OUT DAMN CUSP!

[moon161]

Crash course in lofting, almost there, but I can't get a cusp out of my surface, it follows the line I noted in the screenshot. SWX won't let me use a guide curve that goes between 2 points on the same profile, which it seems would solve the problem. Any suggestions? Greatly appreciated.

Thanks,

SWX 2010, SP3

 

[moon161]

Oops, screenshot linked.

 

[gwubs]

Those cusps usually occur in a surface when the input is not smoothly possible. Generally, if one profile has sharp corners, and the next fillets, SW will "make it work", but not give the smooth surface you were picturing. I do a lot of surfacing, and the better your linework is, the better your surface. That said, I have also been amazed at how well SW has done on occasion with pretty bad profiles, and guide curves. In surfacing, keep trying different techniques, and make sure your surface is mathematically possible and well defined. Stay with it, and you will find as you gain experience, it gets easier.

 

[moon161]

So you think it's the 90 degree corner too. Back at it.

Thanks.

 

[rollupswx]

I noticed that you have a lot of unconstrained sketches?
Can you attach your sldprt here?
One approach might be to get it all enclosed - then Knit solid.
Then Delete the face(s) and replace with a filled surface and re-knit.

 

[moon161]

I've got a million sketches in there, and half a dozen lofts, each using a couple of the sketches and a few guide curves.

Mostly different iterations in the sketch that goes around the top.

I'll have to model a similar case that represents the same problem to keep it safe.

 

[moon161]

Turned the problem around:
Profiles were the loops around the top and bottom, guide curves connected the two.

Changed it, modeled as a 1/2 section
the lines that were guide curves, made them profiles
used the top and bottom as guide curves, no more cusp.
Made a boundary surface for the fillet that runs out at the end.

 

[KevinDeSmet]

Thread title made me think :

http://www.clevelandleader.com/files/ExorcistPriest.jpg

Certified SolidWorks Professional

 

[moon161]

I was thinking lady macbeth. Last little bit of blood wont come off her hands 'cause it's in her head.

 

[TheTick]

Basically, you are trying to cram too much into a two-section loft. Divide and conquer.

Also, you are using a funky border edge to define your loft. Reconsider whether these are the curves that should actually define the u-v curves of your loft surface. Ideally, you would define a loft larger than you need with tamer u-v contours and then trim.