A little while ago I modified an iRobot Roomba 630 into a high speed radio controlled vehicle. Dubbed the ‘Vroomba’, it was fun and fast, but there were quite a few design flaws that made it difficult to drive. That first video got a lot of eyeballs on it and I had some excellent suggestions from viewers on how to do it better.
The first issue to tackle was replacing some broken parts with new parts made from stronger materials. Bambu Lab sent me one of their X1-Carbon 3D printers and this opened up the opportunity to print parts using high temperature materials. So I went with their Carbon Fiber Reinforced High Temperature Nylon (PAHT-CF) which I thought would be perfect. I printed the motor/gearbox mounts and the wheels using this filament. And I have to say, I was very impressed with the stiffness of the printed parts. I used the same Smooth-On urethane to mould the tyres onto the rims, but this time I also used Smooth-On’s urethane pigment dye which gave them a much more vibrant colour than the last lot. I bolted it all back together and it was time to add some aero for more downforce and grip.
Inspired by supercar designs, I CAD designed some very over the top aero in Fusion 360. This included a front splitter, wing, belly pan and rear diffuser. I 3D printed it all using the same PAHT-CF filament. And that all bolted onto Roomba using 3 mm fasteners.
Lastly, I added a new DumboRC radio that came with a receiver with a built-in gyro that could help me keep it in a straight line. This radio has tank mode which works with differential steering, when I tested the gyro, I found that it doesn’t work with tank mode as it can only control one channel.
I headed to the track to test it all out. The Wodonga Radio Control Car Club have a a great little touring car track that I used to tune the handling. After dialling it in there it was time for more speed runs, but it didn’t quite go as planned. I couldn’t beat my previous record of 57 km/h and the Vroomba exploded into pieces when it hit concreate head on at 44 km/h. But on the upside, the PAHT-CF parts survived unscathed which is testament to their strength. It was still a fun project and it’s given me plenty of ideas for the Vroomba Mk 3!