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Unread 08-09-2006, 13:42
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Alan Anderson Alan Anderson is offline
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Re: Article on Skin sensing table saw

Quote:
Originally Posted by KenWittlief
I dont know how proven it is...
A little research shows more than 50 people in the past two years who have had their digits saved, and none who have lost a finger, while using a SawStop table saw.

The manufacturers' complaint about false triggers on wet wood sounds like classic FUD. I know first-hand that a simple capacitive detector is discriminating enough by itself to tell the difference between flesh and damp plywood, and the system is additionally looking for a specific signature that indicates the blade's teeth are suddenly encountering a conductive object. You'd probably have to try cutting something like brine-soaked pine in order to force it into going off. According to the company, the system will trip if you feed it wood with greater than 40% internal moisture content -- which is something nobody should be doing. If you need to abuse the saw like that, the SawStop products have a temporary override feature that disables the brake actuator, but leaves the sensor and an indicator panel active so you can see if it would have triggered the brake on a given cut.

As for the proposal that you can prevent people from touching the blade, the same argument about subverting safety features applies. The SawStop technology is supposed to keep contact with the blade from doing major damage to a person when the usual safety procedures and equipment fail to work perfectly, whether by accident or intent. It's like an automobile's air bag, or a ground fault detecting circuit breaker.