Dado question

[Gregg Feldstone]

I just got the Freud Super Dado and watched the DVD, which touts how much better their Dial a Width Dado is. I can see why not worrying about shims is more convienent. Here's my question. If I make a fairly accurate measurement on the low side (smaller Dado) than wouldn't I simply have to nudge the workpiece ever so slightly with the rip fence or Dado sled to make a fine adjustment for fit. Why would anyone take the Dado set apart and start addind more shims instead of what I described?

[glenn bradley]

Multiple cuts or repeatability.

[Bruce Page]

With too much of a nudge you run the risk of ruining your workpiece. I always adjust the width using a scrap piece. Once the dado stack is set, I dado away. I usually only need to adjust the stack once.

[Gary Keedwell]

Gregg,
I always make two passes. Take one pass..measure with calipers... move fence using indicator against fence. By the time some guys are thru fiddlin & diddlin with their shims, i'm already at the assembly table fiddlin and diddlin with my glue-up clamps!

Gary K.

[Jude Tuliszewski]

For one dado cut that would be fine, but as said before repeatability. A project I am finishing up had 88 dado cuts for just one stage of the project. It didn't take long to shim up the dado stack and away I went. If I would have done as you described, I would still be cutting dados. After a little practice you will find it only takes a few minutes to add a shim to a dado stack (WARNING : ALWAYS UNPLUG BEFORE ANY TYPE OF BLADE CHANGES). Make it a step by step process and it goes fast.

[Dave Falkenstein]

I also use the SuperDado. I found that using an accurate caliper to setup the dado set is a far better way than guessing and shimming. I still shim the set, but now I'm not guessing. I usually hit it on the mark the first time, with no need to shim again. Measure the material that will fit into the dado with the caliper, and use the same caliper to measure the thickness of the dado set. Add shims to get the desired width, plus a small shim for a snug fit. Experiment a little and you will find the right fit for your projects. Bumping the fence is pretty inaccurate when you are looking for a tiny adjustment.

[Charles McCracken]

Gregg,

The bevel teeth on the outer blades are taller than the flat teeth so they can shear the fibers and if you make an overlapping cut you will see a very fine (~0.008" deep) v-groove where the outside of one saw runs through the dado.

One way to quickly calculate the shims required for a dado is to unplug the saw, set up the dado set with the correct number of chippers and with too many shims (so the cut will be wider than needed) and make a test cut. Insert the male piece that will fit the dado and fill the remaining gap with shims. The amount of shims required to fill the gap is the amount to remove from the stack.

[Cliff Rohrabacher]

Shims are not a problem at all so long as you are willing to do one thing that you only have to do once for the life time of the dado set.

Measure the tool.
Take a micrometer to each of the shims and know what they are. Make a notation somewhere you can use a dremel and grind it on the shim. This doesn't work quite so wellfor cardboard shims but it does work.
Measure the width of the dado made with the two main cutters and make a note of that.
After that all you need to do is addition to know precisely what your dado cut will be.