there, but this is still a big one!
The Green Envy electric streamliner had to be moved out to its sea container to fit this new arrival.
Cleaning out the last of the drinking straws by pushing through new material.
Making filament for the first time!
Learning every day. There is a lot of black art in plastics manufacturing. You wouldn't think the exact temperature of the water bath matters, but it does. We learned that the hard way.
We had shirts embroidered! Things are getting real!
It took lots of clever innovations, and lots of 3D printed parts to finally get to make filament! We didn't mention it above, but the biggest job was actually the pulling and spooling end of the machine. The original setup was to pull the drinking straw and cut it to size. A cutter would be of no use to us - we want to continuous filament!
The size of the filament is determined by the pulling speed. If the filament comes out too thick, you pull faster. If it comes out too thin, you pull slower. This is all controlled by a laser gauge measuring the filament, and a micro controller adjusting the speed. Simple in theory, thousands of lines of code in reality!
The entire process is controlled by a "Teensy" (high performance version of the open source Arduino micro controller) hiding inside the purple 3D printed box. Purple is our signature colour because both us like purple. We thought making the machine purple would be fun and cheerful. After all, it doesn't matter - pretty much all colours have the same strength. What is a bit creepy if you think about it, is that a lot of the filament used to make parts for the machine, was made on the machine. It is self-replicating..... *suspenseful music playing*
Making filament is one thing, selling it is a completely different thing! We extrude onto 20 kg bulkspools, and then re-spool to smaller spool. However, coming up with a spool design was easier said and done. You can buy injection-molded plastic spools from Alibaba, but we wanted paper spools.
Eva tried a number of different designs and manufacturing methods, but they were all too slow and difficult to manufacture. she 3D printed a manual spool side cutter, I cut spools in the band saw, with razor blades, and even bought a cheap laser cutter.
This idea was to use old plastic "core flute" boards. It could have worked, but was almost impossible to cut and glue.
This design had 3D printed hubs holding it together.
And this became the final design! You can read about how they are made using local suppliers here.
A very proud moment when we had our first sample spools to send out to beta-testers!
And an even prouder moment when KiwiFil filament was available in store for the very first time in March 2021! If you want a spool today, pick it up at Surplustronics/Sound Division in Albany, Auckland.
This was our very first retailer and will forever have a special place in my heart. Eva made the store guys an Easter Egg in the shape of their logo to hand over when I delivered the spools to the store. :-)
We are looking forward to many years with KiwiFil and a continued exciting story! We hope you will follow us along.
The other half of our life is our racing effort, which was led us into 3D printing in the first place. You can read that story here.
// Eva & Bill