Set-up question

[Strathspey]

In Mike Compton's last Co-mando chat, he mentions that he sets his mandolin strings up at 5/64" at the 12th fret. If this on the treble side or the bass? Or is this an average height?

He also mentions "Having the bridge fitted at a very slight lean backwards (about 85%-88% to the top) seems to have the effect of driving the top more, as it does on fiddles." By backwards, does he mean toward the tailpiece - which I'm sure he does.

Any other tips on setting-up a mandolin? Compton considers 5/64 to be medium height, what would be high or low?

Matt

[sunburst]

I've never been able to think in 64ths. I find that 1/16" at the E string to 1/8" at the G string is a good starting point for string height (measured from the 12th fret to the bottom of the string). Some players like lower, some higher.

I've heard and read a lot about violin bridges leaning back toward the tailpiece to more nearly bisect the break angle of the strings. I was taught basic violin set-up by a schooled violin maker. Here's what I learned about bridges:
A violin bridge blank is wedge shaped with the bridge feet at the wide end of the wedge and the top of the bridge being the narrow end of the wedge. After the feet are fit to the top the bridge is cut to the correct height by simply cutting material from the top. The top surface gets wider, because of the wedge shape, and more importantly to this discussion, the outside edges get wider than the center because of the arch of the strings.
The top edge should be 1.1mm wide. To achieve this a "chest" is carved on the bridge surface. The surface toward the tailpiece is left flat and the chest is carved on the surface toward the neck. The chest is a dome shape that gets the bridge top down to the right width while keeping the bridge top a straight line (looking straight down on it) so that all strings are the same length.
Now, the bridge is fit to the top at a 90 degree angle to a tangent to the top arch, but looks like it leans toward the tailpiece because of the chest.

Sorry it took so many words to explain why violin bridges don't really lean, but I feel like a mandolin bridge should be 90 degrees to a tangent to the top arch in order to most effectively drive the top.

[MANDOLINMYSTER]

I can't think in 64th's or any number when it comes to string height, just lower the strings to they buzz, then raise it till it doesn't buzz for your playing style and you will have perfect string height, this only works if the neck is true of course

[Chris Baird]

I think the bridge should be fitted towards the tailpiece for a couple reasons. #The first being that when the stingload is transferred to the top the bridge area sinks a bit and pitches the bridge forward ever so slightly. #Second, it seems to me that the vector of force created by the string breakover angle is not perpendicular to the plane of the top and hence to match that vector more closely the bridge will have to slant towards the tailpiece a bit but not so far as to compromise driving the top perpendicularly.