Rather unusual results. Are you checking clearance between punch and die with a die light to verify alignment AND geometry? Are you checking the edges of both under magnification for contact or "skid marks" on the sides just below the cutting edges that show the rubbing condition of bad geometry or misalignment?
What's the material thickness and die clearance per side? Use of a die light (small light source) with the die flipped over (parallels between the top/bottom so the punch just enters the die) gives a quick visual check without having to measure a contoured edge. Look up how to do this. Something is odd/off, best to verify the die before giving material any doubts.
Any excess play between the leader pins and the bushings? Did you test this?
You did this before with satisfactory results, now you can't. Something ain't right here. Let's work through this.
Im still working on learning... Im self/forum/research taught... so I usually learn something every post I read. Id like to think Im not an idiot, but I know there is so much I dont know - and suspect its getting me. Like all the tricks of the trade and standard knowledge for a die maker... I appreciate your post... gives me more things to look into and ideas for how to check stuff. Ive been looking at edges with a 10x loupe but its not a fancy one. I have a 10x microscope another machinist gave me just recently, but have not figured out how to get the light right and maintain focus to be able to see. Im sure it can be done, but Ive not figured out the correct way to hold my tongue with that thing just yet :P
Ive done some looking at scuff marks, using a sharpie around the punch and sliding through the die plates... there always is a little, but doesnt seem very consistent - which led me to think it was fairly symmetrical... but thats more an assumption. I need to get some gauge pins with smaller increments. All I have is .001" increments (+ style pins - cheapies). The one dimension (width) I can check with the gauge pin - at least to the accuracy of the pin and my Mitutoyo anvil mic. It leaves some to be desired though with the pins being only .001" increments. I made to punch pieces using the same program/offsets, but on two different days... came up with .6142 width on one and .6145" on the other. Im making a third today if the lil one will give me the time (daddy duty, home shop, wife works, and a 6 year old make it tough sometimes) - and purposefully aimed for .0004 larger via changing the wire offsets on skim passes by +.0002. Im going to take those three, and one of the die plates from the ones I made, and try the light idea you mentioned. (will research that more here in a few). But also, having one, that if it turns out at the planned .0004 oversize, if I can still fit it in the die plate - Ill know I just tightened it up some and at least have something to try.
I agree, something is up and I would wager its me... and having made successful ones routinely on my 92 Mits SZ, out of A2, when I wasnt handling the dowel pin holes the right way - to now, using D2 and cutting on a 96 Mits FX10 that had new screws a couple years ago, and wiring out the dowel pin holes, and still failing over and over - Im looking at variables that have changed... The new to me as of a year ago FX Machine *should* be better, and from other stuff Ive cut with it, I feel that it is, and cutting a test square and checking with a tenth DTI on a surface plate leaves me seeing that it is better than the results of the same from the SZ machine. But I guess that could be very dependent on where on the table the cut was made. D2 should be more abrasion resistant, and why I went that way instead of just getting more A2 when I made blanks - but have learned quickly it doesnt grind as easy. This has my attention as I wonder if my lack of grinding skills is leaving me with too much heat into the plates, and thus softening them. So Im working on coolant for the grinder and seeing if that helps. I am tempted to try creating the slot for the material on the wire on one of them just to see... Instead of grinding .010 off of the top plate and bottom plate to create a .020" gap for material, rough in with the wire and then skim a few passes on the bottom plate where the cutting occurs. Have also started looking at CBN grinding wheels, but would need to get the coolant working for sure as well as get a brake dresser if I try that route.
I think Im focusing on the material a bit more, not because I suspect the material itself, but that I suspect since its tougher, that Im not doing things correctly for the different material, and in the past just got lucky with the A2 being tolerant of my uneducated grinding ways
The material is between .009 and .015 thick - same punch to cut material anywhere in that thickness range. No issues punching a piece of printer paper (tried just out of curiosity - but paper wont delaminate either or at least that I can see)
Im assuming leader pins and bushings are more or less guides for the punch as it goes through the die plates. The ones Im making are not that sophisticated. The top plate is the guide. Only 5 pieces to the punch set up not counting dowel pins and SHCS's - The punch, and soft rod as a "handle", the top and bottom die plates, and the bottom plate with a milled pocket for clearance for the punched item to fall into/through. Yeah... I know, design flaw... but my "market" cant and wont pay for a proper punch.... no way no how. Im sure thats not helping me with the delaminating issue, but having made many successfully in the past from A2 has me thinking that its still a viable design despite its flaws - I just have to figure out what I am doing wrong.