A new take on the Bridge Doctor

[Ryan Mazzocco]

I have a guitar with some really bad bridge belly. If I understand the physics of the pinned bridge correctly... there are both sheer and torque forces on the bridge. but in the case of severe bridge belly the torque force becomes much greater and it becomes more difficult for it to hang on.
well this happened to me. it was my experimental pine top that I'm sure you guys are just about sick to death of hearing about. The top began to bulge severely within a week of it being strung up. after a few more weeks I started to notice the edges of the bridge starting to pop up. before long there was a nice open joint all along the back of the bridge. My saddle was probably leaning forward by a good 10 degrees. The intonation was out; the action was around 12 or 13 thou IIRC... just really bad stuff all the way around.
I figured this could be a good candidate for the bridge doctor. it's cheap and seems pretty easy to install. but the problem I have with it is that you have to drill a hole into your bridge, or use their system which requires you to use their special bridge pins for the system. I didn't really like the idea of either option. So I decided to slightly modify the wheel.

the bridge top bellying, the bridge lifting and the saddle rotating...

The bridge had to come off anyway, so here it goes....

I made the little block out of a piece of 6/4 cherry that I had in the shop.

and in a moment......... the Rest of the Story.....

[Ryan Mazzocco]

And now.... the Rest of the Story...

I didn't want to drill a hole through my bridge to attach the bridge doctor mechanically, so I drilled into the bottom of my bridge to accept the hardwood dowel.

The dowel will go into this hold I drilled into the top of the block.

Now I glued the dowel into the bottom of the bridge.

more still to come....

[Ryan Mazzocco]

I drilled this hole all the way through for the tension rod.

Install the threaded insert to accept the adjusting bolt...

Not for the faint of heart.... I now drill a hole through the top and bridge plate to accept the dowel

glue the bridge back on, intstall the "bridge doctor" and set it back up....

Seems to work pretty good as far as I can tell so far. It definitely helped. My action fell all the way down to .060" which for me is way too low so I had to raise it back up a little... (not a terrible problem to have I guess.)

The only problem I had with it was that the titebond didn't seem to want to bond too well with the end grain of the dowel into the bottom of the bridge. It held okay at first, but then popped loosed later. It never fell out, but I could wiggle it around like a loose tooth. It has to be solid for this to work. So I reglued it with CA and now it's holding great.

[Jason Rodgers]

Yep, that's the idea. The pivot block is pretty big, though! How does it sound, before and after? Good save.

[Ryan Mazzocco]

Maybe a little big. I don't know how big they make the real one. I was afraid to make it too much smaller. I was afraid it could split. As far as the sound: sounds just as bad as it did before. Lol no but really, my ears debt perceive any difference.

[Jason Rodgers]

The Stew-Mac website says "The spruce block is 3/4" x 1-5/8" x 3-3/8" tall. The 1/4"-diameter tension rod is 9" long." I have no experience with this product, but it's a cool solution.

[Ryan Mazzocco]

ah. didn't know the specs would be on there. I'm a little thick, but other than that I'm not far off. In fact mine is a little shorter. I don't remember the exact measurements of mine, I was just kinda wingin' it.
Spruce huh? for some reason I was under the impression the block was spanish cedar. Oh well. I chose cherry because it's hard, light and I have a ton of it.

[Jason Rodgers]

It's interesting that you don't notice much of a difference in sound, but that might be a function of the quality of the top. At least it will keep it together!

[Ryan Mazzocco]

Word on the street is that the real bridge doctor has very little to no effect on the sound, or some claim that it even makes it better...
I'm not sure how it could possibly not change something. It would have to keep the top from vibrating at least a little bit. I can definitely hear the difference between when I play with my forearm on or off the top. seems like it should be similar.
It's all very subjective if you ask me.

[G.S. Monroe]

You know, this might just be something for me to look deeper into. The reason I was looking into mounting a sound post in my guitar was to help curb "bridge belly", by giving the bridge more support because too often my bracing efforts end up lacking. Something like this can be built into the instrument during assembly. it's brilliant.

As for how it would affect the sound, I can't see where it would hurt it much at all. It only reinforces horizontally to counterbalance string tension, and does not inhibit vibration on the vertical very much at all.

Thanks for the posting.

[Jason Rodgers]

Well, Breedlove Guitars pre-loads some (all?) of their instrument lines with the JLD, and even design bracing profiles to work with it, so what you're considering isn't so far out, G.S. Just google Breedlove and Bridge Doctor.

[Barry Daniels]

It can change the sound of a guitar a lot or not much at all. It all depends.

[Michael Lewis]

The bridge Doctor will choke the sound if you put too much pressure on the adjustment post. Also, over time it may need an adjustment due to the wood of the top settling a bit.