how to sweep oblique path?

[shredator]

newbie question - If I want to sweep a sketch along a path that is not already drawn perfectly perpendicular to the sketch, Is there a way to tell the sweep tool to always sweep the sketch along its perpendicular axis?

I'm using 0.16 rev 6405

[jmaustpc]

newbie question - If I want to sweep a sketch along a path that is not already drawn perfectly perpendicular to the sketch, Is there a way to tell the sweep tool to always sweep the sketch along its perpendicular axis?

I'm using 0.16 rev 6405

Hi
yes, don't use Part Sweep, use a different more appropriate tool. Which one depends on what exactly you are trying to do.

Sweep is intended to follow a path, if your path is a simple "normal" to the sketch plane then just PartDesign Pad or Part Extrude, if you have only one profile. If you have more than one profile then use Part Loft.

[DeepSOIC]

There is a trick. You can use Draft PathArray to make planes perfectly perpendicular to the path, and then attach sketches to these planes.

sketch-attachment-to-path-again.FCStd

(6.29 KiB) Downloaded 73 times

[shredator]

Draft_PathArray button doesnt work for me unfortunately. It gives a brief error message at the bottom of the screen (would be nice if the error would come up in the command line) and does nothing.

also, how does this method handle updates? do the planes stay perpendicular to the path when the path is moved?

many thanks for the help so far!

[NormandC]

would be nice if the error would come up in the command line

Edit -> Preferences / General / Output window
Check both "redirect internal python..."
And activate Report view display from Views --> Panels

[shredator]

here's what it gives me:

Code: Select all

Running the Python command 'Draft_PathArray' failed:
Traceback (most recent call last):
  File "C:\Users\user\Desktop\FreeCAD_0.16.6405_x64_dev_bin\Mod\Draft\DraftTools.py", line 4174, in Activated
    self.proceed()
  File "C:\Users\user\Desktop\FreeCAD_0.16.6405_x64_dev_bin\Mod\Draft\DraftTools.py", line 4182, in proceed
    path = sel[1].Object

list index out of range

[DeepSOIC]

You should select the Object, the Path, and then click the patharray button. The error is because it is trying to access the path as second selection, which is probably lacking.

[shredator]

ah ha. that was the problem. be nice if the command actually told you that it was expecting something instead of just dumping some cryptic error.

Anyway, so Im able to array along a path now. I still havent grasped how it helps me align a plane to the path however. I can only get it to align the edge of the sketch with the path. pretty much the opposite of what i want.

side rant: I cant think of an instance where you would want to sweep a sketch and *not* have it kept perpendicular to the path it was being swept upon. how is this current sweep tool useful at all?

@jmaustpc: Tried padding the sketch to make a tube, then rotating the tube. seems like this would work ok, except the pad cannot be rotated because its placement is readonly. using the loft tool doesnt seem relevant to what I'm trynig to do. but maybe i should clarify more.

My overall goal is to design a 3d truss made out of tubing. I thought that I should be able to make the truss using lines, and then somehow sweep a sketch of the tubing walls over all of the elements. Am I just approaching this completely wrong?

sorry for being difficult, thanks very much for all of the help so far!

[sgrogan]

@jmaustpc: Tried padding the sketch to make a tube, then rotating the tube. seems like this would work ok, except the pad cannot be rotated because its placement is read-only. using the loft tool doesn't seem relevant to what I'm trying to do. but maybe i should clarify more.

This is due to the the intended part design linear workflow, which is features applied on top of previous features. So you need to change the placement of the very first sketch, in your case just the sketch that the initial pad is based on.

The Arch_Frame may be of interest.

[jmaustpc]

Anyway, so Im able to array along a path now. I still havent grasped how it helps me align a plane to the path however. I can only get it to align the edge of the sketch with the path. pretty much the opposite of what i want.

The problem is that your first post was so ambiguous that we have all interpreted what you want differently.

Draft workbench has Array tools that create an Array of copies of a solid. Polar and ortho Arrays but also Path Array which instead of making the array in an either circular or rectangular pattern, it makes the array by following a path which can curve and bend and go all over the place. A work around/trick is that Path Array controls the orientation of the solids relative to the path at the exact location of each new cloned solid.

side rant: I cant think of an instance where you would want to sweep a sketch and *not* have it kept perpendicular to the path it was being swept upon. how is this current sweep tool useful at all?

the tool is great, there are cases where you want to control the orientation,

My overall goal is to design a 3d truss made out of tubing. I thought that I should be able to make the truss using lines, and then somehow sweep a sketch of the tubing walls over all of the elements. Am I just approaching this completely wrong?

can you provide any pictures, links or some sort of example? If so we could likely suggest some alternatives.

Also it is possible that your project may become slow to compute if it is rather complex. You should consider if some details need to be modelled at all or if you are better to make a more simple model and then just specify some details by a materials or other description. For example you would normally not model threads, not model the pattern of checker plate flooring etc. It is also possible that you may not really need to model tube, you can sometimes just use a cylindrical solid and just specify that the material is XYZ tubing. But all this depends on exactly what and why you are modelling something.

Jim