Official Luthiers Forum!
http://www.luthiersforum.com/forum/

Initial Bridge Pin Hole Diameter
http://www.luthiersforum.com/forum/viewtopic.php?f=10101&t=25970
Page 1 of 1

Author:  Pat Hawley [ Tue Feb 09, 2010 6:54 pm ]
Post subject:  Initial Bridge Pin Hole Diameter

What initial hole diameter do you start off with for bridge pin holes? I've been using a 3/16" drill as per instructions in the books I've been following. However, now I am starting to think that this is too large. Last night as I was reaming out some bridge pin holes with a tapered reamer, for the first time, I actually took some measurements of the diameters of the bridge pins I got from Stew-Mac. I did this because I was suspecting that they were sitting down nicely into the holes long before a taper was being formed from top to bottom of the hole. Sure enough, when I measured the bridge pins, the 3/16" diameter point was relatively close to the top of the pin. What this says to me is that, with these pins, only the top of the hole needs to be reamed to get the pin sitting low and further, that there will be a space around the pin and the bottom of the hole. I'm not too fussy about this idea because that means the ball on the end of the strings may be sitting in this space rather than on top of the bridge plate where it's supposed to be.

What say you all to this? Do you start off with a smaller diameter bridge pin hole and do more reaming to ensure a taper from top to bottom of the hole?

Thanks,
Pat

Author:  Fred Tellier [ Tue Feb 09, 2010 7:15 pm ]
Post subject:  Re: Initial Bridge Pin Hole Diameter

It depends on the small end diameter of the reamer my 5 degree is 1/8 " so I use 5/32", I would rather ream more than have a too large hole. I think that in the old days they didn't ream just drilled so there was no taper in the hole.

Fred

Author:  Jeff Highland [ Tue Feb 09, 2010 7:21 pm ]
Post subject:  Re: Initial Bridge Pin Hole Diameter

Size of the string ball end on the diagonal 4.8mm I think.
It still has to fit through whatever your pin size.

Author:  bluescreek [ Tue Feb 09, 2010 9:10 pm ]
Post subject:  Re: Initial Bridge Pin Hole Diameter

3/16 the same as martin ,and I can taper the hole to match the pins.

Author:  GregG [ Tue Feb 09, 2010 9:31 pm ]
Post subject:  Re: Initial Bridge Pin Hole Diameter

I've always started with an 1/8" bit and reamed from there, works with my reamer, but it is on the small end of acceptable.

Greg

Author:  Blain [ Tue Feb 09, 2010 9:53 pm ]
Post subject:  Re: Initial Bridge Pin Hole Diameter

I drill 3/16 as well and taper to fit.

Some bridge pins require very little reaming so I do it in small slow steps and check it very frequently.

Author:  Tim L [ Wed Feb 10, 2010 1:17 am ]
Post subject:  Re: Initial Bridge Pin Hole Diameter

I use 5/32" for a 5 degree pin. Ball end will go through if you slot the bridge& bridgeplate.

Page 1 of 1 All times are UTC - 5 hours
Powered by phpBB® Forum Software © phpBB Group
http://www.phpbb.com/