I have seen some nice CBG bridges for sale on Gitty's site and other places.
But how do you plan a build that can use one, without repeated teardown - mod - reassemble cycles? I always seem to end up making the nut and bridge last, using scraps from my cutoff pile to prop up the strings till the action height is a little above what I'm looking for so that there is room to cut the nut grooves down and then fabricate a bridge that matches my stack of scraps and start shaving it down to the correct action height.
So, how do you plan the build so that one of these pre-made bridges is only about a millimeter or less too tall and can be tweaked at the benchtop sanding station?
I usually make a full scale drawing of the box and neck assembled so that I can see the likely bridge height If you use a glue on fret board, then it should be in the drawing as well. Staples has rolls of drawing paper for a few bucks. It is perfect for a CBG drawing.
You can tilt the head of the neck down, which will of course lead to a higher bridge height (with everything else remaining unchanged). So, that becomes a variable you can use to adjust the build for a specific bridge height.
With a good drawing, you can match the build to the bridge you intend to use and not have a lot of "tweaking" to do.
Do you include fret height and string action/height above the frets in the drawing? that's why I end up making the bridge to fit as my last step, I start working the action above the frets and cut a bridge to fit whatever I ended up with.
I usually draw in the nut and a fret at the 12th. I can then draw a "string line" all the way from the nut to the bottom of the drawing at my preferred action height.
That being said, there is always "tweaking" to get the bridge height such that your action is where you want. My approach is to try to minimize the tweaking. I've built a dozen or so CBGs using my drawing and I like the lack of surprises.
neat, I'll have to give it a try
"mount to a platform ..... " that sparked an idea.... mount them and prototype from there...
I could start with the fretboard nut bridge and tailpiece (or hardtail) clamped to my worktable, run a string, and with some shims and wedges work out how the height difference between the bottom of the bridge and the bottom of the fretboard, bridge to tail piece spacing & height for a good not ridiculous break angle, decide at that point on scale length and which box to use...etc
ok, I gotta finish the 3 on my worktable so that I can try this...
Particularly with c b g's,i'd reckon trying to build around a fixed bridge height as a starter, to be making it a lot harder on yourself than it needs to be,unless you include an adjustable neck angle. any neck raising under tension ,or box top compression will need to be accounted for and with no bridge adjustment available,it will limit your ability to set a good action height.Definitely a good layout will get you pretty close,but there will be variables in top thicknesses/resistance to compression/neck mount rigidity etc,which to my mind are easier overcome by just shaving a bit off your bridge /saddle
A trick that I use when making my bridges involves fishing line and a small wood wedge. I measure the height between the 1st and 2ed fret then usually add 0.010" to that number. This number can be more or less depending on how high or low of a action you are shooting for, but 0.010" seems to be a good general number to start with. I then stack feeler gauges to that height and hold them tight against the fret side of the nut to use as a stop to cut my string slots in the nut. A rubber band works well for holding the feelers on the neck. When you hit the feeler gauges.....stop. Once I have the nut cut it is a simple process to tie fishing line to one of the middle tuners and pull the line tight across a wedged shape piece of wood located at the bridge location and measure the height at the 12th fret. I simply move the wedge back and forth until I get the height I want above the fret, then mark and measure the height of the mark on the wedge. Depending on how you make your bridge, you can allow for any slots you need to cut for strings..........but this method will get you very close to the finished height of the bridge the first time out. Hope this helps you out ;-)
Great tips here, Rooster! Thanks for the detail. I'm closing in on my very first build and was a bit stumped on how to set the bridge height.
The general consensus seems to be 1-2 mm at the first fret, and 2-3 at the 12th. As you say, once the nut height / slots are cut to set the action at the top, basically a string-line to the tailpiece and a wedge to dial it in and you're golden. Brilliant. (I'm reiterating to solidify it in my coconut ;) ).
May I ask - how do you slot your nut / bridge (assuming one is using bone / Corian)? Is it critical to use a fret file the same gauge as the string? I did order the all-in one 'welder's' file set from the shop, here... just wondering how important this is or if there are other tricks of the trade to slot these puppies.
If you meant by welders file set gas welding nozzle cleaners they're ideal for making nuts.forthe skinny strings start the groove with a three square needle file and use a saw blade that's close to the string thickness for the fatter ones
Thanks Michael. I did mean the 'nozzle cleaners'. I found a good video this morning for filing the nut... going to follow your advice / follow this video.
Maybe this will help someone else out:
I have this dilemma on my next build. My box is definitely a one off that I will never replace and the design of the box is dictating the placement of neck end and bridge height.
My idea is to build the entire neck and tail with strings nut tuners ect with bridge placement before I even touch the box. Hopefully by doing it this way I can just drop the whole assembly into the box and refine it all as I cut the box to fit the skeleton guitar.
Bridge height should be adjustable by determining how deep I cut the box sides.
Has anyone did it this way before and have you any tips for me?
Yep, nut and bridge are the last things I make too, but also, they end up being pretty much the same height. If I have the neck flush with the top, then a 1/4" fretboard on top of that, then the height of the frets,plus a bit for "action" my bridge ends up needing to be about 3/8-1/2 " high (depending on if I have used any back angle on the neck). I imagine Gitty prob makes theirs about that height or a bit over, and you can sand it down to the height needed?