How did this happen? (Help a novice)

[Ron Robinson]

I was planing some figured maple for a print stand I'm making when all of a sudden a loud "crack" was heard. The picture shows the result. So...what happened?

The board was about 0.400" on the way down to 0.375". The pass was taking about 1/64" when this occured. I had just completed several passes taking about 3/32" each.

The knives are not new but nowhere near old. I checked the knives afterward and there was no damage. I have planed since then with good results.

Is it just one of those things? Was it something with the grain?

Help.

Thanks,

Ron Robinson


Attachment 33337

[David Duke]

Were you running it through with the grain facing away from the cut?

[Ron Robinson]

Looking at the picture, the top was the leading end. The board is about 20" long.

Ron

[David Duke]

Without looking at the boards edge its hard to tell, the grain should be running \\\\\\\\ with the grain sloping away from the cutter thereby not allowing the cutter to grab. From what I can tell it looks like it may of been ran through the wrong way and the cutter grabbed an end grain tearing out a hunk especially if the blades were beginning to dull, but then again stuff just happens!!

[Steve Cox]

Looking at it you have a bit of a grain change right there. Probably looking from the side the line of the grain runs up the point where the tear out occured and then goes down again. This is one of those things that just happens sometimes although there are ways to minimize it. Making sure that you runn the grain the right direction through the planer is one although that doesn't help much when the grain changes halfway through a boards length. Taking very light passes helps although as you have seen that doesn't always work. It is because of things like this that I order 15% over for any solid wood jobs.

[Mark Carlson]

The others had good comments about grain direction. I would also suggest making lighter cuts. With my lunchbox planer, I never take more than 1/16th and usually do 1/32 passes. Maybe I'm being overly cautious.

~mark