Read Part 1 of this project here

Read Part 2 of this project here

To recap, Delrin, Nylon, HDPE and a host of other engineered plastics can already be found in various places on many experimental aircraft. For the more adventurous among us, ABS, PETG, and even PLA are also being utilized where applicable and possible.

In part 1 I set out to determine if I could successfully design a replacement for Delrin for low-heat low-load high-friction applications with PETG or ABS. In this instance, I set out to utilize a 3D printed wear surface to replace my torque tube cap.

In part 2, I fabricated the torque tube cap then installed the following assembly. 3D printed PETG plastic which includes pressed aluminum inserts and cap machined in 6061 aluminum:

 

Installed:

15 Hour, 30 Hour, & 45 Hour Checks

There has been no measurable distortion or perceptible wear on the 3D printed PETG part after every inspection. The minor cross hatching from the initial sanding is still visible in the bearing surface of the torque tube cap below after roughly 45 hours of service:

This assembly was initially installed during the deep of winter in Colorado, however the current daily temperatures in July are in the high 90s every day. Due to the lack of wear and dimensional stability, I am becoming more and more confident 3D printed PETG can meet the needs of limited load bearing wear surfaces while withstanding typical temperature ranges found outside the engine bay.