How to model a parametric hook?
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How to model a parametric hook?
Hi,
maybe two years ago I tried to model a smooth looking parametric hook, but failed pretty much (because I couldn't find a way to place sketches on the right places). Now using Part Design next, the job can be done within 15 minutes. I like the new Part Design! The new tools like Datum Planes are a huge step forward for FreeCAD.
If you want to see how I designed the hook, follow the link to youtube (be aware, the video is in german):
Edit: I recorded the video again and tried to use your advices. Many thanks to you, I never ever saw a forum which is as helpful than this one!
maybe two years ago I tried to model a smooth looking parametric hook, but failed pretty much (because I couldn't find a way to place sketches on the right places). Now using Part Design next, the job can be done within 15 minutes. I like the new Part Design! The new tools like Datum Planes are a huge step forward for FreeCAD.
If you want to see how I designed the hook, follow the link to youtube (be aware, the video is in german):
Edit: I recorded the video again and tried to use your advices. Many thanks to you, I never ever saw a forum which is as helpful than this one!
Last edited by Christoph on Sat Apr 21, 2018 1:32 pm, edited 1 time in total.
Re: How to model a parametric hook?
Nice video. In the first three minutes you don't need the construction lines. In 0.17 you can apply horizontal constraints directly to points. A serious problem can be the symmetry constraint. It might work - as it apparently does here - but it often leads to problems. Your Sketch is overconstrained because the symmetry implies the horizontal constraint.
More later, I'm short of time now.
More later, I'm short of time now.
A Sketcher Lecture with in-depth information is available in English, auf Deutsch, en français, en español.
Re: How to model a parametric hook?
Heads up: You can use the [video] tags to display videos
Nice job, btw.
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Want to contribute back to FC? Checkout:
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Re: How to model a parametric hook?
I have seen the rest and I am pleased by the usage of the datum planes as sections. I hope we will see more of your videos!
A final remark: The first datum plane is in fact the XY plane so you could omit it without any loss.
A final remark: The first datum plane is in fact the XY plane so you could omit it without any loss.
A Sketcher Lecture with in-depth information is available in English, auf Deutsch, en français, en español.
Re: How to model a parametric hook?
Christoph, Thanks for this tutorial. It came at the right time for me - a relatively new user. It am starting to put some of my jewelry designs in FreeCAD and will need to use those techniques. Tom Meyers
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Re: How to model a parametric hook?
Hi Christoph,
thank you very much, that is a nice video tutorial.
Please read this trick to avoid the many segments of the sweep-surface:
https://forum.freecadweb.org/viewtopic. ... 73#p180473
Concerning fillets, it's not needed to select so many edges if it's a tangent curve, one edge will do the job.
https://forum.freecadweb.org/viewtopic. ... 19#p198819
The helper sketcher lines are not needed, because there is another method to create the datum planes, please check my animation: Please have a look at the zebra-tool inside the curves- and nurbs-workbench:
https://forum.freecadweb.org/viewtopic. ... 87#p204587
Best regards
Wilfried
thank you very much, that is a nice video tutorial.
Please read this trick to avoid the many segments of the sweep-surface:
https://forum.freecadweb.org/viewtopic. ... 73#p180473
Concerning fillets, it's not needed to select so many edges if it's a tangent curve, one edge will do the job.
https://forum.freecadweb.org/viewtopic. ... 19#p198819
The helper sketcher lines are not needed, because there is another method to create the datum planes, please check my animation: Please have a look at the zebra-tool inside the curves- and nurbs-workbench:
https://forum.freecadweb.org/viewtopic. ... 87#p204587
Best regards
Wilfried
Re: How to model a parametric hook?
Hi,
thank you all for your feedback! Today I tried your advices, and the workflow is now much faster. Especially the orientation of the Datum Planes as advices from Wilfried lift the process up to a higher level. Only the conversion of the sweep sketch into a b-spline didn't work out, the sketch get always broken. Wilfried, do you have a solution for that?
I attach the file with the broken sweep sketch.
To avoid spreading working methods which are not ideal, I decided to record the video again (probably next weekend).
Regards
Christoph
OS: Windows 10
Word size of OS: 64-bit
Word size of FreeCAD: 64-bit
Version: 0.18.13532 (Git)
Build type: Release
Branch: master
Hash: 4adeb7702da610da2c7f3014217044167109f0d6
Python version: 2.7.14
Qt version: 4.8.7
Coin version: 4.0.0a
OCC version: 7.2.0
Locale: German/Germany (de_DE)
thank you all for your feedback! Today I tried your advices, and the workflow is now much faster. Especially the orientation of the Datum Planes as advices from Wilfried lift the process up to a higher level. Only the conversion of the sweep sketch into a b-spline didn't work out, the sketch get always broken. Wilfried, do you have a solution for that?
I attach the file with the broken sweep sketch.
To avoid spreading working methods which are not ideal, I decided to record the video again (probably next weekend).
Regards
Christoph
OS: Windows 10
Word size of OS: 64-bit
Word size of FreeCAD: 64-bit
Version: 0.18.13532 (Git)
Build type: Release
Branch: master
Hash: 4adeb7702da610da2c7f3014217044167109f0d6
Python version: 2.7.14
Qt version: 4.8.7
Coin version: 4.0.0a
OCC version: 7.2.0
Locale: German/Germany (de_DE)
- Attachments
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- Hook_sketch_broken.FCStd
- (22.14 KiB) Downloaded 84 times
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- convert into bspline.JPG (126.91 KiB) Viewed 3561 times
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Re: How to model a parametric hook?
I'm glad that I could help you with the datum-planes.Christoph wrote: ↑Mon Apr 16, 2018 6:46 pm Hi,
thank you all for your feedback! Today I tried your advices, and the workflow is now much faster. Especially the orientation of the Datum Planes as advices from Wilfried lift the process up to a higher level. Only the conversion of the sweep sketch into a b-spline didn't work out, the sketch get always broken. Wilfried, do you have a solution for
Concerning the "convert given geometry to b-spline" tool, for me it seems that this tool is broken / has a bug.
I remember some cases with that tool in past, it worked like a charme.
But there is another great tool inside the curves workbench. It can convert a bunch of curves into one bspline curve.
Please let me show you a short demo: Please care about the data-tab, there is an option "corner-break", change into false.
Please try this trick on the crane hook for the sweep-profiles, and you will see a great result with a smooth surface.
Best regards
Wilfried
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- Veteran
- Posts: 7791
- Joined: Tue Jan 07, 2014 11:10 am
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Re: How to model a parametric hook?
Here you can see the difference.
1. conventional sweep: 2. smooth sweep:
1. conventional sweep: 2. smooth sweep: