Scan does not always start at base home angle

[dcyoung]

Expected Behavior:
At the end of the base reset phase, the base moves slowly CCW and it should stop just as it hits the limit switch.

Observed Behavior:
For some reason, it occasionally hits the limit switch... continues CCW slightly and then jerks back to end up slightly in front of the limit switch (ie: CW from the limit switch) and begins scanning from there.

Starting the scan a few degrees in front of the limit switch means the base will hit the end-stop before it has completed a 180 degree movement. The last few scans are taken with the base pressed against the end-stop, jittering back and forth as a result.

[dcyoung]

#26 is related to the base getting stuck on the limit switch and jittering back and forth. While that issue (now solved) often occurs in combination with this issue, it does appear to be distinct.