Hi there,

I hope this is the right place for this topic. While trying to work with the sweeptool, I cant get the desired result. Though I have both starting points centered
I cant get it the sweep along the rail to where I want it :see my blue overpaint. I tried all kind of different adjustments. What am I possibly doing wrong?

Thanks for any advise where to ask and how to get up and running. Yes, I watched some of the beginnerstuts. and I am on MoI 4

Best Jake

Better to post your 3dm file!

Maybe best to use the NetWork for this sort of curves...
(planar for the sides volumes)

ok. I have tried this before, but didn`t get the desired result so i went for simplification path trying to do one half first and then merge it with the other half.

here is my file. Ok. cant attach here, so I will try at my first post.

Your example looks so effortless, but which is the shape and what are the rails?

Network don't need rails : all are just cuves in any order!
better if they snap on their path
That makes a surface
Here the Planar sides (of course just draw a vertical segment before the "Planar" ) close the volume: so just "Join" all or "Boolean Union" for obtain a "Solid"

ah, i see different tool, I will try this thank you very much!

Seems You have no problem with this Faw nose ?

sorry wrong file

heres the problemfile

I redraw your curves...as you can see all curves are "trimed" for each "patch"
All are "snaped" each other

Thats what I want to achieve. though there is some strange irragularity on the right side ahh thats from my doubled spline probably
I will try to replicate it tomorrow with the network toll...Thanks a lot!

Jake –

You can also experiment using Loft to make this nose cone.

I arranged your curves as below. First, I ran the “Rebuild” command to lower and simplify the point count.

Next I trimmed the base into two parts, orange and red. The two curves must meet at a single point.

Next I made the blue profile curve as a single curve. The ends must touch the base curves where they meet.

The only tricky part to this Loft arrangement is how you pick the curves:

• Select the red and orange base curves simultaneously (not one at a time). *
• Select the blue profile curve.
• Loft using Normal / Auto settings.

* An alternate way to select the curves is to select all 3 at once, deselect the blue curve, then re-select the blue curve.

Ed Ferguson

Hi jake, so for original question on why sweep is not working well there - the way one rail sweep works is it moves the profile along the rail rotating it by the rail curve's tangent direction. You can get a kind of preview of what that is doing if you use Transform > Array > Curve on your profile, which will generate this:





So notice there how the sections are bunching up and crossing over each other there? That's what is making a poor quality surface result.

For one-rail sweep it's kind of a tube-like construction mechanism where you can't have a profile curve go off by a larger distance than the radius of the bend, otherwise sections will bunch up as shown above.

Instead of the profile curve rotating with the curve tangent, you would instead need it to pivot around its own endpoints. I want to make that kind of pivot an option for sweep in the future but there is a fairly similar command now called rail revolve, under Construct > Revolve. It allows for one profile curve, one rail curve and then also a revolve axis. The profile will pivot around the revolve axis while scaling out to meet the rail. So since it has a pivoting action it could work for this kind of case.

Anyway hope that helps explain what you were running into originally.

- Michael