Newbie Design Question

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Newbie Design Question

Postby Andrew Doyle » Sat Nov 19, 2016 1:56 pm

Hey I was wondering if anyone could give me some advice for designing the bends in the ribs of an acoustic? Like do people just draw something they think look acceptable or is there a way to put a set radius on them at each bend? Even if someone could point me in the direction of some books or anything would be a great thanks!
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Re: Newbie Design Question

Postby Brian Evans » Sat Nov 19, 2016 3:06 pm

You can do two things, and I've done both. You can grab a guitar you like the shape of and trace it out, and use that shape. You don't need to know what the radius of any curve is, you just use the pattern, make your outside mold, and bend your sides to suit. The other way is to have an idea in mind, sketch it out, draw it full size using whatever tools you like. I did that, made a pattern, made a mold, bent the sides to suit and carry on building. In my case I used a 1.5" radius for the waist of the guitar for no other reason than it looked right and I have a 3" diameter sanding drum that I like to use to true up the sides.

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Re: Newbie Design Question

Postby Bryan Bear » Sat Nov 19, 2016 3:13 pm

There are lots of ways to do this, you just need to find out what works for you. Remember when designing your own shape that you probably don't want to veer too far away from proven dimension, especially not if you are new to the craft. Once you get a better handle on making guitars you can start to push the envelope more. Also, you probably want to make sure it fits in a readily available case.

The book "gutarmaking :tradition and technology" is a good place to start for a lot of reasons. It also walks through designing a body shape.

Gthang is a program you can download for free (google search) that helps you lay out a body shape digitally. It takes a little while to get the hang of it but once you do, it is a great tool.

You could also just map out your key dimensions and go at it with french curves and a lot of erasing to get a shape that is pleasing to your eye.

EDIT: I'll also add that if you are new to side bending it is probably better to avoid really tight bends at first.

Take care of your feet and your feet will take care of you.
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Re: Newbie Design Question

Postby Andrew Doyle » Sat Nov 19, 2016 4:40 pm

Thanks for the advice :D
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Re: Newbie Design Question

Postby Alan Carruth » Sat Nov 19, 2016 7:25 pm

A useful rule to keep in mind is to never build a guitar you can't buy a case for.

The 'bible' around my shop is: "Guitars, music, history, construction and players, from the Renaissance to Rock" by Tom and Mary Anne Evans. It's an oldie but a goodie. It has lots of (small, black and white) pictures of guitars from every era, along with a table of the main measurements for each one.
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Re: Newbie Design Question

Postby David King » Wed Nov 23, 2016 1:27 pm

You might want to invest in some drafting tools or make your own. Slicing up some thin oak veneer strips about 1/16" thick and using them to trace "fair curves" will be helpful. Shipbuilders used white pine but I find white oak works well for me. Shipbuilders used metal "ducks" to hold the wood strips in position but you'll have to improvise there.
A lead filled, laminated plastic curve is a great asset. ... -24-Light/
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