Adding Parametrically Controlled Curve in Two Directions to a Body

[Anonymous]

I am trying to use Fusion 360 for some acoustic guitar components. To learn I started by modelling the components of a guitar in Fusion 360, and kept it so that I could update the parameters and change dimensions etc. However, as I am new to Fusion 360, to keep things simple I kept the top and back of the guitar flat, when, in reality they are curved. This is the step I need help with.

I may well be wrong with this, but the approach I’m imagining is:

• Sketch guitar outline
• Push/Pull to create body (up to this point it’s the same for a flat top)
• At a defined distance from the top of the guitar (e.g. 325mm) and along the centreline, pull the guitar top upwards (without changing the thickness of the body) to add a curve to the body in both the up-down and side-side direction.

Using the Conical Curve tool, and then intersecting this with the guitar top body I have created a parametrically controlled curve but only in the up-down direction. I have exaggerated the curve for the purpose of the screenshot below, but as you can see I also need to control the curve in the side-side direction. Essentially all the edges of the guitar body must remain on the same plane.

I don’t want to actually make the top/soundboard using CNC. However, it is vital to get it modelled correctly so that other components (e.g. braces, slipper of the neck) that I do wish to CNC will be made accurately.

Thanks

[etfrench]

First, see Rule#1

Dimensions will only work on one plane, but you can use formulas in User Parameters to link dimensions.

You may need to post your file to get more detailed help.

[Anonymous]

Thanks for the response, and sorry for the delay in providing further information.

I’ve attached a file – although it’s very basic:

• Created ‘Soundboard’ component.
• Added Sketch ‘Outline’ and mirrored my design along a construction centre line.
• Used Push/Pull command to create a 2mm thick body also called ‘Soundboard’.

What I am now trying to achieve is some form of deformation of the top, but in multiple planes:

• Specify a single point along the centre line of the body, e.g. 325mm down from the top.
• At this point define a distance by which to ‘pull’ that point outwards, e.g. 3mm.
• The edge/extremities of the body should remain on the existing plane.
• In effect the body deforms to add both a top/bottom curve and a side/side curve, with the curve defined by the edges of the existing body and the location and ‘pull’ distance of the specific point along the centre line.
• The thickness of the body should remain unchanged, in this example 2mm.

I've seen tutorials on creating carved top guitars, but I'm hoping that this is considerably simpler as the 3D profile of an arch top guitar is far more complex than the domed top of an acoustic guitar.

Any help would be greatly appreciated.

[davebYYPCU · Accepted solution]

Something like this  - 3mm almost is not noticeable, 

I placed the point where you said, 

Patched the outline and included the point as requested, works a treat, not used it before, but saw another example recently.

thickened the patch by 2mm - section analysis looks good.

file attached

[Anonymous]

Many thanks for this advice.

I used the timeline in your file to workout exactly what you´d done, and, as you said, it worked perfectly.

Although for a guitar I'll only be using the smaller aforementioned dimensions, I also tested it with larger dimensions so I could fully see what was going on. It's much easier to see like that!

Thanks again.