I was needing a way to cut a 0.75" channel in some plywood. The usual way of cutting two lines and then chiseling out the middle... I don't like.
So I thought and thought and eventually came up with this....
The idea is a dado blade for a sawzall.
So I got three used sawzall blades (the one in the saw is a thicker metal cutting blade. the others are the big toothed ones for aggressive wood cutting) and cut one into 1.5" chunks. Then very carefully lined the two outside blades up so they are 0.75" apart. and welded the cut pieces into place.
the teeth are all going in the same direction and the blade chunks in the middle will clean out what the side blades can't.
And it works!!! I was so amazed.
First tweek: the two side blades need to hit the wood first then the middle pieces come next. I have them all working on the same level at the same time. This way the sides will guide the middle in and it won't move side to side as much.