Article on Skin sensing table saw

[Andy Brockway]

My company recently purchased one of these for the Carpentry Shop. They have now banned the use of non-safety table saws within the plant. The cartridge has an aluminum block shrouding the blade that is fired into the blade when activated. The torque of the motor forces the blade to withdraw into the table at the same time. This effectively ruins the blade and the cartridge needs to be replaced. Of course you can run with the safety circuit inactive, but why?

After all, what is the cost of a finger lost or having to be sewn back on? Besides the time you need it is when you least expect, most people try to work safely. This goes along with the other thread about working safely without safety glasses.

[KenWittlief]

Originally Posted by Andy Brockway

After all, what is the cost of a finger lost or having to be sewn back on? ...

good question. Is the company going to make the employee pay for the new blade and the $200 cartridge everytime they touch it and it triggers?

Seems reasonable, if you trip the sensor it was your fault, and it saved your finger, right?

BTW, does it really have a SAFE / UNSAFE switch ?

[Andy Brockway]

The company does pay for the new cartridge and blade, we currently have three in stock and hope we never need one due to an injury. We assume that the employee (associate is the company term) is trying to work safe.

We keep the spares because wet wood can trip the sensor. Also any conductive material such as lexan laminated with aluminum.

It can be run inactive depending on the startup from power off. I am going from memory of the demo we had but there is a main disconnect and an on/off switch. Possibly the alternate mode is when you have non seasoned lumber and do not want to chance tripping the blade.

[Alan Anderson]

Originally Posted by KenWittlief

Is the company going to make the employee pay for the new blade and the $200 cartridge everytime they touch it and it triggers?

The regular brake cartridge costs $69. The one to be used with a dado blade is only $89. I don't know where the $200 figure came from -- maybe it's for a three-pack?

BTW, does it really have a SAFE / UNSAFE switch ?

As mentioned before, it has a button to disable the brake actuator temporarily if you need to cut wet wood that might trip the system. The sensor circuit is still active, along with an indicator light that shows whether it would have triggered the brake.

I really don't understand your animosity toward this technology.

[KenWittlief]

Originally Posted by Alan Anderson

...I really don't understand your animosity toward this technology.

As I mentioned before, there are many ways to keep a persons fingers out of a spinning saw blade

better ways, that dont entail what amounts to jamming a monkey wrench into the system to stop it

the problem usually is that users disable the safety features, then they get hurt

so now, here we have this somewhat expensive new system, that the designer is trying to mandate into a government requirement.

That is the source of my animosity. Everything I have learned as an engineer says this whole system is not the way to go.

Also, everything I have read on the way this technology was developed says the inventor did not base his design on the real problem, because he did not work in the power tool industry, so how would he know if the leading cause of injury was equipment failure, blade failure, safety equipment being deliberately disabled by the user, or by the users supervisor, being distracted, not being able to see what you are doing...

Before you can design improvements to make a system better you must first know what the actual problems are, the root cause of failures and accidents. The designer of the MonkeyWrench Jammer was not in the loop, he did not have access, he did this on his own.

This system is a good example of what engineers call the two step, a bad design process:

1. Here is a problem (people get cut on saw blades)
2. Here is the solution (jam a hunk of metal in the blade!)

Why do people get hurt on sawblades? This product does nothing to address the root cause.

[John Gutmann]

Originally Posted by GaryV1188

How's this going to work if you're cutting metal?

would you be cutting metal with a metal blade?