Why Is This Sweep Flattening on Two Sides?

[Anonymous]

I have a sweep that is flattening on two sides. It it supposed to be a NATO 40mm Inside Screw. Any ideas?

I am using the coil simply for the pitch and radius of the path.

Thanks

[jeff_strater]

hmm...  that is interesting.  I don't have an immediate answer.  I'll have to check with the modeling kernel team.

[jhackney1972]

Is this the final model you desire?  If it is, then the only thing I did was redefine the complete surface sketch as the sweep profile.  The original file, attached, only used the surface "edge" to sweep.

[jeff_strater]

I cannot speak for @Anonymous , but my interpretation of the question is:  Why is the sweep different on one side of the helix path than the other?

the original showed a different version of the same issue:

[wmhazzard]

Shouldn't sweeping a surface along a path give a solid body? This is ending up as another surface. 

[davebYYPCU · Accepted solution]

That's because he is using parallel and you show see what happens with Perpendicular.

I believe not checked yet, and not time now, 

should be a path and guide surface version.

gotta go.

[jeff_strater]

this sweep was a surface sweep, created with only one edge of the surface, not the whole surface, which is why it results in a surface

[davebYYPCU · Accepted solution]

Yep, Sweep with Rail and Guide Surface, 

Same selections that you have already, Guide surface is the vertical inner face of the solid triangle.

Might help....

(Sorry about prev spelling was already late.)

[jeff_strater]

yes, Dave is correct.  It was late for me, too, and I was not thinking correctly.  Selecting that vertical surface as a guide surface gives what I expect is the correct result:

and I realize that the current result is, as @davebYYPCU said, because "Parallel" is selected.  But, what I don't understand is why "Perpendicular" gives this result:

am I missing some subtle mis-alignment of the profile and the path?

[davebYYPCU]

We had that drama to live through before you introduced the guide surface option.

To do with the plane on a path verses orthographic plane for the profile, and or what’s normal to a helix.

Hah, I was late for an appointment, was lunchtime here at the time, now it’s just late.