While I was preparing to do some re-sawing on my (Grizzly 550) bandsaw yesterday I had unique- at least to me- experience. I had just reset the guides and tested with a rip cut just to be sure all was well.
While ripping I notice the blade doing some crazy stuff; it would push forward and then move back, almost like an orbital jigsaw motion. I stopped the saw as quick as I could and opened the wheel housings and rotated the wheels by hand. Sure enough the blade would track the center and then shoot to the left side of the upper wheel and then go back to track to center. I of course suspected the weld and sure enough this was occurring right at the the weld.
I looked at it with a 25 cent harbor freight magnifier and the weld did not look particularly healthy. Evidence enough for me; time to replace it. When I took the old blade off and put just a little hand pressure to it, it broke.
Bandsaw blade breakage may be as statistically inevitable as car accidents and part of the price of admission, but I am sure glad I didn’t have to pay the price today.
If there is a moral here I guess it’s that safety begins and ends with observation. I wonder how long this had been going on likely to a lesser degree, before I noticed. I will surely pay more attention in the future.
If your saw starts doing something unusual, it’s likely not going to prove be an ‘improvement over normal behavior’. I lost 1/2 the day getting a new blade, but avoided (at the very least) a very sudden heart rate increase.
-- I'm 58. In my mind, I still feel 28. Until I do something physical; then I feel 78.