Members Freeman Keller Posted August 26, 2015 Members Share Posted August 26, 2015 There are some guitars built in the '70's that have a funky floating bridge - mostly some Gibson and Epiphones but possibly some other brands. They have a normal wooden bridge with a large slot routed in it, in which a metal piece sits suspended by two knurled knobs. There is a bone or plastic saddle in the middle of the metal piece. The metal piece does not touch the bottom of the slot nor does it fit particularly tightly in the bridge. There simply cannot be good transmission of the mechanical energy from the vibrating string to the top of the guitar. The idea is good, I suppose, in that the player can easily adjust the action by simply turning two little knurled knobs - kind of like an archtop or a ToM on a Les Paul. However from an engineering and sound standpoint it is a terrible idea - we've discussed these several times in the recent past. An old Epi came into my shop recently - actually this is the second time its been there. I fixed a broken headstock on it a couple of years ago. The usual Gibson type of broken headstock (another bad idea but don't get me started). Anyway, the headstock was holding up nicely but the owner had lost one of the little adjusting screws for the bridge. I could hunt around at the hardware store and Mickey Mouse some sort of replacement, but since this is not a valuable vintage instrument I thought "why not fix it right?". I cut a nice little piece of rosewood to fit the slot and glued it in (if it was a valuable vintage instrument that could always be routed back out). The neck angle was fine so there was no reason to worry about that. I have this cool jig for my Dremel that allows me to route slots in saddles in place on the guitar. This allows the slot to be perfectly compensated rather than trying to glue it on in just the right place. Looks like this I routed a 3/32 slot for a standard saddle ( the metal thing is 1/4 wide) and put a nice compensated bone saddle in it. I didn't play it before I started work on it but now it sounds pretty darn good. Link to comment Share on other sites More sharing options...
Members garthman Posted August 26, 2015 Members Share Posted August 26, 2015 My old Eko Ranger VI has one of those adjustable bridges. I did a similar adaptation a few years ago but I just fitted a standard compensated saddle in the slot (base sanded to achieve the right action) and packed the slot with a couple of strips of plastic cut to be flush with the bridge top and finished with a lick of woodfiller of approx same colour as the bridge. It didn't look quite as nice as yours but no-one noticed. However I didn't notice any difference in sound so after a few months I refitted the adjustable bridge. Link to comment Share on other sites More sharing options...
Members guitarcapo Posted August 26, 2015 Members Share Posted August 26, 2015 I have a huge Harmony Sovereign acoustic that had a similar bridge. My solution was a tad different. I took two bone nut blanks an carved them to fill the entire slot. They but against each other between where the b and g string are. This was a perfect spot because I was able to make a nice compensation carve on top. It was really easy to just shape the bone to fill in the slot totally this way. And to return it to stock all you have to do is pull out the two bone pieces and put the floating bridge stored in the case back. Sounds great Link to comment Share on other sites More sharing options...
Members Grant Harding Posted August 26, 2015 Members Share Posted August 26, 2015 Nice. I've converted 3 of those to bone and the difference in tone is noticeable to me. I just use these oversized bone saddle blanks and shape them to fit. In each of the ones I did the correct intonation was further back than the middle of the old contraption, so they also sounded more in tune than before. Only downside is the look of the big chunk of bone. Link to comment Share on other sites More sharing options...
Members DeepEnd Posted August 26, 2015 Members Share Posted August 26, 2015 . . . My solution was a tad different. I took two bone nut blanks an carved them to fill the entire slot. They but against each other between where the b and g string are. . . . This is my preferred method too but wouldn't the two blanks meet between the D and G? Another option would be to superglue two or three saddles together, face to face. Link to comment Share on other sites More sharing options...
Members kwakatak Posted August 28, 2015 Members Share Posted August 28, 2015 Thanks for the write-up, Freeman. I just realized that the cracked bridge of that old Epi Texan 12 string I just acquired has the adjustable bridge. That's got to go but even after borrowing that bridge slotting jig of yours I'm of the mind that the Dremel tool with the plunge router base has to much play for it to be accurate enough when you have nerves as shot as mine are! I'm wondering what the true dimensions of these old Epiphone bridges are> If the Gibson or Martin types that Stewmac sells are close enough can you mount one without having to remove too much finish - or exposing unfinished areas - of the soundboard? Link to comment Share on other sites More sharing options...
Members DeepEnd Posted August 28, 2015 Members Share Posted August 28, 2015 . . . I'm wondering what the true dimensions of these old Epiphone bridges are> If the Gibson or Martin types that Stewmac sells are close enough can you mount one without having to remove too much finish - or exposing unfinished areas - of the soundboard? I suggested that weeks ago and you said you were just going to superglue the cracks. I don't remember if the bridge is pulling up but if it isn't you might as well superglue it. Again, I'd just get a pair of nut blanks and make a really thick saddle. If you want to get crazy, you can compensate both the primaries and octaves. Link to comment Share on other sites More sharing options...
Members Freeman Keller Posted August 28, 2015 Author Members Share Posted August 28, 2015 Thanks for the write-up, Freeman. I just realized that the cracked bridge of that old Epi Texan 12 string I just acquired has the adjustable bridge. That's got to go but even after borrowing that bridge slotting jig of yours I'm of the mind that the Dremel tool with the plunge router base has to much play for it to be accurate enough when you have nerves as shot as mine are! I'm wondering what the true dimensions of these old Epiphone bridges are> If the Gibson or Martin types that Stewmac sells are close enough can you mount one without having to remove too much finish - or exposing unfinished areas - of the soundboard? I just slowly turned each of the adjusting screws at the same time to try to get the big to move directly down with no side play. Next time however I will drill a 3//32 hole in one end of the slot to the correct depth (1/4") and start with the bit all the way down in the hole. Turn the Dremel on slowly and I think it would be just fine. I'll try this on scrap first, but I think it will work. However my slot does fit a bone saddle blank perfectly - I had to lightly sand the sides but not much. I thought of pulling and replacing the bridge and I have two Martin bridges with 2-1/8 and 2-1/4 hole spacing, but unfortunately the holes are not the same distance from the slot. It is approximately the same size and the slot is close to the correct place but you would have to fill the pin holes in the top and bridge plate and redrill them (or get a Martin blank that wasn't drilled and drill it to match the Epi). The Epi bridge also is bolted on to the top - you would have to fill those holes or drill new ones. The other way to do this might be to make two shims 5/64th an sandwich the 3/32 saddle between them. Glue them in with waxed paper on the saddle side and you could eliminate the routing, I'm happy with the way I did it, however and would not hesitate to do it again. Link to comment Share on other sites More sharing options...
Members Grant Harding Posted August 28, 2015 Members Share Posted August 28, 2015 Stewmac or LMI used to sell slightly oversized bridges designed to hide the lines of the old bridge. Link to comment Share on other sites More sharing options...
Members guitarcapo Posted August 31, 2015 Members Share Posted August 31, 2015 I used more of one blank than the other. The easiest way to describe it is that I used close to one whole nut blank for under the G through E wound strings. ...and a smaller "half of a blank" for the E and B part. a typical nut blank is about the right length to get you under all the wound strings. That big chunk of bone looks cool to me. I need to take a pic and post it tonight. Link to comment Share on other sites More sharing options...
Members guitarcapo Posted August 31, 2015 Members Share Posted August 31, 2015 I've tried doing that and at the end of the day I found that it wasn't worth it...compensating the primaries and octaves separately. I always end up with some sort of "chewed-up-on-top affair." that seems too delicate long term under the tension of the strings. The whole thing sort of chips and breaks up on me after a few months of string changes...and my horrible hearing doesn't notice enough difference in intonation to make it worth the effort. Here's a few attempts by other luthiers: Link to comment Share on other sites More sharing options...
Members DeepEnd Posted September 1, 2015 Members Share Posted September 1, 2015 Okay, that makes sense and it looks 'way prettier than when I make a saddle. I usually just file notches on either side of the saddle and don't get a nice continuous bevel like yours. That turned out very well. Link to comment Share on other sites More sharing options...
Members guitarcapo Posted September 2, 2015 Members Share Posted September 2, 2015 I have a sanding block that I use to get the radiused curve of the top of the saddle. The rest is just shaping with a flat file and sandpaper. Lots of trial fitting and shaping. I'm a lot more comfortable approaching it this way compared to taking a Dremel tool to the top of the bridge and making a slot. And I like the idea that it can be returned to stock. It does sound better with a solid bone saddle compared to that shock absorber adjustable bridge. Link to comment Share on other sites More sharing options...
Members kwakatak Posted September 2, 2015 Members Share Posted September 2, 2015 I think I like the shim idea. I have some rosewood blanks that I could use. As for the saddle itself, I still don't trust my handiwork when it comes to finding the compensation. Link to comment Share on other sites More sharing options...
Recommended Posts
Archived
This topic is now archived and is closed to further replies.