I spent the last week running a batch of parts. When it was all said and done, I ended up losing 20% of the parts, and I have no idea why.
Before I started the batch run, I spent some time optimizing the gcode, and tweaking the feeds and speeds. Once I started the batch, I didn't change anything, other than to take the finished part out of the vise, and put a new blank in. Every once in a while, one of the tools would cut about .050" too deep, but on the next tool the Z height would correct itself. I would take that part out of the vise, put it in the trash, and the next part would run just fine.
I'm at a complete loss on how to explain this. I hope some of you can contribute ideas.
Tormach 1100 series 3, with ATC running on Mach 3.