Dado blade on a Sawstop

We recently published a short demo on activating the Sawstop table saw using a Dado head.

Now we’ve go the longer, indepth video to show you – its worth watching in full.  Also, make sure you check out the full transcript below the video.

Activating the Sawstop safety system using a dado head

Dado blade on a Sawstop transcription

Well, good day. Welcome to Stu’s Shed. It’s going to be an interesting day today. We’ve been looking forward to doing this for quite a while. Now, we have all seen the sawstop in set-off on a blade. We’ve all seen how fast it goes; it’s a very spectacular sight But I’ve never seen it stop a dado blade on a sawstop. So that’s what I have for you today.

I must admit, I have a bit of trepidation. It’s an interesting thought, trying to stop that much metal that is spinning around. Not only that, but just the idea of trying to get it off the saw afterwards is going to be interesting, as well, because it’s as much as a single disc of steel using a 10-inch blade spinning around, which is quite a thump. But I want to know. I just don’t know what to expect with an 8-inch dado blade on a sawstop.

It is going to be something interesting.

Now, before we get started, a couple of things to go through. Firstly – and it’s recommended on the box and it makes perfect sense – the sort of dado blade that you should be using this for is one of these ones here, where there is a couple of outside blades. Obviously, it’s a non-alternating top bevel with one being the left and one being the right-hand side. And you have chipper blades in between. And something like this one, which has a couple of chippers on it is highly recommended.

If you get one of these other ones, such as I have here, where the chipper blades are an entire disk, it’s a hefty amount of steel to try and stop. Now, in saying that, the sawstop probably could bring it up short – well, it would jam onto there and lock on. It might take a little bit longer to stop, the damage to you might be a little bit more. The main thing, though, is the damage to the machine, trying to stop this much steel spinning – it has a fair chance of doing some damage.

Now, in saying that, it’s a safety mechanism. And when you have a car accident and your airbag goes off, you’re not so concerned about the fact that you’ve just blown your steering wheel apart with the airbag coming out of it. You’re more worried about the fact that the safety mechanism has actually worked and helped you.

And I daresay it would be the same here. If you were going to do a cut and you were going to do yourself some injury, better to bend the shaft on the saw, even if you have to replace that, than to suffer the injury.

Now we’re going to play around with this blade here. I actually have no plans to reuse this one again. We’re going to use it once or twice, just to see what it’s like. But I’m going to tell you what, the saw struggled to even get this thing up to speed; it’s that much steel when you pack in the two outside blades in all the spaces. So I just wanted to tell you that one, this is a blade not to use – probably a pretty good practice not to use it, anyway.

Now, the other sort of blade – I don’t even have one to show you – is a wobble blade. This is a dado blade that actually has deliberate runout, and a controllable amount of runout. So it oscillates from side to side to kind of cut the width – of the kerf widths – that you’re looking for.

But there are perfectly good examples of dado blades out there. This one here is just so cheap and nasty that I’m going to sacrifice it to the cause. I’m sure it’s not that cheap; it’s probably over $100 worth of dado blade. Even so, I’m keeping my primary dado blade, which is my other dado blade here, keeping that well and truly safe. Unless, of course, I don’t put myself in harm’s way, in which case, all bets are off.

Now, before we get started, I need to change the saw over. It currently has the break for the 10-inch blade and I need to change it over to a dado blade break. Now, removing the existing break is a very easy thing to do, especially when it hasn’t been jammed onto a blade already. Now, obviously, you already removed the insert and removed the guard. So down here, there is just a red knob. Just turn it 90 degrees clockwise, that pulls out.

And because this is a perfectly good break, I’m going to be careful, taking it off. And there we have it, that’s a 10-inch blade break, which is one that we have all seen, many times. Now, what I have here is the sawstop 8-inch dado cartridge. Now, that is a substantial bit of break, there. If I put it up against the other one, we’re talking a lot more – obviously, for a start, it actually has to reach further, because the 8-inch dado blade on a sawstop is going to be further away from the break, if you will, than the 10-inch.

But it also has a much larger contact area there,  the width of the blade. But again, it mounts exactly the same way. Let’s get this wound up. Push this on and then you’re ready to retain the lock that goes on. And a quarter turn, lock that on. Now, start stepping on the spaces. One more on. Okay and it’s all on, now.

I’m just going to drop it down to a cutting height. Obviously, the dado blade doesn’t cut full depth. You don’t need it to cut through the timber. What you want is to be able to cut your dado, or your rabbit  or your trench, or whatever you want to call it.

Now, for this view, I’m actually going to leave the insert off the saw. Now, obviously, that’s not an ideal way of operating the saw; you always want to operate with that insert in place. But I’m leaving it off because I actually want to get that extra camera view, looking down. All right, I’m almost set up and ready to go. There’s just one last thing I want to do.

Now, I have here, my human finger analogy. I went down to the supermarket, especially for this. And I have here, a couple of nice, fresh frankfurters. Now, as we’ve talked about in the fast, the saw actually puts a small charge into the blade and it detects how that charge dissipates. And if it’s going into something nice, big, salty, wet – like a human – that it picks up on that and that’s why the break activates.

And very simply, I am not going to put a piece of me, actually, in the line of fire. Now, a piece of sausage on the turn – or frankfurter on the turn – is not going to activate the saw, unless I am actually holding it, because that’s me actually making conductivity through myself and all my mess is going to be detected by the safety mechanism.

Now, one last thing that I’m going to do before we actually go on to the actual sawstop is, I have my other table saw set up here. And I have a dado blade set up on this, as well, at round about the same width as I have on the sawstop. This one obviously doesn’t have that extra safety protection of the sawstop mechanism.

So we’re going to do a cut, just as if I was going to do just any normal dado cut, with the sausage in the way. And I will just show you the sort of injury that you could actually sustain from a dado blade, in a normal situation. Now, when you’re standing at your saw and you’re going to do a dado blade cut, the dado blade, as I said before, is not at full height.

So you don’t have that visual clue of the saw, actually cutting through the timber, that you can actually see and see where that line is drawing and hopefully, notice that it’s actually drawing a bead on your body part. You just don’t have that point of reference.

And if you’re standing trying to guide a piece of timber through the saw, it would be very easy for you to just make that slight mistake and have a finger or a hand extended out and not realize that it’s in the line of fire, until the saw is actually coming out the other side. So that’s where we’re going to be holding our sausage, on the other side of this piece of timber, as I feed through the saw.

Now, you may think, “That just wouldn’t happen.” As you’re feeding the saw through, wouldn’t you feel a touch? Wouldn’t you feel the pain? But I can tell you, I can assure you, the speed at which you normally feed timber through a blade – and I went a little bit slower than I probably normally would – but by the time you’ve actually registered that you’ve started to cut yourself, it is – I can assure you, it’s absolutely too late.

Every single person who has ever done themselves an injury on a table saw will be able to tell you the same thing. By the time you have realized that you’re actually causing yourself an injury, the game is already over. Now, let me show you what you would actually see when you went down to the emergency department and presented yourself, afterward.

It’s surprising. It’s not torn, it’s not shredded like I was expecting. It’s a perfectly square-sided dado cut. And I have no doubt, after seeing that then, that if you did that to yourself, that’s what you will end up with. It’s almost more shocking, in a way, how perfect the cut is. Nature doesn’t build things in straight lines. And yet, there is a perfectly formed cavity.

It would almost be worse, seeing that wound, in some ways – I can imagine – than having something like you would expect. But my God, the damage that would cause, it’s phenomenal. Okay, let’s put this thing aside; it’s a bit freaky. There we go, we have our perfectly good dado cut from the dado blade. Now, I’m going to come across now, to this saw. And we’re going to do the same cut, this time, on a new finger analogy.

Right, so here we are, all set up to go. Now, we are actually going to drop the sausage in front, in this case, rather than behind, simply because I don’t have that insert in place. One way or the other, you still see what happens when the dado blade on a sawstop just touches the sausage, and therefore – through my contact – me. So I’m just checking: everything is set up, ready to go.

Wow. That was pretty impressive. I’m just looking, I can’t even see where that dado blade touched the sausage. It is in perfect condition. It’s spectacular, seeing the sawstop drop and set itself off, it really is. It always is. But my goodness, that’s a massive reaction. Every time you see that, it just blows your mind.

Last job I have, let’s try and get this puppy about. So let me just do that. I’m just going to bring the saw back up to full height. I just need to see how difficult it is going to be, to actually get that blade off there. I imagine it’s not going to be easy. But, you know, if that was me, instead of a sausage, then I would be looking at myself going, “Thank goodness.”

But, as I said, my heart is still racing a bit after that one. Whenever the sawstop goes off, it’s quite spectacular. In this case, that was almost more violent than I imagined. But the saw stopped, the sausage is safe and my fingers are safe. Okay, so far, so good, the lock-off. Now, it’s a matter of leveraging from the back and from the front to get the break and the blade off together. And there we go. And it’s beautifully embedded.

Interestingly enough, the minute our tieback was on, all the chippers are actually loose. They haven’t spun around or anything like that, so obviously, I had it up to the right amount of height that’s on the hammer. So they are loose. Now I have at least one chipper there that has absolutely blown a tooth off it, I can see that.

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