airway engineering

  Lá Fhéile Pádraig sona daoibh! Happy St. Patrick's Day to all of you! Back when the 160th Anniversary pipes came out, I had a chance to ask Giacomo Penzo (Peterson’s pipe specialist) about airway drilling in the 160th and also the System pipes. Recently, I got another opportunity to ask him about the System’s airway bore and mortise. MARK: The 160th Pat OBs all have the airway drilled at the top center of the mortise, with a slight dimple at the base of the mortise. This seems typical across a wide range of Peterson P Lips I've owned. Why not in the center? I'm sure this is naive on my part, but I've had so many people snark at why a Peterson airway hold isn't drilled in the center that I thought I'd ask. These people will go on to say that “it won't pass a pipe cleaner and on a System, I know the answer.  But on other Petersons, I don't. GIACOMO: The reason is just technical on the Pat OB. You know that on the bent pipes the drilling has to follow a different angle than the shank angle to arrive on the bottom of the chamber. For this reason, the draft hole starts lower than the center of the shank, which allows the right quantity of material at the neck to maintain the structural integrity of the material and avoid the little gap on the bottom of the tenon drilling. For the 160th Anniversary pipe, the stem is very thick and bending it was very challenging so to avoid any deformation of the tenon during the bending ( possibly increased by the little gap I just talked about, especially for the 9 mm filter), we opted for the drilling angle you see. Even with the P-Lip, however, you can usually get a pipe cleaner to pass through to the chamber on the 160th Pat OB: bend up the tip of the pipe cleaner before you fit it into the pipe, as shown this the video I made for you:   When a Peterson shape permits us to match the draft hole with the center of the tenon hole, we do. But that's rare and it happens only on semi-bent shapes or bent shapes where the shank angle matches the draft hole angle. Because most of our bent shapes are used for System pipes, we need to drill all of them with the angle for the System—that is, higher than would otherwise be the case—to permit the drilling of the well and guarantee its functionality. We drill the draft hole before the grading process when we don't know what finishing and series a bowl will fall into, which is why we need to drill most of them with the angle for System pipes. If we drilled them lower or in the artisan way before the grading process, most of them wouldn't be suitable for the System. Likewise, if we drilled the draft hole after grading—that is, during the manufacturing process—it would take…