I’m an aeromodelling enthusiast currently working on a fixed-wing aircraft. To power it I created this custom design of an electric ducted fan (EDF), which is driven by an 800W RC brushless inrunner motor.
For this kind of modelling applications, stability is the biggest challenge. To make the EDF perfectly functional, all the parts had to be accurately designed, printed and balanced. That’s why I soon dismissed the idea to print the parts with FFF/FDM since the motor can warm up to 70°C at high speeds – temperatures, at which filaments start to become soft. I also noticed a significant wobble with PLA test prints, so I can’t really recommend that. PETG might have been another option, but its handling with support structures seemed to be too much of a hassle.
Since I’m working as an engineer at Sintratec (manufacturer of SLS printers) laser sintering seemed like the obvious next choice. I decided to print the parts on the Sintratec S2 with PA12 – a very resilient and durable material with perfect characteristics for further mechanical processing. Printing took around 20 hours, the only post-processing required was to de-powder the parts.
Here’s the video that shows the final testing and adjusting I did with the EDF:
I wanted to measure the amount of power the part could handle without being damaged. For that I tied the EDF with a cord onto a rail and fixed it on a table. With proper distance and safety goggles I began to accelerate.
During the test the motor power peaked at around 1400W, with the EDF withstanding a speed of circa 30’000 RPM. An impressive result, considering the printed parts as well as the motor survived these forces without any damage.
Turbine running with smoke.
Screws for combining the parts, lead balls for balancing the fan, 800W RC brushless inrunner motor for powering. Additional hardware like an ESC, transmitter and receiver are necessary to control the EDF.
The printed EDF consists of three main parts plus a mount. First, place the motor inside the housing, run the cables through the designated holes and then screw the motor onto the respective structure. After that, fix the blades on the motor and attach the spinner – depending on accuracy, it can only be pressed on. Lastly, attach the mount to the EDF.