One of the main project goals of Micro Sawppy Beta 3 (MSB3) is making a 3D-printed rover design that is easier to build than Sawppy V1. Reducing the number of parts is one way to support that goal, and that’s why making the suspension rocker as a single 3D printed piece was a good thing to try and something to keep as a strong candidate for the final design.
But I’m a tinkerer, and it’s hard to resist the temptation of doing more. Especially for features that are tempting and have a good chance of being actually useful. The Rocker Deploy Pivot (RDP) is one such feature, a hinge on the suspension rocker that lets Curiosity and Perseverance fold up for their trip to Mars. I thought replicating the RDP on my own rover would help make it more portable in addition to the nerd cred factor. If so, that might be a worthwhile gain in exchange for increased parts count and assembly complexity.
Since MSB1 and MSB2 suspension rocker had to be a multi-piece design anyway, I started exploring the idea of building a RDP but it was never functional for those rovers. MSB3 is the first iteration that can practically fold up for transport. Collapsing the suspension like this does not change the length or width by much, but it cuts height by almost half. In this form, MSB3 can conceivably be small enough to be carried in a backpack.
Like many of the mechanisms that are newly designed for MSB3, it is probably bulkier than it needs to be. It added two more M3 screws In addition to the screw holding the rocker bearing. This is plenty strong so I have margin to cut back on the structure, maybe eliminating one of those extra screws and move the remaining screw closer to the pivot point. Both will help reduce bulk and reduce load on its link to the differential.