I am a fan of Winston Moy’s channel too. In fact, it was watching the video that Jerry Gray posted that has me making a supplemental waste board in the first place. I am going to cut both sides of some tight-tolerance pieces, and I need something flatter and more square to the cutter than the bits of MDO scrap I’ve been using as spoiler board.
By “scalloped” cuts for a spindle rotated about the y-axis (tilted left/right) I understood Winston to mean depressions running perpendicular to the direction of the cut – but I admit that I was puzzled by that bit of the video.
It really doesn’t photograph well, but the cuts alternate deep/shallow. Almost 1 mm deeper on the +x cuts than on the -x cuts. The walls of the deeper cuts are the same height front and back. It is not sawtoothed. I put some 0.7mm pencil leads in and across one of the deeper cuts and pulled out my cheap macro lens. It still doesn’t show up well).
I am using a Magnate bottom clearing router bit. Its only 7/8 of an inch across, so it is not as sensitive a measurement as Winston’s improvement-on-a-coat-hanger-tool, but pushing the bit down onto a flat and parallel piece of plywood laid flat on the base of the S03 I don’t see any gaps under the cutter in either the x- or y- direction.
Giving it a little more thought, I’d guess that running this bit with the rotation is causing it to climb out of the cut – which makes me wonder what part of the S03 is deflecting upwards when this happens?
I’ll try running the passes in one direction and report back for further advice and correction in the morning…