aka: Spencer
Silverangel Econo A #429
Soliver #001 & #002: A double stack of Pancakes.
Soliver Hand Crafted Mandolins and Mandolin Armrests
Armrests Here -- Mandolins Here
"You can never cross the ocean unless you have the courage
to lose sight of the shore, ...and also a boat with no holes in it.” -anonymous
The tuners on this mandolin are Rubners, bought recently. Luxury nickel w/ ebony buttons, which is the combination I like. They were on sale. I haven't paid attention to newer vs older. What I would really like from Rubner and/or any other tuner manufacturer would be significantly lower tuner mass. And that is especially true when I am making necks tha are both so much lighter and so much stiffer than conventional necks. Heavy tuners don't negate the stiffness advantage of a CF/composite neck, but they do partially detract from the lower mass advantage.
I also have some concern about the Rubner "Moldflon" bearing surfaces on the worms. The "Moldflon, is presumably teflon, aka PTFE. PTFE is a PFAS (Per- or Poly Fluoro Alkyl Substance), dubbed "forever substances". It's not a huge concern in the case of bearing surfaces, due to the small total amount of PTFE on a set of tuner worms. In non-stick cook pans, the PTFE used gives rise to PFOA (perfluoro octanoic acid) and PFOS (perfluoro octane sulfonic acid). Those two, along with other micro plastics, are showing up in water, in soil, and even in the air. So the main concern with teflon coated tuner worms is end-of-life disposal. I asked the Rubner guy one time if there were any concerns about wear of the moldflon bearing surfaces, and he was quick to assert that they are long-wearing. I guess time will tell.
Last edited by Dave Cohen; May-28-2023 at 4:43pm.
Dave Cohen, why aluminum bolt and barrel nut? Weight reduction? I have been using basically the same neck attachment method for the last few years but with steel bolt and nut. Works very well.
Dave Schneider
I'm sure your steel bolt and barrel nut works very well. However, the aluminum version also "works very well". Aluminum has a density of ~2.70 g/cm3, whereas iron has a density of ~7.88 g/cm3. Steel (mostly iron) thus has almost 3x as much mass per unit volume as does aluminum. So if I am going to the trouble to make a composite neck that is both so much stiffer and so much lighter than a conventional wood neck, why would I then add back ~3x as much mass with a steel bolt and steel barrel nut? Btw, I have used the aluminum bolt and barrel nut combination in some guitars and a couple of archtop guitars and an archtop guitar shaped liuto (i.e., a 5-course mandocello). I used two bolts and barrel nuts apiece in those larger instruments. No failures so far.
I wasn’t questioning your ability to build reliable instruments. As a retired journeyman machinist I am aware of the weight difference between aluminum and steel. I am also aware that there is plenty of thread engagement to create a secure joint. Just confirming that it is the weight that influenced your decision.
Dave Schneider
Well since we have strayed from mandolins, here is the current canoe at the Heritage Boatworks at the St Augustine Lighthouse...
A "Bob's Special", 15 ft tandem canoe with white cedar and mahogany (so far).
Last edited by Charles E.; Jun-01-2023 at 12:29pm.
Charley
A bunch of stuff with four strings
I can take a thread off course faster that a jackrabbit can make love!
Timothy F. Lewis
"If brains was lard, that boy couldn't grease a very big skillet" J.D. Clampett
Recently completed this colascione and medieval lute:
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I am a luthier specialising in historical and world stringed instruments. You can see more info at my website.
Jo, you do fascinating work. I would love to visit your shop. Unfortunately that is not likely. Keep up the great work.
Dave Schneider
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