HGTV-SawStop demo

[Jim O'Dell]

I just caught the very end of the show. Something Homes 2005. They showed the SawStop hotdog demo. It must have been the contractor saw because the whole saw jumped when the cartridge fired. (So did the host and hostess!!!) Too Cool! Jim

[Mark Singer]

I heard they may do a combined show with Emerill grilling the cut dogs....safe and tastey!

[Dave Wright #2]

Jumped? Interesting. I shot rough digicam video of the IWF cabinet saw demos. I didn't see any motion other than the sawblade stop and drop. Must have been one of the lighter contractor saws then. Let's see...the parts that drop probably weigh 20 pounds and drop an average of 2 inches at essentially the blade rim speed (100 mph). If the contractor saw weighs 15 times that maybe it would react by hopping up about 1/8" before gravity pulls it back down. Maybe the sudden motor stop had an effect too. The cabinet saw's greater weight would make it jump about half as high - maybe not noticeable to the casual bystanding digicam.

I still have no plans to test mine. Waiting for accident reports; more than 200 in use right now. What were those odds? 30K emergency room visits. Maybe 3M saws. That would be an average of one contact per 100 saws each year.

[Jim Dunn]

Seen the same show, wife informed me it would be on, and I too seen the saw jump. Just a nick in the hot dog. But would have liked to have seen the interior of the saw and blade. Course you can't buy a finger for any price so any damage would be cost effective.

[Dave Wright #2]

The interior of the HGTV saw might look a lot like the picture below except the casting at the bottom of the pitcure that joins the trunnions and collects dust would be different a design. The contractor version supposedly has the same cartridges and riving knife as the cabinet saw. It's mechanism rides on one linear bearing and a machined slot instead of two linear bearings like the cabinet saw. This picture was taken with the dust cover removed.

http://www.woodcentral.com/articles/images/484b.jpg

This is a blade that has been stopped:

http://www.woodcentral.com/vpix//pic173787.jpg

[George Summers]

.

I still have no plans to test mine. Waiting for accident reports; more than 200 in use right now. What were those odds? 30K emergency room visits. Maybe 3M saws. That would be an average of one contact per 100 saws each year.

Can't post a link, but over on The Oak there is currently a thread about the SawStop. One of the posters has one in a school shop environment that 'false fired'. Had to do with the wear strips under the pawls. You might be interested.

George

[Jeff Sudmeier]

Dave cool pictures! I didn't get to see the show, but hopefully I can catch it on re-runs, it would be interesting to see. 7

[Dave Wright #2]

Thanks George, after reading your post I went over to The Oak and checked it out. Evidently wear between the anti-kickback pawls and the insert can, through a chain of events, lead to the blade being pushed down into contact with the brake pawl. This leads to brake activation. This sounds like an easy item for SawStop to fix by design, and I imagine that SawStop will work with the saw owner to make up their costs.

I'm interested in the risk of false trips because I figure that their frequency will determine whether or not the blade brake is cost-effective. Below is how I see the numbers. The numbers are guesses or are rounded, but they probably are generally realistic.

3,000,000 saws in USA / 30,000 accidents per year = 1:100 chance of any given saw biting its owner in a typical year. Another way of stating this is that the average saw will draw blood once per 100 years.

$10,000 average accident cost / 100 years per saw to have an accident = $100 annual blade brake cost would be the "break even".

The above figures make me think that, in round terms, one misfire per year per saw would be acceptable. Sure, you could mount a fresh $250 dado set and ruin it on the first cut, but a more likely trip would be on a well-used $60 blade ($30 remaining value) for a total trip cost of around $100.