Top layers peeling off

I printed some parts last night, ABS, 0.14 layers, similar to many I have printed before. There was slight warpage from the raft releasing, but the major problem was the top layers spontaneously peeled from the honeycomb fill and edges. Not sure exactly when - it was like that when I looked this morning, already cool. There were 4 such surfaces in this print, each of them peeled exactly the same. It falls off at a touch, easier that removing the raft. 

Anybody know why?



I believe I discovered why. There was a cross-under on the reel. I had printed multiple parts over multiple days from the same reel using maybe half of the reel since it was loaded. Apparently it was able to pull the filament anyway, until these layers on this print. It must have skipped a layer or two, then was able to pull the filament free and finish the tops. I only discovered it on the next print, when it got half way through and then finally jammed. 

It seems unlikely that the factory could put a cross-under half way through the reel, so I must have loaded it that way, days earlier. I try to be careful about this, but it must have happened. I was fooled into thinking that a tangle on the reel would result in the print stopping completely, not skipping a couple of layers and then finishing. 

Thanks for coming back and letting us know, will add that scenario to the troubleshooting list