Friday, October 26, 2018

The Faceted Pommel


The latest endeavor in creating unique pommels for Classical Fencing weapons!  Amazing that such a simple looking item can be so complicated to make.  Unlike most pommels available on the market, this one is not cast in a mold.  Rather, it is machined and milled from a solid brass slug as seen on the left.  Like previous creations, it is first turned and drilled on a metal lathe then tapped for a 6mm thread.  The complexity comes in accurately setting and reproducing each of the six facets at exactly the same angle on a vertical mill (non-CNC).

Cutting angles on a vertical mill isn't particularly difficult but this pommel required each cut to be 60 degrees apart, cut exactly to the same depth and perfectly tapered from the centerline at 6 degrees.  The part had to be moved for each cut so exact alignment for each cut position and depth was critical.

My drawings and calculations for the final weight of the pommel (100 grams) required an extremely exact taper angle.  Now, I don't know about you but I don't have a protractor that can accurately set a 6 degree angle (+ or - a few minutes) and I wasn't about to pay several hundred dollars for a set of machinist's angle templates.  The solution came from Joe Pieczynski at Advanced Innovations in Austin, Texas.  His videos showed me how to use the X and Y axis table on the mill (accurate to thousandths of an inch) and some simple trigonometry tables to create a 6 degree template to position the part and accurately reproduce each facet cut.  Not only did all the points meet drawing specifications, the part weighed in at exactly 98 grams!  I've already cut some additional angle templates to provide stepped weight variations for custom weapon balance.

For now, this pommel is one of a kind so I'll have to save it for a very special foil worthy of the design.  The successful results also open the door to more artistic variations that, for now, are still just in my head.


No comments:

Post a Comment