Review on Enhanced Mortise and Tenon Jig - Precision Drill Template Set with Hollow Chisel Bit Attachment by David Sharma

I thought this product would be great but when I tried it I was very disappointed. On poplar (soft hardwood) they made peaks and grooves; fairly easy cutting but not accurate, there was a slight deviation in self-centering. I've tried ash (hardwood) and it was horrible, the wood would move even when using a square guide unless I clamped a piece of ash onto the square guide and even then there was the same self centering discrepancy. I returned the item after several days of trying to get it cut properly, showed it to my professor and was told it was best to return the item if possible as it would never cut accurately.