System Pipes

  PUBLIC SERVICE ANNOUNCEMENTS THE EVOLUTION OF BOWL TURNING AT PETERSON WITH GLEN WHELAN & GIACOMO PENZO: Friday from 10-12, DFW Room PETE GEEK MEET: Friday from 2 to 3, Special Events Tent I want begin this morning with some insights Stephen Wilson CPG shared with me on the possible origins of the army style mount which which I found really helpful, and which explains at least indirectly why the original Patent Wear Gap displayed some variations in the 2-4mm distance seen in various shapes of the 1906 catalog. Stephen: “I have spent many years working in the areas of process optimization and process modeling, especially in industrial settings.  I'm wondering if the reason for the Wear Gap [MTI: and by extension the army mount of the System Standard and Premier] is that it is much easier to make a tapered tenon that is 'close enough' to fit into the pipe without a lot of fussy sanding, measuring, fitting, repeating, et cetera.” Mark: “Could you unpack this a bit?” Stephen: “If I design a pipe with a mortise diameter of 4mm, for example, then it must be drilled to precisely 4mm.  Sometimes drilled slightly undersize and then reamed (using a tool called a reamer) to the exact 4mm diameter. “Likewise, the tenon must also be 4mm diameter, or slightly less, to fit in the mortise.  If it is too large, then it must be sanded or otherwise reduced in size to fit into the mortise.  This step can take several iterations to get the perfect size.  If it is too small, then the stem will be loose, and the pipe will not work.  There are several techniques available to increase the size of the tenon.  None of them could be characterized as ‘quick.’ “Thus, for the straight mortise and tenon, a bit of time is required to get the correct fit. “However, if the mortise is drilled to 4mm, plus or minus 0.1mm and the tenon is slightly tapered, for example from 3.9 mm at the end, to 4.1 mm on the stem, then there is no need to ‘fit’ or ‘fine tune’ the size of the tenon, as seen here, illustrating the differences between straight and tapered tenons: “Based on examination of several of my DeLuxe System pipes, I do not believe the mortise is tapered; nor does it need to be. “What does this mean?  From a manufacturing process perspective, the craftsperson can drill 100 4mm mortises. “For straight tenon pipes, the craftsperson turns (on a lathe-like tool) a hundred 4mm tenons.  They all go into a box.  Later, after the bowl has been finished (i.e. shaped, sanded, stained, stamped, and had the silver applied), the assembler takes a stummel and a stem and puts them together.  If they don’t fit, then the sizing steps discussed above must be performed until the correct fit is attained. “For tapered tenon pipes, the assembler takes a stummel and sticks in a stem.  Bag it, box it, done. “Let’s assume that…