I sometimes mill my own lumber from windfall on my property - in the first instance somehow I managed to put a single piece of near green lumber (~40% moisture) in the same rack as some lumber I knew was dry.
A few weeks later I needed some scrap for something, grabbed the piece closest on hand, pushed it into the blade and immediately triggered the wet wood alert and the blade spun down slowly. I knew that the wood wasn't wet, so started the saw up again and pushed it straight back into the blade only with more force, triggering it straight away.
Second time was due to cutting a lot of pitch heavy pine over an extended period of time - it built up on the cartridge and after a blade change that I didn't check the clearance on, it bridged the brake with the blade (i assume) and triggered on start up. (It comes with a tool to check this clearance after a blade change - I of course did not follow the instructions).
You can use wet wood or pressure treated lumber or even foil coated acrylic - but the key is that you need to be expecting this, and you put the saw in to by-pass mode.
At that point, it's just another dumb saw that will chop your finger off, but it won't trigger the cartridge, and you can make what ever cuts you need.
The way it tries to determine if it's wet wood / a body part is the capacitance change. Slightly different profile which they can use to make an educated guess (obviously erring on the side of caution).
This is why for some time they would give you a free cartridge if yours triggered on flesh - they wanted the data on there from real-life flesh contact to improve their calculations.
> This is why for some time they would give you a free cartridge if yours triggered on flesh - they wanted the data on there from real-life flesh contact to improve their calculations.
The automatic defibrillators manufacturers also will often send you a unit for free if you used your unit for an actual defibrillation. Same idea.
Ah, that explains why there is so much electronics in the cartridge! It seemed a bit like overkill, but returning the cartridge will get them their data.
You can manually disable the auto—trigger mode in those situations though (bypass mode).
It also doesn’t like anything conductive - so anything coated with Mylar, any kind of conductive dust or debris, etc. is also a crapshoot.
Very much edge cases though, unless you’re dealing with a lot of randos. A workshop I used to share had a wall covered with sawstop ‘trophies’, due to people doing weird stuff.
I've triggered one by touching the blade too soon after it has stopped. There is a short delay between when the blade stops and when the brake is disabled. I've also had one trigger on a heavy miter through some gnarled 8/4 walnut.
