Luthiers... need some help

[CJ]

Hey guys.. so I could use a bit of help from you luthiers who probably do this all the time. I've got a bridge, I've got a drill press, and I've got a guitar that needs bridge mounting holes drilled into it. How do I do this?

I've thought of a million ways that I thought would be safe for me to do the drilling, but it seems there's always a way that I could mess up and mis-align a hole and ruin the guitar. My best idea (imo) yet, was to measure out the proper distance length-wise, using stew-mac's calculator, for where to place the bridge. Then run two straight lines coming down from the outside or each side of the neck, and make sure my bridge is placed perfectly symmetrical to those to lines. Then, with the bridge posts on the bridge, set it up in position and lightly tap the top of the bridge with a hammer to leave indents of where the mounting holes go. But that still leaves me with the possible error of not perfectly centering the drill up. So I thought I could carefully measure an X into each hole so as to align the tip of the drill by.

But now that all seems like quite a lot. Would that idea theoretically be ok? Or is there some luthier trick that you guys use to drill these holes much easier?

Any help would be greatly appreciated  :D

[WezV]

measure twice cut (drill) once

what bridge are your using?

[FELINEGUITARS]

measure twice cut (drill) once

what bridge are your using?

+1

Tell us about the bridge and Wez and I will try to give more info

If it is a tunomatic style there will be a little twist to the procedure that you described to help with the intonation

[CJ]

yeah... it's a wilkinson tune-o-matic. obviously i'm going to measure 100 times and cut once, but I don't want to measure the wrong thing 100 times.

[FELINEGUITARS]

As far as setting the positions of the two posts right so that setting intonation is easy
The treble post can be set at the scale length BUT THE BASS POST MUST BE SET  ABOUT 4mm (3/16") FURTHER BACK

Obviously you want to get the two posts equidistant from the centre line
Put a long ruler or straight edge down each side of the neck and draw a line folling the edges of the neck over the body past where the intonation lines will be
Use these 2 lines to make it easier to get a centre line and measure outwards

If in doubt I have to do it myself next week and maybe I could point a video camera at the process to make it easy to see

[CJ]

As far as setting the positions of the two posts right so that setting intonation is easy
The treble post can be set at the scale length BUT THE BASS POST MUST BE SET  ABOUT 4mm (3/16") FURTHER BACK

Obviously you want to get the two posts equidistant from the centre line
Put a long ruler or straight edge down each side of the neck and draw a line folling the edges of the neck over the body past where the intonation lines will be
Use these 2 lines to make it easier to get a centre line and measure outwards

If in doubt I have to do it myself next week and maybe I could point a video camera at the process to make it easy to see

yeah, I was using stew-mac's calculator, and they give you the scale length plus a few mm's to accommodate intonation. and if you could do a video, that'd be great! i've searched everyone online and couldn't find anything. i'm sure it'd help a lot of people.

[WezV]

yeah, what feline said

i usually work from the centre line, but thats because i am usually working on a body i made and they usually have an obvious centre line.  i measure the scale length and put a line perpendicular to the centre line. 

then i measure outwards from the centre to the posts on this line(whatever half the distance between the post centres is).  i mark these positions and add a line parallel to the centre line.  I move the treble back 1mm and the bass back 3mm, not sure where the numbers came from but they work for me.

I then join these two points  with a line which gives me the bridge angle.  If i drilled at this stage the bridge would not quite fit on the posts because its now at an angle and therefore slightly too far apart, i can just move the drill bit slightly inwards to compensate... but usually i put some strings on and do a test fit using this line to help place the bridge.  i dont do this everytime now, but i suggest you do the dry run to ensure its where it should be

sounds long winded but having some strings on really will give you the best bridge position

[CJ]

thanks guys! while I was at the hardware store today, i picked up a set of calipers which should come in handy for many things, this included. anyway, i'm going to be away for a few weeks now, but I'm really looking forward to that video if you get around to in feline! if you can't though, that's fine, I think you guys are plenty help enough so far.