For some of the various reasons stated by other posters, I replaced my Delta saw with a slider.
For some of the various reasons stated by other posters, I replaced my Delta saw with a slider.
Pretty interesting numbers already. I really like to find out the answer to the following two:
- Has anybody (not just SMC members) seen/heard a kickback while operating a table saw (any kind) WITH a properly installed/aligned riving knife?
- Has anybody heard a Sawstop fail to fire when it should i.e. serious injury resulting from contact with blade? I know this possibility is non-zero but would like to know if there has been any so far.
Does anybody know how one can get any source of data for the above two questions?
I may have to change my answer. I voted "non-SS owner: no injuries" because I was thinking about blade injuries. I have experienced 2 severe kickbacks, both when I used a $99 Ryobi saw without the splitter or pawls. The sides flexed and the fence folded in half on the second one. I have had no kickbacks while using a splitter.
It has been awhile but I have experienced kickbacks. A couple of them could have been serious had I been standing somewhere other than where I was. However, the question included a riving knife caveat. I was not using a riving knife; in other words, I was not employing all appropriate safety precautions. I have had no kickbacks while using my upper saw guard which includes a riving knife with pawls.Quote:
Originally Posted by mreza Salav
The data that I have seen on these incidents has all come from what I considered a biased source; the absence of false firing data and data showing the effectiveness of a simple riving knife is to be expected.
It's hard to know how representative the poll numbers might be, but taken at face value there's a disturbingly high level of false firings for a technology that is being pushed as the basis for a national standard. Presuming that these saws need a new cartridge every time that'd suggest it'd be pretty close to a license to print money...
ian
It's interesting how different people see different things in statistics. I was struck by the high rate of injuries in the non-sawstop group. As of the statistics right now, approximately 17% of the non-sawstop owners have had an injury from their saws (18 injuries, 88 non-injuries for a total of 106 reporting. 18/106 is about 17%). In my opinion, that's a pretty high injury rate.Quote:
Originally Posted by ian maybury
Note that as of now, there were no injuries reported from the SawStop group, even though there were reports of false firings. While a false firing has a cost, injury also has a cost, sometimes a high cost.
Mike
Although it wasn't intended as such it looks to becoming a referendum on the SS. Non blade injuries should at least be segregated as SS has no real advantage there. The percentage of kickback to blade injuries is probably relevant however. Dave
Case in point: the scar on my forehead from a kickback injury on my sawstop... which of course was my fault. I'm currently the only person who voted with an injury on my SS.
Sorry to pile on here, but while I do enjoy this conversation, I also don't think you can use this data for anything.
You would need to normalize this data based on the number of SS and non-SS saws in use today. Obviously you're going to have higher numbers for all stats in the non-ss categories because there are more far more non-ss tablesaws in use than SS tablesaws. You'd need some kind of per capita measure.
Or maybe you would only survey people who have bought a brand new saw since SS hit the market. Likewise, some saws have riving knives, blade guards, anti-kickback pawls, etc, and others don't. You can't compare a ryobi benchtop saw to a euro slider or SS, etc.
But like I said, interesting conversation!
Quote:
Originally Posted by David Kumm
It's a simple poll, with kickbacks included intentionally. It's not a comparison of SS technology.Quote:
Originally Posted by Peter Aeschliman
What would I use the data for, Peter? It's just a poll. Too many people are trying to make it more than it is for the purposes of explaining why it's not.
How'd the kickback happen anyway, Peter? I think I remember you posting about that.
I think the riving knife will get rid of some of the major board launching back at the user type situations, but it's still possible with smaller pieces to get them jammed up before the knife.
There are several interpretations of this observation, all, some or none of which may contribute.Quote:
Originally Posted by Mike Henderson
1. Sawstop technology is relatively new, so SS owners are by inherently limited as to the years running the saws. However, I'm sure there are users who have used their conventional saws for decades longer than SS users possibly could.
2. Sawstop saws are expensive compared to the wide population of saws available for sale. While I think the magnitude of this premium is vastly overstated, and while the SS is by all accounts an excellent saw even forgetting about the braking, a buyer who opts to pay this premium is likely to be doing so for safety reasons. Hence, there is self-selection for safety consciousness among SS users.
3. Related to 2. above, someone willing to pay for a premium saw is more likely to be an experienced or committed woodworker than someone who is satisfied with a less expensive machine that is presumably at least somewhat less well made. It would be interesting to see what accident rates look like in, for instance, buyers of new General 650s.
4. There is probably a correlation between Sawstop ownership and level of income. The latter is correlated to education level.
5. Sawstop owners may be less inclined to report injuries. I doubt this effect could be very strong in an essentially anonymous survey, but as someone trained as a psychologist, I know this much: people are funny.
A rigorous study would select a sample of users with varying levels experience and saws, and conduct a longitudinal survey of accident rates. No, I didn't expect this survey to do so. But I am sure someone HAS done it.
Not trying to dis your thread! But as an analyst by trade, I'm uncomfortable with peoples' attempts to infer injury rates from this data. This poll doesn't provide the data one needs to properly do so, even for rough purposes.Quote:
Originally Posted by John Coloccia
I should have said "I also don't think you can use this data to draw any conclusions." Obviously none of us are going to DO anything with this poll data, but it shouldn't have any influence on one's perception of the value of the safety mechanism either way.
Assuming you don't have issues with blood and gore, have a look at the thread I created. You posted in another thread that you had a guy come into your store high on pain meds with a bloody head... that could've been me, except my doctor just told me to take Advil!Quote:
Originally Posted by John Coloccia
http://www.sawmillcreek.org/showthre...!!)&highlight=
My intent was to point out that anyone can find something that will support their preconceived notions in any set of statistical data.Quote:
Originally Posted by Kelly Colin Mark
Because this reporting is self selected, it has little value for decision making.
Mike
Ahhhh. Somebody to geek out with :)Quote:
Originally Posted by Kelly Colin Mark
Yeah. John wanted this poll to just BE this poll. It is what it is, and I respect that.
So ... ignore me, John !
I'd figure the "safety conscious" would likely be offset by those who had a hit, or a near miss, or heard about a buddy who lost his finger on a TS.
[In one way, they COULD actually be less safe TS users than the average, coming to a SS /after/ an injury or near-injury.]
I'd call those a wash. I might even say that the truly safety conscious are -- consciously or unconsciously -- more aware of "risk compensation," and don't need no stinking badges, or flesh sensing technology, or blade guards.
[Risk compensation indicates that ... when you WEAR a helmet ... you might ride in a more inherently risky manner, assuming you're safer than you really are.]
Okay. Maybe riving knives, though ;)
Back to you, Doc !
Also, let's face it ....
It's a self-selecting sample, by definition.
What you'll see most -- quite likely -- is the same passionate folks on both sides of the SS debate chiming in -- an inherent limitation in passive polling, vs. actively phoning and polling TS owners, until you get an adequate sample size.
:)
I still think it's a cool poll. I just take it FWIW.