Dado box joints

[Kizar_Sozay]

I made box joints using a Freud stacked dado set at 9/16" (.5595").  Everything fit pretty good.  I took the stacked set apart and put the regular blade on.  Then I decided I could do better with the depth of cut as the pins were just a skosh short of even.  So I put the stack back on.
 I used the same 9/16" combination as described in the directions (inner and outer blade, two chippers and one black spacer), put the flat sides out, made sure there was clear space between the teeth but it doesn't measure .5595" anymore.  Its about .020 narrower.  That's enough the groove I cut won't fit over the little perpendicular  guide piece in the fence.  I can add shims but why the difference with the same setup?

Made the jig using the William Ng youtube video and my final adjustments for the L-R of the fence is unchanged.

[Stwood_]

May have been a burr, wood chip or something in between the first setup.

[Kizar_Sozay]

May have been a burr, wood chip or something in between the first setup.

The first set up is as directed and was .5595", just what it was supposed to be.  Can't figure out why the second setup is narrower.

[Stwood_]

.020..........different/wrong shim?

[Kizar_Sozay]

.020..........different/wrong shim?

The kit has a bag of shims, two blades, three chippers and two spacers.  The setup asks for one spacer.  I guess tomorrow I'll measure the thickness.  Then I'll add a shim or two and sneak up on the fit.

[Stwood_]

Normally all the shims are different thickness's.



Could be aliens too.........

[Edwin Hackleman]

I made box joints using a Freud stacked dado set at 9/16" (.5595").  Everything fit pretty good.  I took the stacked set apart and put the regular blade on.  Then I decided I could do better with the depth of cut as the pins were just a skosh short of even.  So I put the stack back on.
 I used the same 9/16" combination as described in the directions (inner and outer blade, two chippers and one black spacer), put the flat sides out, made sure there was clear space between the teeth but it doesn't measure .5595" anymore.  Its about .020 narrower.  That's enough the groove I cut won't fit over the little perpendicular  guide piece in the fence.  I can add shims but why the difference with the same setup?

Made the jig using the William Ng youtube video and my final adjustments for the L-R of the fence is unchanged.

I've been making box joints with a stacked dado set for as long as I can remember, unless I use just a single blade and really narrow joints. Those single blade box joints are some of the best I have ever made, but they take much longer to cut.

Your 9/16" box joints are monsters in my book. I've hardly made any of those except for outdoor furniture and softwood. Did you work your way up from smaller box joints and thinner stock, or was this the first box joint that you tried? Show us a Pic of your box joint jig.

[Alan S]

I made box joints using a Freud stacked dado set at 9/16" (.5595").  Everything fit pretty good.  I took the stacked set apart and put the regular blade on.  Then I decided I could do better with the depth of cut as the pins were just a skosh short of even.  So I put the stack back on.
 I used the same 9/16" combination as described in the directions (inner and outer blade, two chippers and one black spacer), put the flat sides out, made sure there was clear space between the teeth but it doesn't measure .5595" anymore.  Its about .020 narrower.  That's enough the groove I cut won't fit over the little perpendicular  guide piece in the fence.  I can add shims but why the difference with the same setup?

Made the jig using the William Ng youtube video and my final adjustments for the L-R of the fence is unchanged.

Is it possible the right and left blade got switched?  That would make the corners a bit less sharp, and with at least some dado sets (I don't know about Freud) would make the cut narrower because the carbide is offset to the outside of the stack on the outside blades.

[Kizar_Sozay]

Is it possible the right and left blade got switched?  That would make the corners a bit less sharp, and with at least some dado sets (I don't know about Freud) would make the cut narrower because the carbide is offset to the outside of the stack on the outside blades.

Freud's video shows the flat side to the outside with the offset carbide turned into the path of the cut.  Its a considerable offset and if I switched the blades to put the offset away from the cut it would be way off, maybe 1/8".

The set comes with spacers AND shims.  the spacers are about as thick as a blade and the shims range from .004 up to about .013.

[Phil S.]

I find that when I stack blades with the tag board and plastic spacers I have, I can get slots of different widths depending on how tight I tighten the blade.  My dado blades are all 1/8" thick except for one that's 1/16 and one 3/32".  I'm not sure if all dado sets are similar, but it seems that the two outside blades with two chippers and a spacer would yield something not too far over 0.5" depending on the thickness of the spacer.  9/16" also should be 0.5625".  I haave been thinking of getting a set of metal shims, but haven't got that done yet.