New CNC user. Received the 4x4 Altmill this week. Assembly went ok with no major issues. Added the MDF table with T tracks and wasteboard. When I tried to surface the wasteboard, I was getting a clicking on the x axis and an uneven surface….fixed the x axis clicking by recentering the motor and coupler but still getting what appears to be an uneven surface due to the overlap, which is set at 40%. Tried a 22mm surface bit and a 50mm surface bit but on both the overlap creates an uneven surface…..has anyone seen this?