plunge cutting with multifunction (MF) tools

[LCHIEN]

I got a MF tool, a Rockwell Sonicrafter. I was attempting to play with it this weekend.

I found that making notch cuts worked OK using the square-ended "end cut" blades with the blade cutting across the width of a board and the ends of the blade protruding past the board.

I tried to make a through mortise through a 3/4" softwood board by making plunge cuts but it dod not seem to cut well at all after the first 1/16th inch... I suppose there's no where for the cuttings to go so it just jams up the gullets and heats up the wood???

I need to cut some masonite 3.16" or so a 8" x 12" hole... whats the best blade to cut this with? Semicircle running sideways or one of the end cut blades with the cutting edge run almost perpendicular to the masonite?

[Bill in Buena Park]

plunge cutting with multifunction (MF) tools

Loring, I'm surprised about the results you're getting with a straight-in plunge cut, as I've done these with my HF version much deeper than the 1/16in you mention. I'm wondering if, this being an oscillating tool, (1) your workpiece is clamped/immobile, since any movement from the workpiece would hamper the cutting, or (2) that the initial slot you're cutting is wide enough to allow the full oscillation of the blade, so that the blade continues to cut instead of the blade becoming trapped and forcing the tool to oscillate.

For the long cuts in your masonite, I'd recommend the semicircle; sideways to start the cut in the corners, but curved face forward for the length of the cut.

[cabinetman]

I've made plunge cuts with the end cutter to do mortises, and it's limited to the width of the blade. Didn't have a problem with the depth. For long cuts, I've used both the semi-circle, and the end cutter. I had to modify my backsplash for a change to my microwave, and take off ¼" for 30" in ¾" plywood with a laminate face. Used a combination of both blades and worked like a charm. Mine is the HF model, not the high priced Rockwell.

.

[JimD]

I like the arced blade for a long cut like this. It may be because it extends less away from the tool (I also have the HF) but I seem to be able to control it better. I don't remember it clogging up but it's been awhile since I used it.

Jim