Sunday, August 25, 2013

The power of cheap...

I bought a pair of zero clearance inserts when I got my table saw because I did research into it and it seemed that for the optimum cut quality and safety, ZCI's are pretty much required. Since I only had one blade for my saw at the time, I didn't think I'd need more than one for a while. My saw is fairly well tuned, and so I didn't think that it would fall out of alignment any time soon (and it hasn't).

The issue came up when I sent my original combination blade off to be sharpened. So I wouldn't be laid up without a good standard blade, I bought an Irwin Marples blade. This blade is definitely worth the money -- if you want a good blade that won't set you back more than $50, I'd recommend you get one. But when I put it into my saw, I found out that the kerf isn't exactly the same as the Diablo blade I had in there. As a result, the cutout in my ZCI is now not quite right for either blade. The gap has widened to a little over 1/32" on either side, and for something that should be "zero clearance", it's not quite what I want.

My main issue with the aftermarket insert is that it costs about $30 with shipping. I decided that I should just make one of my own. I searched around my garage and found a piece of scrap MDF that must have been a remnant from making my router table. I ripped a 4" piece off the end of it and started working on making my own insert.

The nice thing is that there were a lot of instructions online from other owners of my R4512 saw. Several of them have posted their experiences making inserts along with photos. Using those as a starting point, I was able to put one together with some minor tweaking here and there.

The best thing about making these inserts is that I got to practice a few things that will make my woodworking better. The first is that it requires use of the router table. There were a few blind cuts and some flush trimming to do, and there was no way I was going to try and do that with a handheld router.

Threw on a coat of spar urethane to help protect it from moisture.
It took me a little over an hour to fit everything and make sure that it would work okay in my saw. It worked great, and now I have a proper insert for my Marples blade. I just got my Diablo blade back from sharpening (it's better than frightening), and so tonight I built another insert for that. I haven't cut out the slot in that one yet, but I'll get to that when I have to use that blade again.

The nice thing is that I can make about 15 inserts out of a quarter sheet of MDF. Considering that a quarter sheet of MDF costs under $20, I can make 15 inserts for a little more than a dollar each out of that quarter sheet. That's a heck of a lot better than almost $30 for one insert. I have to make a few for my stacked dado set so I can have a variety of inserts for different width dadoes and rabbets.

Now that I have these done, I know that I can get accurate, tearout-free cuts and I won't have to worry about thin strips falling in between the blade and the insert and getting thrown at my face at 150 miles an hour. I have to pick up the plywood and solid stock for the dresser I'm going to build, so I'll probably try to take care of that tomorrow after work.

Now I have a true ZCI for my Marples Blade.

Red insert for $30...MDF one for basically free...