My old system with the resin filled fiberglass ankle worked pretty good but darned ... it was very heavy. I bought a JAG aluminum ankle and shaved 20 pounds (at least) off my R2. I wasn't sure how I was going to adapt what I had in the caster to foot to ankle assembly. However it went smooth and the new design is even stronger than the old. I ran a few bolts into the ankle from the angle iron inside the foot. And .... I made a new set of exterior ankle anti-pivot "triangles" to limit the stress on the ankle when it encounters resistance. It's very strong now. After redoing and re-installing it on the frame I was overjoyed that it turned out to be perfectly level which is critical in a single caster front foot.
I completely stripped R2 down to the frame this weekend and am fine tuning a lot of the assemblies. Today I will work on the drive train and hopefully refine that assembly. It works but the foot shells are a little sloppy. I'll probably have to cut some more fiberglass from the top of them to move the motors over about 1/4 - 1/2".
We were down visiting our older son for the last week during Thanksgiving so the building has been minimal. But now it's time to kick it into high gear and get these robots ready for MegaCon.