Compound Radius Fretboard

[gordread]

Hey all, I know that this topic has been discussed. I found items going back a few years. The best one is:
http://forum.vectric.com/viewtopic.php? ... +fretboard

But it never actually mentions how to build a fretboard with a compound radius. Essentially a rectangular block with a radius of 12" at one end nice and seamlessly blending into a 16" radius curve at the other.

The pictures in the previous discussion describe well what I'm trying to do, but I've not been able to figure out how to do so.

I can easily get a single curvature fretboard by using a two rail sweep of the section of a circle between two straight vectors. What I can't figure out is how to use a section of 16" radius and 12" radius make the neck into a compound radius component.

I have recently upgraded to Aspire 10.5.

Any thoughts or tricks would be greatly appreciated.

I will try to attach my file for reference. It has the radii and the fretboard vectors.

Gordon

[gordread]

I upgraded to version 10.0, obviously not 10.5. It was late when I wrote the previous post. sigh.

[TReischl]

Gord, you just draw the vectors as you see in the picture in the post you referenced.

Two rails.

Then draw the two radii. The software takes care of the blending between them as the radius moves down the rails.

That is actually about as simple as it gets when doing two rail sweeps.

What I do is play around with things when I am not sure how they work. I figured out a long time ago that my computer will not explode no matter what I do to it,

Give it a go, play around with the options in the two rail sweep panel and check the results.

I cannot load your file because I am one of those folks who only upgrades once in a blue moon. And the blue moon has not arrived yet.

[litzluth]

A few things.
First, the radii need to be mirrored horizontal so the fretboard humps up, not down.
Second, if you sweep with a trapezoidal shape, I think the radius will be wierd. So I extended the bottom vector to create a rectangle to sweep. If you want the trapezoid shape, you can just create some profile vectors to cut that.
The sweep itself is straightforward. You first select the rails, then select the cross sections in order. The 12" radius at the nut, the 16" radius at the end towards the bridge.

[litzluth]

For some reason the forum board isn't letting me upload the revised file

[Jim_in_PA]

The process "merely" involves modeling with a profile of x radius at the headstock and y radius at the heel end. IE, two profiles and two rails. The software will calculate the change over the length of the fretboard as it transitions from the tighter radius at the headstock to the flatter radius at the heel.

[gordread]

Thanks everyone. I guess I didn't play around with the two rail sweep tool enough. I've only ever used it to sweep one profile along two rails, not using two different profiles.

I will have to try it out when I get home tonight.

Gordon