Kickback safety share – Sawstop dust cover
I was using my Sawstop, with dust cover attached, to cut a bit off a board about 3/8 thick (x8″ W x 4′ L). Then I tilted the blade 45 degrees and moved the fence over about 3/8. Properly positioned so as to not have any kickback contact me, I made the cut no problem. Then I went to turn off the saw. While my left hand was making its way to the off switch, I gather the loose plastic pieces on the dust cover that normally come down either side of the blade (inside the main rigid blade cover) must have caused the cutoff to get trapped and all of a sudden I had a ~3/8 triangular splinter about a foot long through, and then embedded in most of my palm (parallel to palm).
This seems to be a rare form of kickback. I am guessing a wider cutoff would have engaged the little springy black teeth that are part of the DC/riving assembly. I don’t know if other saws may have similar DC assemblies that could cause this. I’ve attached a picture showing the cutoff and regularly spaced saw marks inside the DC assembly, which measures about 7/8 total. So with a blade in the middle, not much room.
So, if making a tilt cut that will leave small cutoffs that can get trapped *not* on the fence side, consider just use the riving knife without dust collection. Or balance on one foot and turn the saw off with the other 8-). Stitches come out next week…
Replies
Am I reading this right? The protection devices, at least partially, caused the kickback?
Schnikies!
Sorry for your injury! IMO using the DC blade guard on a skinny 45° cutoff is not safe. Assuming your fence is to the right of a left-tilting blade and that you're taking the bottom corner off the stock, when the cutoff comes free it's trapped next to a ramp formed by the guard that's angled towards the spinning blade. Your instincts that it might kick back were solid, your luck was not. A shop teacher once told me "If kickback's on your brain, something needs to change".
On a 3/8" cut those little black teeth never got anywhere near it... they'll only engage the top surface of a board, and only if the blade is set to just above the board. (SS PCS user over 10 years)
Agreed. I transitioned from the straight cut to the tilted-blade cut without contemplating the change in circumstance. Kickback wasn't necessarily on my brain more than any other day, but generally guidance is to not position torso right behind blade when possible.
@chiwoodworker: root cause analysis is per above, the kickback was caused by the user not accounting for new situation. If I walked in the shop and thought, I'm going to make a tilted-blade cut today, first thing, I might have had a second look at the DC device. Or if it wasn't there, I might have thought to not put it on. As it was, I think I just left everything running and tilted the blade.
First kickback in 20+ years, hopefully spread some awareness.
Majority of my cuts on my TS are thin rips so i never use that device for this exact reason.
Sawstop officially states you should be using that guard "Whenever possible"
They recognize that its not always a good idea though specifically on those thin cuts.
That guard can also come into contact with the blade and straight up explode...
I think its a good idea to use if your doing a lot of panels and such but for thin cuts only a riving knife and standing clear until the blade has stopped is best.
Glad your ok. Really makes you stop and ponder when it happens.