When fitting a bridge....

[rowka]

Should the posts be perpendicular to the curvature of the top, or perpendicular to the plane of the sides?

I’m fitting a new CA bridge to my Rover RM-75 and I’m finding I need to remove white a bit of wood from the foot to get the height low enough but as I’m reaching the end I realize I have this choice to make.

[fscotte]

A slight back tilt towards the tailpiece is what I aim for.

[pops1]

A slight back tilt towards the tailpiece is what I aim for.

I agree, but once your bridge fits the top it's easier to take extra wood off the top of the bridge, not the saddle.

[rowka]

Cool. I think I got it.

Now, what’s the trick for laying out the saddle slots?

[Rick Jones]

Cool. I think I got it.
Now, what’s the trick for laying out the saddle slots?

I do it this way both at nut and saddle. That string-spacing guide StewMac sells is fantastic (NFI, just a satisfied customer). Mandolin instructions are a ways down the page.

[Br1ck]

I was very nervous doing this for the first time, in fact I took my mandolin to Gryphon to have them do it. Frank Ford said it wasn't all that critical, I had put together and bound the mandolin, so cutting the slots was comparatively easy.

What I did was sand a nut blank to fit the slot, strung up the E and G outer strings, and lined them up parallel to the edge of the neck. Frank had me look at several mandolins to see the distance from the edge Collings was using. Then I pencil marked the bridge and nut where the outer strings were. Then I had an old nut which I used to mark the inner E a G string spacing. Since my nut was too narrow, I could not use it for the A and D strings, so I measured the inner E and G string distance, divided into thirds then placed the nut with my mark in the center used the nut to mark the courses. I filed the nut just deep enough the strings wouldn't slip.

I filed just enough at the bridge for the G and E strings to hold too. Then I strung up the other strings with some tension, and just eyeballed where the inner strings would go, filed just enough for the strings not to slip. It was pretty much dead on, but if not. the slight groove could easily be filed or sanded off. Once you are happy, you then file the permanent groove depth.

If you have a good nut, this is even easier. Sighting down the length of the string it is easy to see where the inner strings should go.

[Folkmusician.com]

If I have the original bridge, I lay it on the replacement bridge and pencil in the basic top contour. I then chisel/file it along the line (or spindle sander). From there a slight rearward lean while ding the final fitting.

[HoGo]

Fitting the bridge is not particularly difficult thing so many folks do it themselves but what I often see on such attempts (especially when the bridge height needed is very low) is that they do just the minimal necesary fitting of bottom and then remove way too much wood from saddle (either top or bottom) and the saddle cracks after few months. Saddle with less than 1/4" wood above wheels is destined to bend and crack sooner or later. I always remove as much wood as possible from the bottom of the base (often making it full contact) and if absolutely necessary I'd remove some of the nibs at the top of the base and only after that I would lower saddle, but I remember I approached 1/4" only once.