Part Design Next: sweep

[Brutha]

Hi All,

I'm having a play with part design next, and trying to figure out how things work. One thing I was trying to do was create a sweep - so I need a path to follow, and some way of placing sketches orthogonal to the the path.

I figure I could add perpendicular lines to my sketch at the points I want to create the sketches for the sweep - see my sketch below. But I can't seem to figure out how to create appropriate datum planes - can anyone point me in the right direction?

Thanks!

Brutha

Screen Shot 2016-07-09 at 14.14.36.png (22.4 KiB) Viewed 2618 times

Code: Select all

OS: Mac OS X
Word size of OS: 64-bit
Word size of FreeCAD: 64-bit
Version: 0.17.7607 (Git)
Build type: Release
Branch: (detached from 4d8f338)
Hash: 4d8f338b8d1de52e0a41abbdec88b87c7e13b0c2
Python version: 2.7.11
Qt version: 4.8.7
Coin version: 3.1.3
OCC version: 6.8.0.oce-0.17

[NormandC]

Hello Brutha,

You need to use the "Normal to edge" setting of Datum plane. Then as first selection, pick either of the line or arc at the end. By default it automatically creates a datum plane at the end vertex. So the perpendicular lines you added at both end of your sketch are unnecessary.

The ones in the middle are useful though, here after first selecting the edge along the sweep path, select the vertex of the perpendicular line that crosses the path.

I was first confused by the fact that the created datum planes looked more like datum lines!

FC_017PDN_normaltoedgedatum_01.png (22.51 KiB) Viewed 2591 times

I'm guessing that's because they resize if there's any geometry crossing them. Since there aren't any, they have a Z height of zero. Once you create a sketch on a datum plane and draw some geometry, the datum planes automatically resize.

FC_017PDN_normaltoedgedatum_02.png (28.57 KiB) Viewed 2591 times

The next tricky part is actually making the sweep: attempting to make one results in FreeCAD crashing. A recent forum discussion mentioned the bug and its workaround.

[NormandC]

The next tricky part is actually making the sweep: attempting to make one results in FreeCAD crashing. A recent forum discussion mentioned the bug and its workaround.

I am unable to find the damn topic.

I also wonder if the PartDesign Sweep supports multiple profiles? It doesn't seem like it does.

[freecad-heini-1]

@Brutha,
please check my video:
http://www.dailymotion.com/video/x4jwdoy

The trick is to extrude your sketch in the part workbench. The result are surfaces you can use like datum planes. So you can draw your sketch on it and use the edge as external geometrie to set constraints.

Draw your three or four circles.

Then use the sweep tool. First click the three circles to the right window, then select the whole curve.
Sorry my English is so lala, I'm a German.

[NormandC]

@ freecad-heini-1

Nice video! But this is a work flow using Part Extrude and Sweep on FreeCAD 0.16.670x.

Brutha wants to use the new PartDesign datum planes and Sweep tool that are only found in FreeCAD 0.17.78xx pre-release version.

[Brutha]

Thanks NormandC! Perfect, that was what I was looking for! Interestingly, when I try your file, it crashes on generating the sweep, but the one I made seems to work ok - see attached file.

Like you say, it looks like part design sweep only supports one profile - I wonder if that's intentional?

@freecad-heini-1 - thanks, nice video! As NormandC mentioned though, I was looking to try out the new datum plane and part design sweep functions in 0.17.

Screen Shot 2016-07-10 at 09.09.50.png (150.04 KiB) Viewed 2537 times

[ickby]

Hello guys

The sweep does Support multiple profiles it is just different structured. There is a extra Box in the Combo View for profile changes and one Option there is multiple profiles. Can't remember the exact Name right now.

[Brutha]

Thanks - yes, that works, multi section in the "Transform mode" box does let you have multiple profiles!

Although, it crashes on most examples I've tried - should I raise a bug report?

[Brutha]

So, was needing to do this today, wanting to model the back of a chair.

I couldn't figure it out at first, but after a bit of googling I got it working in the Part module.

Only to notice this post in a tab I had opened but not read....

I must be getting old!!!!!

[drmacro]

Hello guys

The sweep does Support multiple profiles it is just different structured. There is a extra Box in the Combo View for profile changes and one Option there is multiple profiles. Can't remember the exact Name right now.

You mean this:

PartDesignSweepdialog_annot.jpg (31.15 KiB) Viewed 1096 times