First of all: thank you so much for this wonderful project! I have tried for weeks to remove the key from the J1 motor shaft using locking pliers, as described in the AR3 manual. I was able to get a good grip, but it. does. not. budge. 😥 I have then tried to remove it using a cold chisel. I've chipped a corner of the key off, but it does not move at all even when hammered with the chisel. Any ideas on what to do? Do you know if stepperonline has maybe changed their product recently?