: I bought a wobble dado blade from Harbor freight and finally need to use it.
: Here's my observations: It is difficult to accurately adjust the width of
: the cut.

Ha! They are a bit scary aren't they..
Yeh, the dado width can be a tad bit of work to adjust. It's something you kinda have to work with. Is your's marked with graduations ( mostly inacurate )? Even if they aren't close, they will be good reference points once you get started.
I've use two different brands and with both you have to make test cuts to get them accurate. Kind of a pain, but they WILL work.

: The blade is absolutely frightening to watch when the table saw is on.

I think the thing that is most freightening is the noise and vibration they cause in the saw. If you cut a 0-clearance throat plate and brind it up through that, first you will eliminate alot of the noise. Second, the edge of the cut ( in the throat plate ) will give you a reasonably accurate guide to measure to the fence with.

: It's difficult to set up the distance from the guide.

: There is a slight curve at the back of the notch that's cut. This really
: doesn't bother me.

: The cut is good and clean.

The only time that is realy a problem is when you are looking for a perfect glue joint. There's only contact at the corners. If you are using a different fastening method, they will be fine.

: Anyone had experience with these wild blades? Should I go out and buy a real
: Dado setup?

Yeh, used them for years until I bought a nice stacked set... and to be honest with you, if you are looking for exact fits with the plywood sizes they use now days, you still have to shim those stacks with paper to get the 1/64" differences. The Chippers are all cut to 1/16", 3/32", 1/8", 3/16" and 1/4" or some combination of those. If you want a snug fit with some plywoods you have to make up shims to offset these. So they can often be just as tedious...

Stick with your wobble blade and just play with the adjustment till you get what you want. Once you've used it a couple of times, you will get the idea.

One caution, no matter how shallow/deep you are cutting a dado, DO NOT run your hands on top of the work,over the blade... Sometimes, plywood, for instance, had hollows inside and you can push through that outer veneer and right into the dado. I've seen it.. My Uncle did that and has one joint missing on his right hand.. Make a flat push-stick for flat surfaces. They work great...

Hope this helps!

: Looking for ideas...

: Roger