I'm trying to cut a 10 TPI ACME LH thread in EN8 with carbide insert on my Harrison M300 and I'm getting variable results. The photo attached shows the problem with the thread profile - in this photo the chuck is on the left and I'm cutting from left to right with 14deg on the compound. Cutting depth on each pass is approx 0.1mm to a depth of 1.3mm then much smaller increments to approx 1.4mm. The insert has been squared to the chuck, there is some wear in the bed and cross-slide though for the cut the cross-slide was locked and feed was solely by compound (which had been tightened up). The main leadscrew, thrust bearings and half nuts are in good condition. It's almost as if the 14deg is too much but I've double checked that. Any suggestions greatly appreciated!