Mother Jones talks about Table Saws

[woodturner]

Here is a link to a kickback injury from someone using a SawStop saw:

Thanks for the link, good point about the overconfidence.

Testifying for plantiffs sueing manufacturers and trying to get new regulations or laws promoting your product are not enforcing a patent and will do little or nothing to protect it.

That's a good point, I agree.

It's my understanding he is trying to get a "generic" safety requirement imposed rather than specifically mandating SawStop. If he is actually trying to mandate SawStop specifically, I'm inclined to agree with you. I do think improved safety is a good goal, though, and if he is lobbying for safer saws, I see that as a different case. I think that is generally a good thing, and it says more about the other manufacturers if they are unwilling to develop a competing or better technology.

I just wish he didn't want so much money for it which has helped manufacturers decide not to use it. Mr. Gass has a right to do this the way he is, I just wish he'd decided to price it low and make it up on volume as manufacturers came on board.

It seems like a "chicken or egg" problem - he is likely losing money or barely profitable at the quoted $100 price, due to the low volume. So, he either has to take a loss on the risk quantities will increase, or he has to sell it at cost or slight profit to get it down to the $100 range. If he can get it mandated and get volume up significantly, though, then his costs should decrease a lot. Maybe if it were on every saw he could sell it for $20? No real basis for that number, just guesstimating based on manufacturing cost for similar products made in the tens of thousands.

In any event, it's a complex and difficult issue, with no clear solutions.

EVERONE, PLEASE be careful out there - I'd had to see more bloody pictures and read about other injuries.

[capncarl]

Getting away from all the conflict about air bags and moral issues of SS and its owner, why hasn't SS built a cheaper saw, or a retro-fit kit we could install on our own saw so we could all protect our digits with? My first guess without tearing one of the devices apart and putting the meter to it is.... it will not work on a direct drive saw with the cheap saw motor on the same conductor (shaft). Too much electrical interference. I don't really see how the device works anyway and what keeps it from randomly self destructing, what if you hit a wet spot? I would prefer using a stop device like a disk break caliper around the blade and not a throwaway unit.
capncarl

[woodturner]

I don't really see how the device works anyway and what keeps it from randomly self destructing, what if you hit a wet spot? I would prefer using a stop device like a disk break caliper around the blade and not a throwaway unit.
capncarl

If you hit a wet spot, it trips. Strangely, on their saws you can turn off the protection feature when cutting wet wood.

I don't think a brake caliper would work, it wouldn't stop the blade quickly enough to prevent injury. That's the technical challenge with protecting the saw user - how to stop the blade quickly enough to prevent injury. It takes a surprising amount of force to do that, and is probably the main reason others have not yet developed an alternative technology.

[cabinetman]

Some very good technology for saw safety comes with saws. It's that thing that was removed by the operator. It's called...
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A BLADE GUARD.

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[Stytooner]

Thanks, Mike.

[woodturner]

blade guards

Hey, maybe you can get CPSC to mandate your blade guards on all tablesaws .

No question that guards have their place and are good practice for cuts when they can be used. I have guards on all my saws and use them. They don't work in every situation, however, and that's where technologies such as SawStop can provide an additional margin of safety.

Perhaps the better answer is to advance beyond the 200 +/- year old technology of table saws to higher tech, safer technology. Doesn't seem like we are far away from cost effective laser technology that could replace a table saw, for example, and CNC routers are replacing table saws in many pro shops and are coming down in price to the almost affordable range for home shops. Any technology like that which does not require the operator's body parts to be near the cutting action seems to be inherently safer.

[Cochese]

Hey, maybe you can get CPSC to mandate your blade guards on all tablesaws .

No question that guards have their place and are good practice for cuts when they can be used. I have guards on all my saws and use them. They don't work in every situation, however, and that's where technologies such as SawStop can provide an additional margin of safety.

Perhaps the better answer is to advance beyond the 200 +/- year old technology of table saws to higher tech, safer technology. Doesn't seem like we are far away from cost effective laser technology that could replace a table saw, for example, and CNC routers are replacing table saws in many pro shops and are coming down in price to the almost affordable range for home shops. Any technology like that which does not require the operator's body parts to be near the cutting action seems to be inherently safer.

I don't see why table saws couldn't operate much like drum sanders do, with an adjustable overhead belt feeding the stock through at a steady rate with adjustable pressure. Wouldn't work for all cuts, but for sheet goods it would take the operator out of the equation.

[cabinetman]

I don't see why table saws couldn't operate much like drum sanders do, with an adjustable overhead belt feeding the stock through at a steady rate with adjustable pressure. Wouldn't work for all cuts, but for sheet goods it would take the operator out of the equation.

They have been in use for quite a long time. They're called power feeders. Works great on shapers and router tables too.

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[woodturner]

I don't see why table saws couldn't operate much like drum sanders do, with an adjustable overhead belt feeding the stock through at a steady rate with adjustable pressure. Wouldn't work for all cuts, but for sheet goods it would take the operator out of the equation.

Yes, sounds like a good idea, and a better solution than existing power feeders. I'm thinking the drive on a wide belt sander, though, a full width belt driving the work from the bottom and/or top.

The problem with existing power feeders and sheet goods is that the feeder wheels are too narrow and tend to skew the sheet. There are belt power feeders, but all the ones I have seen still use narrow belts rather than a full width belt like a sander.

[cabinetman]

I've used power feeders for many years and they are like any power tool. It's knowing how to use them and set them up properly.

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[JimD]

So maybe power feeders should be mandatory? (I am not serious)

I hope I am not arguing and just clarifying but the 5-8% Mr. Gass wants is not for equipment, it is a licensing fee. The manufacturer would pay Mr. Gass for the right to make a device that uses his patents. So on a 1000 saw, Mr. Gass would get at least $50 and would take no responsibility and would provide no hardware. There is an additional cost that we've been discussing as about $100 but I have since read would possibly be as low as $55 by some estimates for the device itself. So maybe the license fee plus the hardware would only be about $100 - or maybe it would be closer to $200. Probably we should be thinking of $100-200 since other changes to the saw might be required too.

If you want to believe Mr. Gass is being resonsable you have to get comfortable with him testifying in court that a person who used a table saw with no blade guard and with no rip fence was injured because he didn't have a SS on the saw. To me, the clear cause of the injury was the lack of use of the safety features that were proviced + operator error. If a SS is on the saw and there is a switch that allows you to turn if off when cutting wet wood, why couldn't an injured party still sue because the device was turned off and they got hurt? I don't think it is reasonable to argue that you can deliberately not use safety equipment provided with the tool and still say your injury was not your fault. If it is OK to do this, then either the SS has to have no switch (and destroy cartridges and blades if wet wood is encoutered) or there is no reduction in risk for the manufacturer.

Jim

[woodturner]

I don't think it is reasonable to argue that you can deliberately not use safety equipment provided with the tool and still say your injury was not your fault.

I suspect most if not all of us agree with this point. In my mind, the question is whether we can reasonably provide better protection - but the user still has to use it, and takes on the responsibility for injury if they don't use the provided safety features.

[vaking]

Getting away from all the conflict about air bags and moral issues of SS and its owner, why hasn't SS built a cheaper saw, or a retro-fit kit we could install on our own saw so we could all protect our digits with? My first guess without tearing one of the devices apart and putting the meter to it is.... it will not work on a direct drive saw with the cheap saw motor on the same conductor (shaft). Too much electrical interference. I don't really see how the device works anyway and what keeps it from randomly self destructing, what if you hit a wet spot? I would prefer using a stop device like a disk break caliper around the blade and not a throwaway unit.
capncarl

Technology behind Sawstop is not simple - it cannot be used as retrofit at all and I doubt it can be used on cheaper saws. In fact - there are no breaks and it does not really stop the blade. It is impossible to stop a blade spinning at 4000 rpm fast enough to save a hand that already touched that blade. The way Sawstop works - when a hand touches the blade the technology disengages the shaft on which the blade sits. This gives the blade ability to move freely. At the same time there is a metal bar jammed into saw teeth at a very specific point. This bar becomes the new center of rotation for a blade that is still spinning at 4000 rpm. With the center of rotation moved - the blade is being pulled under the table by its own momentum. The original article stated as a "BTW" that the blade is being retracted under the table when the mechanism stops the blade. In reality retracting the blade is the key here, the blade stops much later when the finger is already saved.

[BigguyZ]

I still want to see what happens when flesh is violently/ quickly drawn into the blade- like in a kickback situation.

Someone should do the hotdog test with whipping the hotdog into the blade at a fast rate...

[JimD]

Logically the depth of penetration is a function of the speed of approach to the blade. The amount of blade movement after detection is not variable, it stops as fast as it can be stopped, so the variable is how fast the flesh is moving into the blade's path. If you are moving faster, the penetration depth will be greater. Damage will still be limited by the SS, but possibly not such that stiches are not required.

Jim