Shopsmith Forums

I've got an older Craftsman adjustable dado blade (the type where you turn a dial to offset the blade angle). It was in a box of stuff that came with one of the Shopsmith's. Using it seems straightforward enough, loosen it up, dial in the width, tighten it down and see if it needs tweaking. So, I can get the width I need.

However, it is cutting a slanted slot, one side is deeper than the other. What gives?

I know I have my table squared to the headstock/blade when my standard blade is on there. And, this thing cuts an uneven notch regardless of which Shopsmith I have it mounted on.

Is there an adjustment to fix this? I know the real fix would be a real dado blade setup, but that just simply is not in the budget right now.

Please don't make me use my router for this, as I've already made a really neat jig to do this on my tablesaw setup.

These wobble dado sets typically cut a slightly round bottom dado but I have never heard of your situation before.

About the only way that could happen is that the table has slipped or that it is flexing during the cut. Otherwise the cut "has" to be the same on both sides.
Maybe the cutter is a little dull and pushing hard on the stock.

This reminds me of one episode of the old Loretta Young show where her character kept cutting out paper dolls (in a line) and every time she unfolded them and stretched them out there was always magically a tall one in the middle of the batch...


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I have the Magna dial a width wobble blade and it too cuts slightly deeper on one side(as well as the curved bottom).

I have looked for a source of the difference, and detect none on the blade itself. It is indeed round!

That leaves the tapered washers as the only remaining culprit. The Magna version that I have consists of 4 tapered washers. Two of those are registered to the blade(holes/slots and projections). The adjustable washers are connected by a spur gear that also has a hole for an adjusting tool(square shank).

It is imperative that the 4 washers be in sync with each other(especially the two adjustable ones, but the 'fixed' tapered washers on the blade must also be positioned correctly).

When the adjustable washers are adjusted to '0' (no wobble) the blade should be running true(no wobble). Adjusting the 'wobble' should do so equally on opposing points(teeth) of the blade. This is at the mercy of the washer taper profile.

A deeper cut on one side is an indication of less 'wobble' in that 'direction'.

The arbor runs true, but the blade is positioned askance by the washers.

I tried to correct all this by careful washer positioning(there are several wrong combinations which will be readily apparent), and shimming. I gave up since the curved bottom was a constant. I have only fairly recently gotten a decent stack set. For 'decades' I resorted to the multiple pass sequence.

If yours are not connected(move simultaneously) then adjusting each side separately may reduce the disparity.

First, a correction. I do have a Craftsman wobble dado, but the one giving me grief is a Shopsmith original.

Having both, and seeing the Craftsman has many more teeth (i.e. smoother cut), I thought I'd mount the offbrand and use it. However, the center hole on it is larger than the 5/8" dado arbor I had in my drawer of SS stuff. No joy.

For some reason, call it luck, intuition, karma, whatever, I decided to pull the SS wobble dado off it's arbor and put it on the other one. Oh, now I remember. I was thinking maybe the washers were turned wrong or something. Anyway, when I pulled the blade off the arbor, here is what I found:

[ATTACH]14746[/ATTACH]

Hard to get a good close-up picture, so I'll explain it. There is a significant wear groove on the arbor's shaft. The groove allows enough slop to cant the blade, thus the uneven cut.

Mounted the SS wobbly to the 2nd arbor, and, PRESTO, nice clean, SQUARE cuts.

OK, back to the project. Christmas is only 41 days away!!

I don't know if this is a magna wobble or not, but it looks like one.
The black marks are where the blade beat on the insert.
[ATTACH]14747[/ATTACH]

It makes dados and grooves that are reasonably square and flat. However there is a definate dip near one side in the 1/2" and a bigger dip in the 1/4" dado. The 3/4" is really flat and smooth.
1/2" is on the left, 3/4" in the middle and 1/4" on the right.
[ATTACH]14750[/ATTACH]

But when a board is inserted the dips aren't so bad anymore
[ATTACH]14749[/ATTACH]

I've made lots of box joints with the 1/4" setting.
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