Jointer woes...again

[Johnny4]

Hey all,

So...earlier this year I replaced all the blades in my old powermatic jointer. They are straight knife. I have run a ton of board feet through there since then. Today, I was running a piece of cherry across to flatten a face, and I had 3 loud “clunk, clunk, clunks” and it threw the board across the shop. After changing my pants, and running an autopsy, it appears that one of the blades loosened out of the jib and was attempting to take maximum chunks out of the board, hence the projectile.

Anyone heard of this problem before? Do these just come loose sometimes? Can I just realign and hope for the best?

[curlyoak]

I would talk to powermatic technical support.

[Barron]

Yes, it happened to me on my old Craftsman jointer. In my case it was just after changing the blades—I didn’t tighten enough. After patching the hole in the drywall caused by the piece That flew off the jointer, I retightened everything after going through the whole adjustment process. Never had a problem after that. I think this is a good time to use the torque wrench. And maybe the blue lock-tight. 

[Racheed]

Happened to me about 15 years ago at a customers shop. Apparently somebody before me took all the blades out  and started to replace them one by one. When they tightened to first knife there was no support from the opposite knife and the cutter head split along the axis. luckily I always keep my head below the bed when starting just for this reason . Morale of the story is never take out all the blades at once and if the gib screws are getting worn then replace them.