I've worked a fair amount with Delrin in the machine shop, and it's actually one of the easier plastics to work with. Teflon, on the other hand, is a pain in the neck. It's very soft and doesn't machine well at all.
----- Original Message ----- From: "David Rastall" <[EMAIL PROTECTED]> To: "Steve Ramey" <[EMAIL PROTECTED]> Cc: <[EMAIL PROTECTED]> Sent: Sunday, January 25, 2004 9:23 PM Subject: Re: More on tuning > Hi Steve, > > I remember from my hammered dulcimer-playing days that delrin was the > material of choice for the bridges. Unfortunately I have no skill at > instrument making, or I would have tried to make one of my own, but the > three HD makers whose instruments I've owned (Dusty Strings, Lost > Valley and Jerry Hudson) all used delrin bridges. With all those > strings (about 30 or so), along with phosphur-bronze wound basses, the > amount of pressure on the HD bridges is huge, but delrin is supposed to > be hard enough to keep from becoming notched over time. If it's that > hard, I doubt if lute strings would have much effect on it. As a > material to make bridge nuts out of, though. I imagine it would be > difficult to cut. > > Regards, > > David Rastall > > On Sunday, January 25, 2004, at 11:22 PM, Steve Ramey wrote: > > > All, > > > > About 20 years ago, I used 1/8" diameter delrin rod for the bridges on > > a hammered dulcimer I built. It's a self-lubricating plastic along > > the line of teflon, but harder. If I recall correctly, I believe I > > was told its hardness is something like Rockwell c 62. > > > > When I made the instrument, I failed to measure twice before cutting > > once and got things out of proportion to the extent I had to use > > bronze wound guitar strings for the lower courses. Admittedly, I > > haven't played (or tuned) the dulcimer for a few years, but when I was > > playing it regularly, I don't recall any particular difficulty tuning > > those strings as compared with tuning the plain music wire strings in > > the upper courses. > > > > There are grooves where the strings cross the bridges. I can barely > > see them, I can feel them with a fingernail, and I can hear the > > strings click into them if I slide the string away from its normal > > position. I believe a delrin bridge would last a long time and might > > alleviate some of the quantum leap unpleasantness we all experience. > > > > I found the delrin rod at a plastics distributor in the Dayton OH area > > where I live. It shouldn't be too terribly hard to come by. > > >
