Insert plates

A day later than I intended, but I suppose that happens.
 
First things first, here are the insert plates.
 
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I’ve got one turned over, and you can see the detail that’s gone into making them. The white part in the center is where a slot has already been made so that the saw doesn’t catch on the plate when it’s in the table. If the slot wasn’t there, the saw blade would bind on start up and break the belt. Or worse, damage the motor. Also, because the relief is already there, I don’t have to start out with a smaller blade to avoid breaking something. Nice touch.
 
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Here you can see the differences between the stock (yellow) insert and the new ones. Much thicker, as it’s not metal. That’s why the relief is needed to clear the blade. Here’s a little more detail of the underside.
 
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Before I show you how I installed it, let me go over again why I got them. The theory is, that when you don’t have anything behind or supporting a piece of wood (especially plywood), you get tearout – when the cut looks fuzzy or it looks like pieces have splintered away. That’s why some of the projects I’ve done have a ragged looking edge – some of the top layer of ply has splintered off at the cut, leaving behind the darker layer underneath. It doesn’t make for a good look, and most of what you see in my pictures was done by my circular saw. I have some left over hardboard that I’m planning on making a zero clearance insert for that before I use it again. A zero clearance insert also supports small pieces from falling into the saw interior. This was a big reason why I hadn’t been able to use my dado stack yet. A third reason is to reduce uncontrollable dust. With the insert on, you get much more of the dust go where it’s supposed to – out the dust port and not all over the top of the table and into your lungs.
 
Now, on to the process: The first step was to remove the original yellow insert, which you have already seen a picture of. Next, I raise the blade up and remove the riving knife and guard.
 
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Now, I must pause and explain a little bit about the difference between a riving knife and a splitter, and the important safety aspect all of this plays. The riving knife is the hunk of metal you see right behind the saw blade. This prevents the cut material from closing back up around the blade and producing kickback. Kickback is very dangerous, and can bruise, break and kill. What also helps prevent kickback are the little pieces of metal with teeth, called pawls. They grab the wood and keep it from reversing direction. The guard also gives a visual representation of where your hand should never go. I doubt it would do much if the blade ever came apart, but I try not to think about that. Some guards also have a dust collection port, something I may look into if I start cutting in the shop in any capacity.
 
Now, there’s one big difference between a riving knife and a splitter: a riving knife is directly connected to the saw’s travel. It tilts, the knife tilts. It lowers, the knife lowers. A splitter does not. It is either directly perpendicular to the table top or it travels with the blade guard. It’s an inferior setup, but not a horrid one. I’d rather have a splitter than nothing at all. Obviously, with a non-through cut (one where the blade does not go through the top of the piece, like a dado or a kerf), neither is used.
 
Now that the knife/guard assembly is removed, the blade gets lowered all the way down to receive the new insert.
 
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At this point, I reached up into the saw and made sure the blade did not bind on the insert. Again, this is a bad thing. You’ll note that the saw was unplugged while I did this. Saw + power + hands = hospital.
 
After making sure it wouldn’t bind, I attached a sacrificial board to where the blade would break the surface. I did this to help hold down the insert, and reduce any tearout.
 
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I fired it up, and slowly went from full retraction to full extension, and shut it down and retracted the blade again.
 
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At this point I noticed the huge mess I was making in the shop. So, after dinner the saw got wheeled outside. Good news: no more mess in shop. Bad news: the mosquitoes had a buffet. While I had the knife assembly off, I decided to try out the dado stack and make an insert for that.
 
A dado cut is a wider than normal cut that does not cut through both sides of the wood, but makes a channel. It’s as wide as you need it to be, but generally as wide as a piece of wood you’re going to use for a joint. The dado set I bought has two outside blades, and multiple chippers than you can stack (hence why it’s called a dado stack) to get the proper width. I went with the 6” version, both because it’s recommended for the motor and I can get a wider cut. I did a ½” stack for simplicity, but I’m probably going to expand it to ¾”.
 
After I did the exact same process for the dado insert, I reinstalled the standard blade, and cut through the back of the standard insert to make room for the riving knife. I did this by temporarily reinstalling the OEM insert, and lining up the rip fence to where I needed to cut. I then removed the OEM insert, installed the knife, and put on the new insert. Done!
 
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That’s it for now. The project for this weekend is the pantry doors, perhaps. I’ll at least hit up the lumber yard and get what I need for it.

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