Once general suspension geometry of Sawppy the Rover had been sketched out, it’s time to start building suspension components. The general construction technique has been documented, it just takes a lot of sweating the details to make everything work together as intended. Like any design endeavor, the first draft is never quite right and every part takes a few iterations to mature.
When a 3D printed plastic part turns out to be flawed for one reason or another, the plastic is effectively lost. Many people find this wasteful, some are working to recycle the plastic in some way, but nothing practical just yet. I’m not interested in recovering the plastic right now. The bearings I had pressed into the plastic components, however, are another matter.
Unlike the plastic, the bearings are easily reusable in follow-on design iterations of the part. Since the plastic is forfeit anyway, we can cut plastic apart to recover these bearings, but such cutting has to be done carefully to avoid damaging the bearing. It would be better if we can remove bearings in a way that’s more reliable and less likely to cause damage.
To help with this process, I’ve started incorporating access holes into suspension components that are useless to the rover itself. In fact, it might be a bit detrimental by weakening the component to some degree. The purpose of these holes is to provide physical access so there’s leverage to pry these bearings loose without cutting. Here’s one of the earliest steering knuckles (right) next to a more recent iteration (left) that provides an access hole to push bearings out for reuse.
In theory, once component design is final, these holes can be deleted so I can print a seamless and full strength part. In practice, I’m probably never going to stop tinkering with the design or, even if I do, I don’t foresee throwing away a perfectly functional part purely for the sake of printing one without the access port. I may release designs without bearing recovery port for others to print, but my own rover development chassis will always be Swiss cheese.