What the heck!

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Location
Oliver Springs, TN
On the router table I was cutting a few rabbets 3/8 x 3/8. First two went fine. next one not so well! I started the cut and got about 1 1/2" in and BANG! the board goes flying. After checking to see if I was leaking any red juice and changing my pants. I started thinking what the heck! I then started looking for what caused it to happen. I had noticed after the board went flying the router was making an odd noise. I checked the bit and this is what I found. rabbit bit face.jpgrabbit bit.jpg

I'm just glad the carbide was captured in the wood and I didn't take a shot!

What do you think happened?
 
One or two things that come to mind here.
1. Bit has been dropped at one or more times in its life
2. Manufacturing process wasn't great.
3. Router speed was to great for this bit.....
 
Carbide is brittle. If you didn't hit something really hard, then I'd suspect the carbide to be defective. Stuff happens. Good when you are only the spectator. Much hairier when you are a participant.
 
Looking at the bit I can make some assumptions

1) The braze did not fail
2) There is a clean break of the carbide
3) There is a thick strong piece of carbide that broke

From what I can see I would not blame it on cutter failure.

With that said I would look then at setup.

If the wood cocked in the cut is would grab the carbide and pull it really hard and really fast into a cut too deep for the cutter to handle and snap off the carbide. Hence, it is jammed into the wood. It could have been a quick jerky movement of shaking that pulled the wood in.

If there are sufficient mechanical hold downs for the piece (feather boards) then I might question climb vs conventional cutting. I might also question RPM or feedrate.

I wonder - were you trying to take full depth cuts and hand holding?

But - my guess is in the setup somewhere.
 
I see two good things here; one for sure and one probable. First, no injury :). Second, I had a keyhole bit fail very unceremoniously. I offered to ship it to white side just so they could check to see what happened. They unceremoniously sent me a new bit ;-) I have their rabbet set and have used it to the point where it went in for sharpening; still going strong (?).
 
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