At the Rogue One premiere Chopper experienced a failure of a shoulder bolt that nearly caused a catastrophic crash. So, the entire month of January was spent beefing up the shoulder linkage and redesigning his stance to use a better center wheel. Here he is a Pensacon 2017 and everything worked perfectly.

You can see his new stance and wheel here. He glides effortlessly now and his runtime increased from 5 hours to over 8. By the end of day one he was running strong on the original set of batteries. I barely noticed any slowdown.