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Totally off-topic, but the automatic blade brakes on modern table saws are really cool. It runs a current through the blade, so when something moist like your f

by snazz 6y ago

Totally off-topic, but the automatic blade brakes on modern table saws are really cool. It runs a current through the blade, so when something moist like your finger or a hot dog gets too close (maybe using capacitance?), it automatically drops the blade and instantly stops it with a single-use brake mechanism. Better to destroy the $100 blade-and-brake assembly than to lose a finger.

roel_v 6y ago
Those videos show up in my Youtube feed the last few weeks too (although these saws have existed for many years now), but I still wonder - why do they always use hotdogs in the demo videos? Can't they find anyone who's willing to risk a finger, or is it something much more boring like OSHA rules or something?
- throwaway0a5e 6y ago
  >or is it something much more boring like OSHA rules or something? I think it's more like if you understand the tech well enough that you are willing to risk it you likely understand how not to stick your hand in a saw in the first place, don't see the value add and don't wind up working for these people. Also there's probably a pretty big social aspect of it. The guy willing to stick his hand in the saw for the demo video is gonna get shunned by most of the kind of people who want to work on tech like this.
- jacquesm 6y ago
  Technology can fail, so why risk it? I'd not trust my fingers to someone else's design either, no matter how good, though I'd be happy to have that system installed on every table saw. But we'll have to wait until the patent expires. Even table saw blades that are protected like that should still command healthy respect and anybody that wants to show off that capability is throwing the dice. It's a bit like driving into a wall at 50 Kph to prove that airbags work. Sure they do. But you may still get injured.
- grumple 6y ago
  There’s a video of the guy who makes them using his finger. There’s another on their website, search for sawstop. But as for others, tech can always fail so why risk it? Also it costs $100 each time you do it so it’s not like a ton of people want to waste the money.
Unklejoe 6y ago
> something moist like your finger I wonder how well this would work in a real life scenario. My dad does autobody work, and his hands are like dry, cracked stone. They probably have very high electrical resistance. I'd imagine a wood worker's hands to be similar.
- jacquesm 6y ago
  The first nick will conduct plenty due to the blood.
- jagraff 6y ago
  Once the blade started cutting through the skin and got to blood vessels, the resistance would go way down, so it would probably still work - just with a larger/deeper cut than more conductive hands.
Igelau 6y ago
How am I supposed to cut my hot dogs now?
- DarkWiiPlayer 6y ago
  Completely dry them first, cut them, then let them soak in water overnight. Can't guarantee they'll taste 100% the same, but you get around buying dedicated hot-dog cutting hardware.
wmeredith 6y ago
These saw brake systems aren’t on “modern table saws”. This system is branded and patented and only exists on Saw Stop table saws (no affiliation). If I recall correctly, the inventor took the tech to the big saw makers when it was first in invented and was turned away, because of some combination of he wanted too much money and they didn’t want the liability of marketing a “safe” table saw. So he started his own company. The tech is truly something incredible. It uses a disposable cartridge with a shotgun-sized charge to ram an aluminum matrix into the bottom of the spinning blade if it detects current (oily skin touching the blade closes the circuit). It stops it in thousandths of a second and your left with a nick instead of maimed. It ruins the blade and the cartridge. You’re out ~$150 if you trigger it. Small price to pay for keeping a finger.
- snazz 6y ago
  Huh! Thanks for the correction. I was under the impression that it was more widespread. I forget the brand of the table saw I used most recently, but I do know that it has that feature.
  - speg 6y ago
    Saw Stop is the original one. Bosch does have their own version called Reaxx, though it drops down through the table. They don't sell it in the United States due to patent issues with the Saw Stop version.
- yetihehe 6y ago
  > You’re out ~$150 if you trigger it. Small price to pay for keeping a finger. You can also trigger it if your wood is too wet. That was one of reasons given against using it everywhere.

by snazz 6y ago

roel_v 6y ago

Those videos show up in my Youtube feed the last few weeks too (although these saws have existed for many years now), but I still wonder - why do they always use hotdogs in the demo videos? Can't they find anyone who's willing to risk a finger, or is it something much more boring like OSHA rules or something?

throwaway0a5e 6y ago
>or is it something much more boring like OSHA rules or something? I think it's more like if you understand the tech well enough that you are willing to risk it you likely understand how not to stick your hand in a saw in the first place, don't see the value add and don't wind up working for these people. Also there's probably a pretty big social aspect of it. The guy willing to stick his hand in the saw for the demo video is gonna get shunned by most of the kind of people who want to work on tech like this.
jacquesm 6y ago
Technology can fail, so why risk it? I'd not trust my fingers to someone else's design either, no matter how good, though I'd be happy to have that system installed on every table saw. But we'll have to wait until the patent expires. Even table saw blades that are protected like that should still command healthy respect and anybody that wants to show off that capability is throwing the dice. It's a bit like driving into a wall at 50 Kph to prove that airbags work. Sure they do. But you may still get injured.
grumple 6y ago
There’s a video of the guy who makes them using his finger. There’s another on their website, search for sawstop. But as for others, tech can always fail so why risk it? Also it costs $100 each time you do it so it’s not like a ton of people want to waste the money.

Unklejoe 6y ago

> something moist like your finger I wonder how well this would work in a real life scenario. My dad does autobody work, and his hands are like dry, cracked stone. They probably have very high electrical resistance. I'd imagine a wood worker's hands to be similar.

jacquesm 6y ago
The first nick will conduct plenty due to the blood.
jagraff 6y ago
Once the blade started cutting through the skin and got to blood vessels, the resistance would go way down, so it would probably still work - just with a larger/deeper cut than more conductive hands.

Igelau 6y ago

How am I supposed to cut my hot dogs now?

DarkWiiPlayer 6y ago
Completely dry them first, cut them, then let them soak in water overnight. Can't guarantee they'll taste 100% the same, but you get around buying dedicated hot-dog cutting hardware.

wmeredith 6y ago

These saw brake systems aren’t on “modern table saws”. This system is branded and patented and only exists on Saw Stop table saws (no affiliation). If I recall correctly, the inventor took the tech to the big saw makers when it was first in invented and was turned away, because of some combination of he wanted too much money and they didn’t want the liability of marketing a “safe” table saw. So he started his own company. The tech is truly something incredible. It uses a disposable cartridge with a shotgun-sized charge to ram an aluminum matrix into the bottom of the spinning blade if it detects current (oily skin touching the blade closes the circuit). It stops it in thousandths of a second and your left with a nick instead of maimed. It ruins the blade and the cartridge. You’re out ~$150 if you trigger it. Small price to pay for keeping a finger.

snazz 6y ago
Huh! Thanks for the correction. I was under the impression that it was more widespread. I forget the brand of the table saw I used most recently, but I do know that it has that feature.
- speg 6y ago
  Saw Stop is the original one. Bosch does have their own version called Reaxx, though it drops down through the table. They don't sell it in the United States due to patent issues with the Saw Stop version.
yetihehe 6y ago
> You’re out ~$150 if you trigger it. Small price to pay for keeping a finger. You can also trigger it if your wood is too wet. That was one of reasons given against using it everywhere.