bridge placement

Materials used - making - placing - gluing to the sound-board <-----<<< got to get this right!
tim crain 54
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Location: Dallas, TX
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bridge placement

Post by tim crain 54 » Sat Nov 23, 2013 2:13 pm

I finally came up with my bridge design and finished the bridge last weekend. I am at the point of locating the bridge so I can make the mask and proceed with the finish. So once more I am going to ask for input on compensation just so I have as much information as possible before making the decision on the saddle location/bridge placement. The scale length is 24.75" (628.65mm) and the plans call for approx. .130" (3.30mm) compensation at the high E string. This works out to approx. .1730" (4.4mm) at the center of the slot (in between the 3rd and 4th string) with my 3% slot angle. This is a bit more than the .15" (3.81mm) recomended by Cupiano though his calculations are for scales of 25" to 25.75" and from what I have read the shorter the scale the greater the amount of compensation needed. Looking through my books (Kinkead, Young, Sloan) the measurements on my plans seem to be in the ball park though all of the information in the books is based on longer scale lengths, approx. 25.4. I was wondering if any of you had built a J185 using the Scott Antes plans or any other 24.75 scale guitar and what compensation you used. I attached a few pic of the bridge, the holes in the "wings are for locating pins and will be covered by a yet to be determined inlay. Thanks again in advance for any input, I know this is a very critical step and I am pretty nervous about it.

PS: Sorry about getting the pic sequence reversed, one day I WILL figure it out!!
Attachments
finished bridge with another blank for reference
finished bridge with another blank for reference
IMG_1662.JPG (94.2 KiB) Viewed 1299 times
rough shape with the saddle fitted
rough shape with the saddle fitted
IMG_1648.JPG (151.51 KiB) Viewed 1299 times
cutting the slot
cutting the slot
IMG_1646.JPG (115.88 KiB) Viewed 1299 times
template, laying out on the blank
template, laying out on the blank
IMG_1645.JPG (150.09 KiB) Viewed 1299 times

ken cierp
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Joined: Tue Dec 13, 2011 11:23 pm

Re: bridge palcement

Post by ken cierp » Sat Nov 23, 2013 6:42 pm

Because of all the chatter and erroneous information regarding intonation and compensation other than selling our tools for bridge/saddle placement that put it in the right place, I don't get involved in explaining and detailing dimensions or the process. But I will say that these are incorrect assertions

The scale length is 24.75" (628.65mm) and the plans call for approx. .130" (3.30mm) compensation at the high E string
I have read the shorter the scale the greater the amount of compensation needed.

tim crain 54
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Re: bridge palcement

Post by tim crain 54 » Sat Nov 23, 2013 9:51 pm

Thanks Ken.

Dave Bagwill
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Re: bridge palcement

Post by Dave Bagwill » Sat Nov 23, 2013 10:14 pm

It is also useful to use a wider saddle, it gives greater flexibility for intonation. Mike Doolin, for instance, uses a 1/4" thick saddle. I've done that as well and it works great. But at least 1/8" if you can. 3/32" has been used on about a zillion guitars and can be made to work, but a little more thickness makes things much easier.
-Under permanent construction

Lonnie B
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Joined: Thu Sep 05, 2013 7:42 pm

Re: bridge palcement

Post by Lonnie B » Sun Nov 24, 2013 12:11 am

Well those appear to be the pictures from Kinkeade's book doesn't his numbers work? I just finished his book not two hours ago.

tim crain 54
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Re: bridge palcement

Post by tim crain 54 » Sun Nov 24, 2013 1:55 am

Lonnie I'm not sure if Kinkead's measurements work or not that is why I was asking for input. They seem to be in the ball park to what I have in mind but being my first acoustic build and not having the luxury of and adjustable bridge I was hoping for some input from of the more seasoned builders. Bridge placement being one of the most critical steps in construction I wanted as much info as possible before pulling the trigger. Thanks for your interest and I will let you know how it goes. Thanks again, Tim

tim crain 54
Posts: 102
Joined: Sun Jul 08, 2012 2:44 pm
Location: Dallas, TX
Contact:

Re: bridge palcement

Post by tim crain 54 » Sun Nov 24, 2013 2:00 am

Dave I have a 1/8th - 3mm saddle so not a lot of room for error. I need to be close right from the start then I can make minor adjustments from there. Next time may be a wider bridge is the way to go. Thanks much for the input, I need to look at all the options before I position this thing. Thanks again, Tim

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