Note about box cutter set
I bought the Freud box cutter set about 2 weeks ago. I've been inside with a respiratory infection since then, so I just got to get busy on the cutters yesterday. I mounted them in my saw and made a test cut, set up on 3/8".
One side of the cut was about 1/64" deeper than the other. You could see the ridge where one blade finished and the other one started. I tried reinstalling, no change. Tried setting it up for 1/4" cut, no change.
I figured maybe I got a set of blades that had one blade slightly out of spec. I called Freud and the first guy said it sounded like my arbor threads were worn. I said let me talk to someone else. He transferred me to a technician, and he said it could be a bad set, but it could be a worn arbor from a long time of running a regular blade on it. It's an old craftsman that was my Dad's, and there's no telling how much it was used, or if there was ever a slippage problem.
The technician suggested that I first see if I could tell if there was indeed a worn spot where the inner blade would sit, and if possible try mounting the set on another saw and trying it. I didn't feel any ridge on the arbor with my fingernail, and I tried mounting the cutters on my son's little saw. It cut just fine on his saw.
I went back to my saw to look at it some more. I realized that in Craftsman's infinite wisdom (along with making the miter slot .73 inches wide instead of a full 3/4"), that particular saw came with an arbor that only has enough room on the round part between collars for 1 blade thickness.
I put one of the cutter blades on, then put the second blade up against it. Sure enough, the second blade was dropping down onto the threads where the lock nut tightens. Barely, but enough to cause the discrepancy in depth of cut.
I guess I could try to find an arbor that has a longer shaft, but the saw does fine for single blade cutting. So, since my original intent was to set up a dedicated unit with my son's saw, I can use that after I get it tuned up. By the way, that saw does have a positive upper depth stop, so I'll be ok with that as soon as I get it tuned up.
I think this is probably a very unusual situation, and wouldn't be an issue for most people. Of course, I was born on Friday the 13th, so I'm used to it. But it bears keeping in mind if you're using one of those Craftsman saws made in the early 90's, or looking at second hand ones that are for sale.