Saturday, April 5, 2014

Box Joint Jig IV

Problem solved! I tinkered with the new Freud Box Joint Blade set again today and realized exactly what the issue is. It's not the blades at all - its the arbor on my table saw.

Either by design or by wear over the last 10 yrs or so the inside (left side on the photo above) of the arbor screw threads have worn down and created a slight drop next to the solid 5/8-inch diameter section. The solid portion is about 1/6-inch wide... suitable for a thin kerf blade. But if you put a second one next to it, like the new Freud box joint blade, it "falls" into the gap... just far enough to cause a loose fit and the 1/32 inch cutting differential I was seeing. I suppose I could look into replacing the arbor, but from fairly recent experience I know what's involved with taking this saw apart... and it's quite a chore. For the sake of cutting box joints with a custom set of blades that idea is an immediate non-starter.

So nuts to it. I put on my old Freud dado stack and set them up for a 3/8-in cut. Perfecto! They are little bit noisier than the newer blades but they work just fine. And for whatever unexplainable reason they do not fall into the gap like the newer blades. I think it's because they are a little bit wider and span the gap enough. At any rate the tops of all the cuts are clean with these blades, and that's what I want anyway. I did learn that every new set of joints, once the setup has been dialed in, requires a fresh new backing plate. I'll go thru a lot of these over time.

So I'll save about $100 by returning the newer Freud kit and using my old dado stack. The savings will probably get spent before my account even gets credited!

I have the option of using this with my router station setup as well. The miter sled inserts work for use at both the saw blades or at the router. This is a bit of dumb luck because I didn't check it the other day before installing the inserts. There will be a minor bit of trimming the first time I use it at the router, but after that it'll be good to go. Cool.

I'm already wondering where I'll use it most often and somehow I think the router might produce the best results. To prove it I just ordered a nice new set of carbide spiral bits ... been wanting a few of those anyway. See... savings almost gone already! :)

Post Script: Thanks to a great tip by Michael Olson I may hold off on returning these blades after all. Michael had the same problem and posted an in situ modification using JB Weld in this video on YouTube. If my local Home Depot or Lowe's has some of this stuff I just might give it a shot! Thanks, Michael!

You've got to hand it to the interweb these days... just about all the answers are there somewhere!


  1. Hooray for Hollywood Hein! I'm glad you solved that as I have been racking my brain on how this could happen and never once did arbor wear come up! I was thinking one blade was somehow off center but couldn't come up with how, and you know I don't have much brain racking left! :-) Glad you figured it out!

  2. Well that repair saved him a few hundred dollars and a lot of time!