Odd sweep result?

Post here for help on using FreeCAD's graphical user interface (GUI).
Forum rules
and Helpful information
IMPORTANT: Please click here and read this first, before asking for help

Also, be nice to others! Read the FreeCAD code of conduct!
User avatar
Mongrel_Shark
Posts: 133
Joined: Sat Oct 15, 2016 9:54 am
Location: Australia

Odd sweep result?

Postby Mongrel_Shark » Wed Nov 16, 2016 5:14 am

I am trying to make a handle for 3D printing.
I tried to use the part Sweep tool
It did some extra curves I didn't want.
Hopefully deleting the sweep in the attached file will make it clear what I was trying to achieve.
I was hoping for a gentle bulge in the middle rather than an hourglass....
I originally had less sketches through the middle part but it was not playing nice and adding more sketches improved things a little, I think :?
What did I do wrong? Or should I be approaching this another way?

OS: Ubuntu 14.04.5 LTS
Word size of OS: 64-bit
Word size of FreeCAD: 64-bit
Version: 0.16.6703 (Git)
Build type: None
Branch: releases/FreeCAD-0-16
Hash: 2ce5c8d2e3020d05005ed71f710e09e9aa561f40
Python version: 2.7.6
Qt version: 4.8.6
Coin version: 4.0.0a
OCC version: 6.8.0.oce-0.17
Handle.fcstd
(30.05 KiB) Downloaded 12 times
User avatar
Mongrel_Shark
Posts: 133
Joined: Sat Oct 15, 2016 9:54 am
Location: Australia

Re: Odd sweep result?

Postby Mongrel_Shark » Wed Nov 16, 2016 5:24 am

Nevermind.
Worked it out. 2 sweeps not 1...
handle V2.fcstd
(31.37 KiB) Downloaded 18 times
User avatar
NormandC
Posts: 18534
Joined: Sat Feb 06, 2010 9:52 pm
Location: Québec, Canada

Re: Odd sweep result?

Postby NormandC » Wed Nov 16, 2016 5:39 am

Check the joint between your two sweeps, the ends don't match. That's because the bottom point of the upper line in Sketch is lower than the Z height of Sketch006.

In this case you can use Part Loft instead as it does not need a path.
Attachments
handle V2_normandc1.fcstd
(48.75 KiB) Downloaded 15 times
User avatar
microelly2
Posts: 4553
Joined: Tue Nov 12, 2013 4:06 pm
Contact:

Re: Odd sweep result?

Postby microelly2 » Wed Nov 16, 2016 6:36 am

You can add some more frames to get more tangent control
See picture story here http://freecadbuch.de/doku.php?id=blog: ... _the_sweep
I have to look for the script for my example and will post it next. ;)
User avatar
Mongrel_Shark
Posts: 133
Joined: Sat Oct 15, 2016 9:54 am
Location: Australia

Re: Odd sweep result?

Postby Mongrel_Shark » Wed Nov 16, 2016 8:17 pm

I tried to print my handle and it was clear there where a few problems.

A. It was too big.
B. it was a very difficult print that was going to need a ton of support structure no matter which way I printed it. So I am now working on making the 2 loft/sweep parts separate and I will attach them post printing. I also made some flat sides so it can print with no support and less infill.
C. As Norman pointed out some bits didn't line up well.
D. I remembered I also wanted a 15deg inclination on it. Which raised another question.
Can I anchor sketches in one plane (X-Y) to another sketch in another plane (Y-Z) so that if I want to change the angle later I can do so easily?

For the latest version I added construction lines and just eyballed them onto my 15deg line left over from when I was sweeping it.. Would be nice to have it more parametric though.
Handlev5lower.fcstd
(14.2 KiB) Downloaded 12 times
User avatar
Mongrel_Shark
Posts: 133
Joined: Sat Oct 15, 2016 9:54 am
Location: Australia

Re: Odd sweep result?

Postby Mongrel_Shark » Wed Nov 16, 2016 8:19 pm

microelly2 wrote:You can add some more frames to get more tangent control
See picture story here http://freecadbuch.de/doku.php?id=blog: ... _the_sweep
I have to look for the script for my example and will post it next. ;)
Thats a great pictorial. Once I get the basic dimensions sorted I might try to add finger grips using that method :)