I recently met with a new owner of the SawStop, and took them through some of the specifics of the machine, including some of the basics of safe operation of a tablesaw. As they were an experienced operator, the focus was certainly around the brake mechanism.
Six months later, and I get a call. Turns out the SawStop mechanism got tested for real. Scared the bejesus out of him – not only when it activated, but more fundamentally, that it happened at all. So we are going to have another session, and this time running through the A, B, Cs of tablesaw use.
Had my own experience last weekend. Not of the SawStop mechanism, but a reminder of basic safe operation.
I try to ensure that I am not standing directly in line with the blade when it is cutting. That isn’t always possible, but it is a good practice, and this time was no exception. I was standing to one side while ripping a piece of timber, and a piece of the offcut splintered from an unknown internal fault in the timber. It got spat out by the blade, and sailed right past my ear. Close enough for me to hear it pass by. Close enough that I felt it brush the ear.
Reinforces why I like standing to one side while cutting! Even if it had hit, it is unlikely to have done any damage, but it is a good reinforcement why we practice safe use. And why eye protection is mandatory.
I finished off the cut – nothing wrong there, so the technique was fine. It really came down to a weakness in the timber.
As much as I was out of the line of fire, it was a full-depth cut. And while having the riving knife fitted helps protect against kickback, having the full dust guard fitted when it was appropriate for it to be used would have prevented this happening at all, at least as far as having a small missile launched in my general direction goes.
Filed under: Manufactures and Suppliers, Safety, Techniques | Tagged: Kickback, Safety, Tablesaw |
Stu's Shed 
Some years ago I attended the wood machining course at Lidcombe TAFE. Of all the safety methods hammered in to us the most important was that in cutting anything except man made materials the rip fence must not go past the gullet of the first tooth to come into contact with the workpiece. I notice Sawstop for all its emphasis on safety does not allow the user to do this. This appears to be a common fault with US saws yet on most European saws I have seen a sliding rip fence is standard.
Gary, you are correct in that the fence should not support the piece past a certain point on the blade but the solution is a simple one. My saw has a full length fence as well and when I cross cut I always clamp a short piece of 3/4″ stock to the fence so that it stops my workpiece short of touching the fence…. you weren’t shown this by your instructor? I guess that’s owing to a growing tendency to rely on technological solutions rather than logical ones.
I think what is being discussed are a couple of different things.
For crosscutting, you definitely do not want the workpiece in contact with the fence when it is being cut by the blade. It must (only) be supported by the mitre gauge.
For ripping, I disagree about the workpiece not being supported by the fence throughout the cut. If there is a point that the workpiece is unsupported/only in contact with the blade (and not just the front edge, but the entire width of blade), then there is every opportunity for the workpiece to be twisted slightly offline, so the back of the blade takes a deeper cut, and thereby throws the workpiece at you.
I would not use a tablesaw without a full-length fence for that reason (unless the workpiece is supported in some other manner, such as on a sliding table). If it is a sliding table, then this falls into the crosscutting category, where the offcut can become trapped between fence and blade, and has every likelihood of twisting into the blade path.
To prevent the rear of the blade recutting the timber, I run my fence with a slight toe-out of a mm or so. The blade then only cuts the workpiece on the front teeth, and the rear teeth do not make any contact at all. This also means the body of the blade does not contact the workpiece, as the TCT teeth are slightly wider (cutting a wider kerf) than the thickness of the meat of the blade.
David
A small amount of common sense offers the solution you have suggested but I don’t have any desire to have to modify a tool that I outlayed some thousand of dollars.
I do note Stuarts solution in having a small toe out which many people apply even if they are using a fence that slides in two directions. I might add that Altendorf do not share Stuart’s view and the last time I looked at their instruction video they took the same view as my TAFE instructors.
Gary..
But to clarify, Altendorf machines are all (from what I can tell) based around a sliding table, and the workpiece is slid past the blade on the left hand side, with the fence on the right of the blade.
The sliding table provides the positive control over the workpiece.
In that circumstance, I would certainly agree – as it would otherwise lead to a situation where an uncontrolled offcut is captive between blade and fence.
Is there any example where the fence stops short, where a sliding table is not used? That is the situation I am referring to, where a full length fence is to my mind, mandatory.
It will be interesting to see when SawStop’s sliding table is available, whether it comes with a replacement, short fence. That would be sensible.
Altendorf are the originators of the sliding table but in ripping pieces under about 400mm in width the sliding table is not normally used (subject to length) only the right side of the table. You ask is the any examples od of a fence stops short of a non sliding table machine. I have a Luna (Swedish) machine that I purchased some 30 plus years ago whose fence slides in two directions.
Gary