Hand Tools Archive

Some retracting to do..
Response To:
Re: LV skew shooter ()

Wiley Horne--So. Calif.
The formula I posted is theoretically correct for skews achieved by ‘rotating’ the whole plane throat, in the same horizontal plane. But on re-reading the thread, I see David’s current thinking is to tilt the iron to get the skew, which creates a set of different angles. These angles do not fit the formula, and make Derek’s question very interesting. Can’t say more without knowing whether David is going to tilt-only or use some combination of tilt-rotate. For example, if David goes tilt-only to get the skew, then a full-width shaving will run straight up the 42-degree bedding, and there will be no reduction in cutting angle. Further, if the plane is BD, then the skew would reduce the included angle, and would seem to increase the clearance a little, while leaving the attack angle at 42 degrees. On the other hand, if the plane were BU (and obviously at lower bedding), the tilt-only approach would reduce the attack angle, because the shaving would be moving slantwise to the grind on the blade.

All the above truly does get us into the realm of angels dancing on the head of a pin. But it seems to me that BU versus BD may be a big deal affecting thin shavings, due to the long cantilever of the BD iron beyond its bedding support. The lower the bedding angle, the thicker the iron, and the thicker the sole—all combine to increase the cantilever. Perhaps a chipbreaker would stabilize the blade tip against vibration, but the BU configuration would start with the advantage of having bedding support closer to the blade edge.

That is all. Over and out.


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