End pin jack being pulled forward

[Christ Kacoyannakis]

I made two archtops in 2008. I gave one to a friend, as a gift, and kept the other. I noticed yesterday that the end pin jack is being pulled forward by the stranded steel/plastic covered tailpiece fastener. I used a basswood tail block, but inlaid a 1" by 1" piece of hornbeam down the center of the tail block, in hopes of alleviating this problem. Guess it did not work.

Have other people had similar issues? If so, what do you to alleviate or correct it on the problem guitar? What do you do to avoid this?

Creating this type of tailpiece/fastener system is a lot of work, and I am looking for a better way to do it. Maybe use some kind of metal angle mount. But then, I am not sure how to attach the tailpiece to the mount. I would like to use a wood tailpiece, rather than metal, but I am not wedded to the cable type (cello style) fastener.

[Brian Evans]

Is the wood deforming, or is the jack deforming?

[Bob Gramann]

Basswood is pretty soft. Is your inlay moving?

[Alan Carruth]

One piece of hard wood at the surface of a soft block won't help much, I think. Basically it just provides a pivot under the torque load of the endpin; the hard wood is not effected much, but the soft wood still compresses. This will be less effective if the hardwood is on the inside surface, since that gives the load more leverage.

Would it be possible to ream the hole out over size, and put in a metal tube insert? That would at least help spread the load a bit. Another possibility would be to make up a suitably 'art deco' inlay of some thickness to adorn the hole, and also spread the load.

[John Clifford]

This is one of the reasons I have abandoned the Benedetto cello style tailpiece fastener. I think D’Aquisto had a better idea, which was to make a 1/2 wood and 1/2 metal hinge. The top piece is wood and the end piece is metal. A steel pin runs through both to make the hinge. I’ll try to add a couple pictures of the one I just made. This uses 1/2 of a brass hinge I got from a marine supply company, but you could make your own out of brass stock.

[Randolph Rhett]

There used to be a person on this forum who would put a screw vertically through the top and into the tail block. The tail piece had a keyhole of brass(?) epoxied into a recess. They keyhole slipped over the end of the screw and nothing hung over the edge of the guitar. He was Italian and made some of the sexiest looking guitars I've ever seen. Maybe one of the longtimers here remembers his name. The tailpiece without a hinge or strap LOOKED amazing. I don't know if there were problems down the road with that system, and I've never done it. But if it worked, it was one seriously cool take.

The other problem than the hole deforming is the endpin snapping. I posted here about a year ago an end pin jack that just snapped under the pressure of the strings. Luckily my heart didn't stop at the loud explosion when it gave.

IMG_3678 (1).jpg (21.07 KiB) Viewed 29574 times

Mystery Chinese pot metal that obviously didn't have the strength for the job. I've since switched to putting the jack on the rim and using a brass endpin from LMI.

[Christ Kacoyannakis]

If I recall correctly, my hornbeam insert was not just a small insert of wood on the outside. It was one inch wide and one inch deep and it ran from rim to rim in the tailblock. Thought that would be enough, but then again, there are six metal strings tuned to pitch pulling on it. I think that the wood is deforming, and not the end pin jack. The tailpieces on these guitars were one of the hardest things. I ruined 3 or 4 of them, trying to make them myself, so I finally but the premade Benedetto ones from LMI, and then I changed the shape a bit, and arched the top surface to match the radius of my fretboard, and added an inlay.

I really need to come up with something different, because I just didn't like it doing it, and now I see a huge problem with it. I do believe I remember the maker with the screw in the top to hold the tailpiece. I will have to look that up. Ken Parker does a similar design, where he makes up (himself) a mokume gane sandwhich of metal with copper and nickel and forms it into a tailpiece, which he screws into the top of the tailblock. Very cool. The one thing about Ken Parker is that he has spent a huge amount of time trying to figure everything out about the archtop, what works, what doesn't work, what could be better. Very cool stuff. Maybe I'll give him a call.

Thanks guys, and happy holidays!

[Peter Wilcox]

i made a similar tailpiece for an experimental resophonic guitar a few years ago, held on to the tailblock by my favorite hardware, a drywall screw.

[John Clifford]

Peter, did the drywall screw actually hold up to the string tension?

[Peter Wilcox]

John, it's been hanging strung up for 7+ years and very seldom played, but so far so good. If I were to make a gigging guitar with the same tailpiece design, I'd use a thicker screw of better steel.

[Christ Kacoyannakis]

Thanks, Peter. What was your tailblock wood? That seems to be my biggest problem.

[Peter Wilcox]

Christ, the wood is alder (because I literally have tons of it). The blocks aren't going to move or deform, as they are large and well buttressed by the metal pan and internal braces. Alder seems to be adequate for holding the screw straight, plus the metal pan probably helps.

[Christ Kacoyannakis]

I don't think my basswood with the hornbeam insert tailblock deformed. I think the wood compressed from the strings pulling the end pin jack forward.

[Jim Hepler]

I don't want to hijack this thread, but I am quite fascinated by Peter's roasting pan resonator. I'd love to see any other info about that. I guess I'm asking for a new thread on that one Peter. I'm also curious to see what the problem turns out to be with the travelling jack and what solution you come up with, so I will be following this one eagerly as well.

[Peter Wilcox]

Jim, that build was part of a challenge here in 2010 when I built 4 resophonic guitars from scrounged/unusual parts like 5 gallon buckets, toilet seat, roasting pan, fiberglass and plastic dishes Since none of them had proper cones and bridges, their sound left something to be desired. Unfortunately, at that time, threads scrolled down off the site and were apparently lost forever, so it's no longer available. However, I can post a summary of its construction in the near future, probably in the builds/tutorials section of MIMF. Anyway, here's a pic of the completed guitars.

[Jim Hepler]

That would be great Peter. Thanks a lot. I'll keep an eye out for it.
Jim

[Randolph Rhett]

This is one of the reasons I have abandoned the Benedetto cello style tailpiece fastener. I think D’Aquisto had a better idea, which was to make a 1/2 wood and 1/2 metal hinge. The top piece is wood and the end piece is metal. A steel pin runs through both to make the hinge. I’ll try to add a couple pictures of the one I just made. This uses 1/2 of a brass hinge I got from a marine supply company, but you could make your own out of brass stock.

BTW Jim, that is one seriously beefy brass hinge. Can you share where that came from?

[John Clifford]

This is one of the reasons I have abandoned the Benedetto cello style tailpiece fastener. I think D’Aquisto had a better idea, which was to make a 1/2 wood and 1/2 metal hinge. The top piece is wood and the end piece is metal. A steel pin runs through both to make the hinge. I’ll try to add a couple pictures of the one I just made. This uses 1/2 of a brass hinge I got from a marine supply company, but you could make your own out of brass stock.

BTW Jim, that is one seriously beefy brass hinge. Can you share where that came from?

Randolph, I'm not sure if you were addressing me or Jim, but the brass hinge part shown in my photos above came from a Whitecap brass strap hinge, part #S-604BC. You can find these on numerous marine supply websites, or amazon. It's heavier than it needs to be, but I like solid hardware and I don't think it hurts to add some mass at the tail end.

[Alan Carruth]

I recently delivered an archtop with a 'different' tailpiece , and was dismayed when this thread came up to find that I hadn't gotten a picture of it. Fortunately, the customer is also a student of mine, and he brought it in Saturday, so I was able to get a couple of shots.

The guitar was intended as, in some sense, homage to a Loar L-5. The intent was to come up with an instrument that would work well for acoustic jazz in the 20's-30's style. Normally I would use a wood tailpiece, but the customer thought that since the original was metal, we should go that way. I didn't like the look of the Gibson style tailpieces, so I fell back on a technique I'd used a couple of years ago to make a latch for a folding harp guitar. The issue was that the brass I can get that is thick enough to take the load is too thick for me to bend, so I had to come up with a way to piece it together. I based it on the old transitional 'infill plane' design, whereby a wood plane could be plated with metal. The metal, brass or steel, plates were cut to fit around a wood core, and screwed on. the plates were dovetailed together at the edges, and once mounted the joints were peened to tighten them up. The metal was then filed off level and polished. Here's the fixed part of the hinge, in walnut and brass with a stainless rod for the pivot. You can easily see the dovetail joints. The flat head brass screws that hold the wood and metal together are filed off flush. The fillister head screws are the ones that hold the tailpiece onto the guitar.

And here is a shot of the whole thing.

The wood part of the trapeze is hornbeam, that has been stained to look like walnut. The strings are retained as per my reading of the Elliot pinless design.

The next time the customer comes up we'll put in an endpin. He doesn't normally play standing, but wants one if he needs it.

[John Clifford]

Very cool looking tailpiece, Alan. So are there pins going through the ball ends of the strings to hold them in place?

I'm guessing this ended up being pretty heavy. How do you think that affected the sound, if at all?