Official Luthiers Forum!

Hi all,

Struggling with surfacing in solid works, I've been working on a model of an SG for a couple of months now but just can't seem to get it right.
I was hesitant to post as i really wanted to be able to do it by myself, but after many failing attempts i thought someone may be able to shed some light on where i'm going wrong

so the closest have been able to get is by doing the following process:

1. Sketch the body shape and extrude (35mm)
2. Draw the inside profiles
3. Create plane 25mm below the front plane
4. Draw the outside profile on the above plane (combination of offset entities and spline sketches)
5. Connect profiles by drawing straight guide curves between the two
6. Create a surface loft using the profiles and guide curves
7. Cut surface using loft
8. Hide surface to show the created surface

To me it just doesn't look right and i'm wondering whether i'm using the right design flow and if there is another way i should be doing it?
when looking from the top view the carve is all over the place not a smooth regular surface.

I've attached a few pics just in case i have lost anybody! i did have a fully completed model which was a close as i could get it using the above method but the Wife accidentally deleted it... after 2 months work!! i now save my files on the PC and back up drive!

any guidance would be greatly appreciated!
Cheers
Glenn

I'm no expert either but here's a thought for you: SG bodies are made with shapers, almost certainly without any Z control. Instead of using a loft to make your chamfer, what about making a sketch with a 45 degree angle and using a sweep/cut to crate them? The challenging part would be to make a guide curve that brings the profile in contact at the right points.

Basically, I'm thinking that you use the sketch like Gibson uses the shaper in the actual production of the body.

Edit: If you want to continue to use the loft, I would make a guide curve on the edge of the profile that follows the contour you need. You could do it by making a sketch of split line on a plane orthogonal to the "top view" of the guitar and projecting it on the side (does that work with extruded solids?)

_________________
http://www.birkonium.com CNC Products for Luthiers
http://banduramaker.blogspot.com

Yep, what he said.

Sometimes the easiest way to model something in 3D is to imitate the way it's machined. In this case, you make your 'shaper cutter' and the sweep it along a rail to get your cut.

_________________
Bob Garrish
Former Canonized Purveyor of Fine CNC Luthier Services

SG's are so easy - I could bevel them in 10 minutes flat with a rasp and scraper.
CNC the basic outline and route the pockets if you want.
The only thing easier would be like a Gibson L6-S.

_________________
"Act your age, not your shoe size" - Prince

Thanks Guys! That makes perfect sense i'll give it a shot.

Chris, yes definitely an easy guitar and would be much faster using a rasp, this it not something i'm going to cnc, i'm just trying to sharpen my modeling skills.

Thanks again
Glenn

One more thing - I have an SG bass and just took a look at it, the angle looks closer to 60/30 (depending where you're measuring from) rather than 45. I'm of course assuming that the guitar body is very similar. If you need, I can measure it.

_________________
http://www.birkonium.com CNC Products for Luthiers
http://banduramaker.blogspot.com

thanks Andy appreciate it, i'll let you know how it goes.
cheers
Glenn

Ok so I tried it out using the cut-sweep feature and it definitely worked a lot better, much cleaner, hopefully i'm on the same page as the suggestions.

Going by the top view its still appears a bit wavy and not the smoothest line, as noted by Andy i think i'll need to work on the guide curve (in this case i thought it was best to use the 'inner' guide curve) i think thats what would be causing the wavy line. I guess this is because the inner guide curve is slightly different to the outer guitar shape so the outside depth varies slightly.

Anyway i'll keep working at it and see how it goes feels like i'm on the right track.

Thanks
Glenn