AutoCAD 2007/2008/2009 DWG Format

[#1]

hi, hope someone can help me out here:

i'm trying to help a freind who needs a 3d model of their acoustic guitar to put it through testing for a research project.

my plan was to draw out the profile of the guitar top, Extrude it to create a solid, then Shell it to 3-4mm thick.

i have drawn the top as a polyline, as a spline and as individual arcs, here's what it lookes like:

but i cant seem to extrude this as a solid.

Am i going about this the wrong way? should i create a solid cuboid of the right thinkness, then somehow use the outline to 'cut' the shape into the solid block?

any help or advice would be appreciated.

as an aside, heres roughly how it's looking in sketchup, which is the final type of shape i'm aiming at.

[#2]

Attach your drawing (.dwg) here.

Let's have a look.

[#3]

here we go, dwg attached with the same shape as a Spline, Pline & arcs...

thanks for the help

[#4 · Accepted solution]

I didn't do what you want because of the overlapped near the neck.

[#5]

I didn't look at the file, but you would use Presspull rather than Extrude if you have good geometry.

[#6]

Thank you!

i just had a chance to take another look at this, and there was a tiny wee overlapping line. when sorted, the solid came up no problemo!

thanks for that.

as the model progresses (it might get a wee bit complicated with complex shapes in some areas), i might be back with another question or two

[#7]

Hello again! after an extended hiatus, I'm back on this task (unpaid, and for the love of trying something new only!)

so, if I was 3D modelling a standard flat backed, flat-topped acoustic guitar, it would be simple enough and I wouldnt have any questions, but life is never simple it seems.

this guitar is pretty unusual as the manufacturer is doing some interesting stuff with carbon fibre, which allows much more freedom for shaping than wood - I therefor have something quite difficult to model!

here is the guitar model, with some pics to give you an idea http://www.emeraldguitars.com/products/guitars/x10/

I would really like to check that my anticipated sequence of actions for modelling it is sensible.

I planned to loft, carve, push pull and otherwise cajole the main shape out of a 3d solid, then 'shell' the model, then cut out the soundhole and add the bridge & neck by 'union'.

first thing i have done is measure the guitar, I have used traced photos combined with physical measurements to get a polyline for the edge of the top, for the edge of the back, for what I judge to be the edge of the bulbous section on the back.

I have carried out a 'loft' to form a 3d solid between the edge of the top and the edge of the back

here's an image of the lofted solid between the two main edges

however, I am unsure as to how I go about modelling the radiussed top of the guitar. It's not a constant radius, it flattens in the middle. In my mind I am thinking of how they make architectural plaster mouldings, you start with too much material and pull a profiled blade across, and the section is scraped away. I imaging drawing a polyline of the profile I want and dragging it across. Or do I construct a box above, draw the profile on the end and extrude, then do a 'subtract' command?

any advice would be great, how would you go about modelling this stage?

next up, the bulbous back....

[#8]

just a little update, since my waffling about forming the curve to the top was perhaps unclear

I constructed a negative of the curve, which I hope to 'subtract' from the body. image is of the negative hovering above...

[#9]

using subtract really worked well!

before I go on to try and model the bulge on the back, radius the edges etc, I wanted to do a test 'shell' command, and I've hit a snag: 'no solution for a vertex' error... the solid has been checked and seems OK, looking on forums one thing to try seems to be to move the model closer to the origin, which I have done and it made no difference.

Any ideas? too complex a shape?