Do you remember the first time you hammered your thumb? I do. It hurt like heck, and it was a long time before normal pink flesh color returned to it, and the nail wasn’t threatening to fall off. At least I still had the thumb, though.
What is the value of a human finger, though?
When I graduated from hand tools to power tools, the adjustment was very gradual. A power drill I used to drive screws or drill holes seemed pretty easy and pretty benign. I could handle this; I recall thinking.
But my father’s table saw was a different matter and a very different animal. It was loud, the blade was exposed, and that spinning blade was scary. Then, there was the incident in 8th-grade shop class in middle school where the teacher lost half an index finger and an inch of his middle finger, and where one student barfed and the rest of us watched on in horror as blood was spraying everywhere.
Power tools are dangerous, and care needs to be taken with their use. Safer glasses, work gloves, and maybe even a face shield are essential items in your shop inventory. Butchers wear metal mesh gloves, as do fishmongers, when breaking down their catch. Safety first is the rule in so many workplaces, and it needs to be taken seriously.
Enter Sawstop for the woodworker’s home workshop. We’ve written about them in the past, and you’ll find a couple of pieces here and here. We’ll continue on about Sawstop and shop safety in this article.
What is Sawstop?
Table saws, as we’ve said, are the beast in the room. Powerful cutting machines, they will break down a plywood sheet in just a couple of passes, whether ripping or cutting, to dimension and perform woodworking tasks that other power tools just can’t do.
Scraps of wood are used to push workpieces through the blade to keep hands at a distance from that scary blade. The addition of riving knives keeps the kerf open as the workpiece is pushed through the cut and, in the process, makes kickbacks far less likely. Riving knives are required now on all new table saw models and have been for a while now.
While these steps do reduce the chances of a skin to blade injury, they do not eliminate the chances of losing a digit. Again, we ask, what is the value of a human finger, your finger?
One of the leading innovators in the development of shop safety and the prevention of serious skin-to-blade injuries in the workshop is SawStop. However, Sawstop has gone well beyond riving knives which are designed mostly to prevent kickback and damage to your face.
Sawstop manufactures table, cabinet, and other power saws. Their power saws are viewed as the safety standard against all other power saws are measured. Their saws include:
- Models for jobsites – these are portable saws, easily moveable from site to site as needed;
- Models for contractors – powerful, sturdy, and with cast iron tabletops; and,
- Professional woodworking shop cabinet models – two different power standards, an excellent dust collection system.
The latter is Sawstop’s best-selling model. These saws are also a bit pricey, ranging from around $1600 up to $4715 (before accessories), depending on the model and motor hp rating.
Although each of these saw models has its own strengths and proper place in the woodworking industry, there is one feature they all share in common: the most advanced safety features in power saws today.
What Is Sawstop’s Patented Safety Feature?
Skin to blade is the contact we want to avoid when using power saws. While it is not possible to protect your skin fully, the safety feature developed by Sawstop brings you as close to full protection as possible.
Its patented safety features work as follows:
- The blade in a Sawstop power saw carries an electrical signal that senses contact with human skin.
- When contact with human skin is sensed, that signal changes. The change in that signal activates the safety feature.
- The housing in which the blade sits includes a brake, and the change in signal releases the brake into the path of the blade and stops its spinning almost immediately.
- The saw is also shut down at the same time.
- The blade then drops down into the housing and below the saw’s table, thus removing it from further access and harm.
- When we say almost immediately, all of this happens within 5 milliseconds.
- The blade and brake cartridge can then be removed from the housing and replaced within just a couple of minutes. The saw can return to active use once you have attended to the injury to your hand or arm.
The advancement in safety features introduced by Sawstop has reached an almost techno-future status. The safety mechanism is truly amazing, and the brake activation is almost instantaneous; we suspect many fingers, thumbs, and forearms have been saved from serious injury as a consequence. Testimonials on the Sawstop website attest to this.
You probably noticed the blade and brake cartridge mentioned, and yes, this means you will want to keep a spare handy and replace it with another spare when it has replaced one in the housing. They run between $105 – $115, and yes, a bit pricey, but again we ask, what is the value of your finger?
We mentioned in a previous piece the speed at which our brains process input, but it’s worth mentioning here again. The human brain processes knowledge in milliseconds, which means that just as your brain is processing skin-to-blade contact, the blade has already stopped and has dropped down into its housing and away from the tabletop where it could have continued to cause harm.
We think that’s pretty amazing.
Beyond this safety feature, Sawstop power saws also include a riving knife, as is now required on all table saws. The riving knife keeps the kerf open as the workpiece is pushed through the blade, thus preventing kickback to your upper body, face, and head.
You might be wondering if a special blade is required with Sawstop cabinet table saws. It’s a fair question. After all, the safety system works as it does when human skin comes in contact with the blade, and you might assume the blade has some special feature that triggers the safety response of the Sawstop system.
The fact of the matter is, though, that there is no particular requirement for the blades used on their saws. Any standard blades will work within the safety system with just a few considerations:
Non-conductive blades need to be avoided. This also includes those with non-conductive blade teeth, such as diamond blades. These blade types will interfere with sensing contact with human skin, and the electrical signal that triggers the safety response will not be applied.
Additionally, steel blades with a coating of lacquer on the teeth or other coating might slow down the speed at which contact with human skin is sensed.
Most blade manufacturers, though, do not coat the teeth of blades, making them safe to use with Sawstop saws. Blades are mostly accurate to their stated diameter, too, and are safe to use with these saws.
The Sawstop safety feature is designed to the specs of a 10” blade and with a kerf of 3/32 “ to 3/16 “, but you should avoid using blades with a thinner kerf since they might not be able to take the pressure applied by the braking system when it is activated by skin to blade contact.
By the way, you are not limited to standard 10” blades with your Sawstop. Dado blades will also work well within the Sawstop safety feature as long as you follow the same caveats we have outlined for you above. Non-conductive blades, blades with coated teeth, and diamond blades should be avoided as they will hamper the signal that will activate the braking and power-down system within the Sawstop safety feature.
Again, we want to emphasize that blades with coating on the teeth, like lacquer, should not be used. They will inhibit the detection of skin-to-blade contact and slow down the activation of the braking system and the power-off feature of the safety configuration. If the teeth are coating-free, though, you should be fine.
How Safe is A Sawstop?
This is a fair question, and it just so happens we found a video made by a real professional woodworker. While we could have written about the science of what happens when a blade comes in contact with human skin and broken down the description of what happens to each part of the safety system, it probably would have put you to sleep.
However, in this video, not only is all of that explained, there is actual footage at regular speed and in slow motion to show you what happens. He even breaks down the science of the feature as well. He uses a hot dog to demonstrate the system in action.
It really is worth watching. The video is very well done, the videographer is very knowledgeable, and he’s clear in his explanations. The statistics kind of staggered us a bit – 67,000 table saw injuries in the US each year. Be sure to take a look and make sure you are not one of the 67,000.
For additional information about Sawstop table saws, we found another video that will demonstrate how to change and adjust the blade in a Sawstop saw. It, too, is worth a watch.
We want to point out that neither of these videos is from Sawstop itself, which is why we chose them for this article. They were made by actual professional woodworkers with real-world experience using their Sawstop table saw. Each of the saws, too, is professional grade, just to make the even finer point for you.
We are fans of Sawstop saws. We will tell you we don’t yet have one in our woodworking shop yet, but we do plan to someday. In the meantime, we stay current with our knowledge of the Sawstop safety system for all the obvious reasons.
Our fingers, hands, and forearms are important to us, and we’d like to keep them. We follow all safety protocols for a woodworking shop with power tools that could cause us to suffer injuries – safety goggles, safety face masks, work gloves, and keeping our power saws soft, slow, and smooth wins the day in the workshop.