Joe and all,

I manage a student shop in a college of architecture.

We've been running 2 of the first sawstops since Jan 05.

In the 18 months we've had the saws, the stopping mechanisms have
triggered 8 or 9 times. So basically ~$50/month insurance policy. All
but one have been user error: 1 chicken leg, 3 aluminum miter
gauge/x-cut fence, 2 gap distance (between blade and brake cartridge), 1
foil backed foam, 1 aluminum sheet (forgot bypass), 1 green treated
plywood. Hopefully we have fewer triggers as we and our our users learn
where we need to change our modus operandi. Sawstop has given us maybe
3 free brake cartridges for our trouble. They have diagnosed
"triggered" brake cartridges and called us with an explaination of what
probably caused the event (green treated, gap distance).

If conductive materials are embedded in a piece of wood, the sawstop
will not necessarily go off. In order for the brake to trigger, a
circuit must be completed, so unless the metal contacts both the blade
AND the saw table (or the operator) it won't go off. When I initially
tested the machine, I cut through dozens of nails and staples that were
clear of the table or my hand. the saw cut through them with no problem.

A couple months ago, the sawstop was demonstrated at a meeting of the
minnesota woodworkers guild. Unsatisfied with the usual hot dog test,
the demonstrator turned it up a notch. A 2' long summer sausage was
swung into the blade like a baseball bat. The blade got about 3/8" into
the sausage. I cannot imagine any circumstance in which a saw operator
could move into the blade as rapidly as that summer sausage.

I continue to be impressed with the quality of these machines, and look
forward to additional offerings from sawstop. Staven Gass recently
mentioned that the "other" saw manufacturers are settling sawstop
related lawsuits. I think it is only a matter of time until they
license the system or develop something of their own. Basically, I
think it will become too expensive for them not to improve the safety of
their offerings.

Good Luck
Kevin Groenke


Here are some comments I posted previously.


The SawStop cabinet saw is the best cabinet saw on the market.

Below are impressions I've previously posted regarding the 2 SawStop cabinet saws that we've had running since January.

original posts are here
http://groups.yahoo.com/group/archma...?query=sawstop

here is some other info
http://www.just4fun.org/woodworking/...views/sawstop/
http://www.woodweb.com/cgi-bin/forum...pl?read=386698
http://www.woodweb.com/cgi-bin/searc....cgi#reference


The only thing I would add is that customer service from the folks at SawStop has been great. We've had a couple more triggers, each time we've contacted SawStop to let them know what had happened. On the occasions of a false positive, or other technical problem, SawStop has sent replacement brakes and addressed any problem. Each of the "triggers" was technically our fault, we should have known that the SawStop would have been activated (blade/brake clearance, green treated ply, foil faced foam) and should have by-passed the mechanism. SawStop has taken back the spent brakes to analyze the data and has sent us more new brakes than we've deserved. As they should be, the saws are still like new.


INITIAL IMPRESSIONS
quality -

These machines seem are built much better than the unisaw that we bought 4 years ago(not saying much really). An extension table flatness problem has been mentioned, but our tables and rt wings are flat within .010". We never put on the left wings since we installed sliding tables, so I cannot speak to that issue. The trunnions, arbor shaft, bearings, and even the main table are beefier than comparable parts on a unisaw and a pm 66.
The polished handwheels are big and heavy with very nicely spinning cranks. Height & angle adjustment are smooth and easy (of course the machines are brand new, so they better be) .
I'd like a polished tabletop, and these are just ground, but that will make the first scratches less painful.
The machines are smoother and quieter than the last unisaw was when new.
A nickel sits on edge on the tabletop from start up through cutting 8/4 maple through shut down.
Initial indications are that these machines are well made. - time will tell.
design -
There is alot going on inside of these saws.
I like the linear (rather than arc) raising action, it seems much more intuitive even if more complicated.
A gas spring supports the arbor and assists blade raising.
The splitter/blade guard/riving knife is EXCELLENT - easy to change, easy to adjust, and wedded to blade height like it should be.
The blade guard itself is only about 1-1/4" wide and contoured to "hug" the blade- much less obtrusive than traditional guards.
We will likely ALWAYS use the riving knife and the overhead blade guard. I expect significantly fewer kickbacks as a result of the "invisible" riving knife.
The brake cartridge is not the easiest thing to change- but it will probably become easier as we do it.
The extension table is gloss black laminate. Black? Gloss? Can you say glare? We will probably start with sanding out the gloss, then get rid of the black if it is still too annoying. Sawstop took the color theme WAY too far here.
I look forward to seeing how the DC shroud works, but this is an arbor nutsucker waiting to happen.
What happens to the dust that gets past the DC shroud, how much dust will build up inside the cabinet, how hard will it be to get out?
If the DC shroud is effective, it should keep all of the other parts cleaner for smooth operation and less wear.
The large access door should allow enough access to service the saw, but it's under the extension table, so it still won't be easy.
The belt access door seems appropriate, not sure about the single splined belt - seems a bit light.
The bump switch is well located and a good size, after not much use, we should be able to easily shut off the saw, but it will be a while before we stop doing so inadvertently. The arbor/arbor nut wrenches are WAY TOO BIG, this will encourage overtightening and our ARBORS will be STRIPPED in no time. Are you reading this Steve?
The fence is a biesmeyer clone - faces are replaceable with "keyhole slots" - this is ok, but I don't really feel that they are flat/secure with no way to tighten them.
Rare earth magnets on the fence lever and dust shroud door are nice details, as is the "soft" fence handle.
The "power disconnect switch" is on the rear of the left side of the cabinet (beneath our sliding table) this is too hard to get to for routine blade changes etc...
In order to get inside the cabinet to change the brake/make adjustments, the throat opening is larger than a unisaw's. This is ok access-wise, but having less of a smooth, flat tabletop can be problematic.
The process to "by-pass" the sawstop mechanism must be done each time the saw started in by-pass.- a pain if we're cutting a bun of aluminum all day.
issues-
We occasionally used 8 1/4" thin kerf (3/64") blades for slotting and making scale lumber - sawstop requires 10" blades or 8" dadoes.
Hmmm, if we use the dado brake and an 8-1/4" blade...
We need to explain to 500 college students why and how the saws are different.
Gloss black extension table?
Separate arbor nut/washer invites droppage into dust collection and "washerless" re-installation. (We had welded a washer to a nut to eliminate this on unisaws)
I have to get rid of 2 old unisaws, 1 jet sliding table and 1 excalibur bladeguard.
The height of the back fence rail makes it impossible to mount a flush outfeed table (same as biesmeyer). I re-drilled and lowered, now 1 of the doors doesn't open past he rail, arggggh.

MORE IMPRESSIONS
(after a month or two of use)

These are very nice saws.
They are smooth, quiet, and basically a pleasure to use, definitely comparable+ to a PM66.
To date our students have had few problems making the switch from the unisaws.
The riving knife is great!: easy to change, never in the way and effectively keeps stock going in a straight line.
I sanded the gloss off of the extension tables and they are ok now.
After 15-20 brake cartridge changes it is pretty second nature (this is just an issue of learning where the "locating pins" are).
Arbor nuts/washers drop directly into the hose attached to the "dust shroud" we have enough suction to move the nuts to the most inaccessible part of the DC pipe. I suppose it's time for an access port.
We LOVE the paddle switch, a machine has never been so easy to shut off.
The "power disconnect switch" however is on the bottom back corner of the left side of the cabinet and is a pain to get to with the sliding table attached to the saw, oh well.

Now that SawStops are in service, I suspect it won't be long before Delta/Jet/Grizzly get sued (and lose) because they failed to provide such a system. Perhaps they will be beating a path to SawStop for licensing sooner rather than later. Let the market decide I suppose, should be interesting to watch.

THE TEST:
SawStop provided us with a demo cartridge and we tested the SawStop on Thursday, January 13th.

I cut a variety of materials such as: wood, plywood, melamine, acrylic, mdf. etc. I enabled the bypass and cut aluminum, green treated and stapled pine. When in bypass mode you will get a code in flashing lights indicating whether the SawStop would have triggered. The lights indicated that the SawStop WOULD NOT have been triggered by cutting the green treated or the stapled pine, so I proceeded to cut them with the SawStop on.

I then got out the drumsticks and cut one in bypass mode. It's amazing how easy it is to cut through a drumstick, pretty gory and except for the lack of blood, not unlike a shop accident. I've always thought of doing this during shop orientations, but decided that it could encourage sophomoric actions (the last thing they need is encouragement).

I'd been asked by some rec.woodworkers to push the stock rapidly into the blade in order to get an idea how much damage would be done in the case of a slip or similar accident.

So to test the SawStop I jammed the drumstick into the blade nearly as fast is I could, the blade promptly disappeared and with virtually no resistance I proceeded to IMPALE the chicken leg onto the riving knife (oh the shame).

RESULTS:
SawStop works: the blade definitely stopped and definitely dropped (observers indicated that this happened too fast to discern). Since the drumstick was impaled on the riving knife, I have NO IDEA, how much damage the drumstick sustained from the blade before it's encounter with the riving knife. As you can imagine this was a little embarrassing. Here we've spent $6000 on saws that "save fingers", and I've got a chicken leg skewered by a chunk of steel, not so impressive.

Coincidentally, the SawStop went off again the first time we tilted the blade as we had neglected to provide adequate clearance for the aluminum fence on the sliding table. DOH!!! Again observers were dumbfounded. Results: a tiny nick on the crosscutting fence.

I was expecting a significant jolt/vibration/lurch of the saw when the SawStop was triggered, but aside from a solid THUD and the "disappearance" of blade, there are little dramatics.


--



Joe Bemier wrote:
I was at the yard where I get most of my pine yesterday and I
overheard a conversation about Saw Stop. One of the guys was saying
that the Saw Stop safety mechanism will sometimes engage when no
hand/finger/whatever touched the blade.
Any of you guys have experience with Saw Stop?

Thanks,
J