I just commented on a post about the z axis error 313 on another post a few days ago. Mind was due to the tool started to come out a little and when it went to the flag plate that is where it would stall, after taking the tool out and resetting it's length it worked fine......but I understand there are a lot of different reasons for the 313 error, good luck in finding which one it is.
CJ
CarverJerry
ver. 1.188 Win 7- 64b with 6 GB ram @ 2.8Ghz and dual 1Tb hard drives. Rock Chuck & Ringneck vacuum system hooked up to a Harbor Freight large vacuum. Center line text, conforming vectors.