Slightly off topic, but the worst engineering design of Bandai that I ever encountered was the hip joint for the Chogokin Gipsy Danger. Now that was a sure fire time bomb, I can't imagine how it will not break itself over time, even with good materials. Basically I found that my Gipsy Danger's hips were both loose after keeping it boxed up for a few years. Turns out the reason they were loose was because the plastic peg/cap that holds the metal hips together had snapped. I wish I still had a picture of it, but basically they designed the hip to be made of 2 metal halves held together by a plastic cap and with a screw inside. Normally you wouldn't think this was a problem. But they had the idea that the best way to give friction to the metal hips was to sandwich a super high tension spring inside. This spring was so strong, I could barely squeeze it with my bare hands. So you can imagine that having so much force being exerted on a plastic piece will turn out. I wish they just used a screw with a bigger head or better yet, done away with the spring idea.
I just thought I'd bring it up because hearing about the spring being used to create friction in the 171 reminded me of Gipsy Danger's exploding hips.