FYI, Shapeways seems to have some quality issues with their US facility. The same parts made in their Netherlands plant are know to be stronger, this has been seen on RC10 parts made by other designers. Hopefully they will be able to improve the strength of the parts coming from the US location.
Sorry to hear that! These are intended to be replicas of the original parts, but because they are produced by SLS 3D printing they can not match the strength of molded parts. I would be happy to design a "race" version that will be much stronger but will look a bit different than the current version. If you are interested I can offer you those at a big discount when I make them. Sorry again for your trouble.