What's new
What's new
By:
Advanced search…

Just saw a VERY interesting safety device

4

440roadrunner

Hot Rolled
Joined
Jun 4, 2006
Location
N Idaho
I realize that there's no substitute for being careful, but......I was watching "This old house" just now, and was a demo of a very interesting safety for a table saw. There's a sensor that detects moisture/conductivity from a finger. Using a hotdog, it was shown that an electronic brake device stops the blade and slams it down into the saw. It ruins the blade, and part of the mechanism, which you must then buy.

So much for sawing green lumber in the rain.

I'm not sure if this is it or not--I don't remember hearing a brand name

http://www.taunton.com/finehomebuilding/how-to/articles/sawstop-revisited.aspx
 
If you have ever tried to safeguard something like a wood cutting radial arm saw you see the $$$ well spent in liability. We talk about operators getting their hand too close to a 100 FPM endmill, drill, etc. while woodworking is generally 3-10,000 feet per minute. You can't get away from an industrial woodworking machine... best recourse is not be there in the first place. I'd rather buy a machine part than pay some employee mucho $$$$ for cutting off an appendage.
 
I have seen that demo, and in the demo it worked sorta ok..
but did you notice how Slooow they were feeding that hot dog into the blade?
 
"This old house" get paid for those demos ( I think Bob Villa used to sell Bobcad back in the 80's). If it can detect moisture from a finger will the saw work on a foggy day?
 
Recently, at my grandson's college, I'd seen table saws equipped with a similar device. . The blade was enegized with an electric current, and when touched by a body part, sensed the differentiation in the electrical potential, which enegized a brake of some kind in milliseconds. It must be some brake, because I was told the cost of tripping the device was about$75 in parts, plus the cost of the blade. If I remember, the brand was Saw-Stop, or Stop-Saw.
Paul
 
The device is neat, but-
How do you verify function of the device without triggering it? Boston's question applies here. If you can't verify correct operation under the conditions you are working in, you had better not trust it to work. If you accidently stick your finger in the saw, you may be pleasantly surprised by correct function-or not.

Stu Miller
 
That's a really impressive demo. I was wondering why they couldn't use an electromagnetic clutch/brake, but I doubt that could stop the blade in 5 milliseconds, like they're doing with their spring-loaded deadman's switch.

If it can detect moisture from a finger will the saw work on a foggy day?
Click to expand...
If you look at the oscilloscope, they're detecting the change in capacitance when you ground the blade.
 
The device has been around for a while, and had, so far as I can tell, next to zero market penetration.

One reason is that several leading causes of injury with table saws don't involve touching the blade. (Think kickback, think debris in your eyes.)

I don't recall ever hearing of anybody who cut themselves by touching the blade (it's about as obvious a hazard as there can be!), but being brained by kickback is a real thing - I witnessed a near miss that put a big dent in a steel wall in Jr. Hi School.
 
Yes, unverifiable, as it ruins the stop and the blade every time.

Wood water content has been a question for me also.

And, there is always the "it's safe, I don't need to pay attention" deal....
 
The device has been around for a while, and had, so far as I can tell, next to zero market penetration.
Click to expand...
Invented in 2001, click here for info. About as unpopular as a fart in church, perhaps because of the way the inventor petitioned the CPSC to mandate SawStop on all table saws, not just his brand.

Thank God they lost or we'd all be paying $2000 more for every table saw purchased :eek:

------------------
Barry Milton
 
I know there is no price on your finger, etc, etc, etc.

BUT, if the thing CAN "false", which I have heard alleged, rightly or wrongly, it will cost you, IIRC, about $130 plus a blade. And the time to disentangle the bits and replace everything.

Small cost if it allows you to keep your hand, certainly. But one dickens of a nuisance if it can "false".

And, YES, it has been discussed to death here and elsewhere.
 
The magazine article I read on this device was that it is electrical... not so much a moisture sensing deal. I don't recall the details, but it senses change in milliohms resistance somehow.... I have never seen one in person.
 
This does nothing to prevent kick backs. Believe
me one good kick back can be life changing.
Click to expand...
Would that have anything to do with table saws being just under waist level???

Thankfully the only wood working I do is with a match and a bag of marshmellows. Woodcutting tools always scared the crap out of me.
 
You must log in or register to reply here.

Similar threads

goldenfab
The Goldenfab Story
2 3 4
Replies
66
Views
31K
CBlair
C
R
Need help with a VERY Small CNC shop: Carpet, HVAC issues
Replies
3
Views
2K
implmex
I
Milacron
Sawstop table saw comments
2 3
Replies
52
Views
13K
stephen thomas
S
Richard King
Scraping a tapered gib
Replies
17
Views
15K
JeffMoss1
J
S
Using a 0.006" slitting saw on an extremely hard and tough metal. yea or nay?
2 3
Replies
42
Views
12K
dynosor
D








 

ABOUT PRACTICAL MACHINIST

With more than 10.6 million unique visitors over the last year, Practical Machinist is the most visited site for metalworking professionals. Practical Machinist is the easiest way to learn new techniques, get answers quickly and discuss common challenges with your peers. Register for the world’s largest manufacturing technology forum for free today to stay in the know.

Learn more about us.

STAY CONNECTED

Facebook Instagram YouTube LinkedIn Pinterest Twitter Tiktok

Register Become a forum member. Register today.

Sign Up Sign up for our e-newsletter.

© 2024 Copyright Practicalmachinist.com. All Rights reserved.

Back
Top