Sketcher tutorial

A place to share learning material: written tutorials, videos, etc.
Forum rules
Be nice to others! Respect the FreeCAD code of conduct!
User avatar
MSOlsen65
Posts: 226
Joined: Wed Feb 19, 2020 8:30 pm
Location: Winnipeg, MB Canada
Contact:

Re: Sketcher tutorial new version is now Sketcher Lecture

Post by MSOlsen65 »

chrisb wrote: Thu Mar 26, 2020 7:16 pm Dear Friends of FreeCAD, I finally did it... "A Sketcher Lecture" ...Please tell me nevertheless if you find errors.
Well Chrisb, I just finished yoir newest "Master Piece", and it is positively BRILLIANT :D Well done!
Sincerely,


Michael S. Olsen
Electrical Engineer & Joiner
chrisb
Veteran
Posts: 53951
Joined: Tue Mar 17, 2015 9:14 am

Re: Sketcher tutorial

Post by chrisb »

Thanks! And thanks for helping!
A Sketcher Lecture with in-depth information is available in English, auf Deutsch, en français, en español.
Dazs
Posts: 2
Joined: Wed Mar 25, 2020 3:20 am

Re: Sketcher tutorial

Post by Dazs »

I am just getting started with FreeCAD and with the Sketcher workbench and your tutorial. Thank you for all the work you have put into this. On a first note: did you intent to have these red outlined boxes in your pdf file? See picture
Attachments
sketcher tutorial content outline.jpg
sketcher tutorial content outline.jpg (76.91 KiB) Viewed 2189 times
User avatar
PrzemoF
Veteran
Posts: 3520
Joined: Fri Jul 25, 2014 4:52 pm
Contact:

Re: Sketcher tutorial

Post by PrzemoF »

Welcome to the forum!

Those are links in pdf file. You can switch the red boxes off in the options if your pdf viewer.
openBrain
Veteran
Posts: 9034
Joined: Fri Nov 09, 2018 5:38 pm
Contact:

Re: Sketcher tutorial

Post by openBrain »

Dazs wrote: Sun Mar 29, 2020 4:14 pm I am just getting started with FreeCAD and with the Sketcher workbench and your tutorial. Thank you for all the work you have put into this. On a first note: did you intent to have these red outlined boxes in your pdf file? See picture
This is how Okular (and maybe other viewers) display internal hyperlinks. You can customize this in the viewer. It's not part of the document. ;)
Dazs
Posts: 2
Joined: Wed Mar 25, 2020 3:20 am

Re: Sketcher tutorial

Post by Dazs »

thank you guys for the help and input. I appreciate the quick replies.
User avatar
jruiz
Posts: 479
Joined: Tue Oct 28, 2014 1:07 pm
Contact:

Re: Sketcher tutorial new version is now Sketcher Lecture

Post by jruiz »

chrisb wrote: Thu Mar 26, 2020 7:16 pm Dear Friends of FreeCAD, I finally did it. I have uploaded a new version of the formerly called Sketcher tutorial. I have renamed it to the more appropriate title "A Sketcher Lecture" but it is basically the same contents. But only basically: I have updated quite some details to 0.19 and I have included allmost all remarks of openBrain - which was a huge load - and MSOlsen65, which was a lot too. Thus it has slightly grown in size, although some sections could be shortened due to an improved workflow in 0.19.
Please tell me nevertheless if you find errors.

Edit: the old linkis no longer working, use https://owncloud.gwdg.de/index.php/s/eZ ... 9/download
Great job. Congratulations.
As FreeCAD is so parametric, I was wondering if you, as the father of "A Sketcher Lecture", could start a new topic, or maybe use this one, for collecting users experiences, tips and hints for trying to establish in some way rudiments on the art of setting sketch robustness. Of course, considering that in general there may be a compromise between robustness and computational effort. Then add (maybe) a chapter to "A Sketcher Lecture" considering this topic.
Congrats again.
I have uploaded many FreeCAD video tutorials to my YouTube channel
chrisb
Veteran
Posts: 53951
Joined: Tue Mar 17, 2015 9:14 am

Re: Sketcher tutorial

Post by chrisb »

Thanks for the compliment. You may well create such a topic yourself and elaborate what exactly you mean. I'm not sure what you mean by robustness, do you mean flipping sketches or sketches in the light of topological naming issues? Both seem to be independent from computational effort, which is mostly driven by the number of constraints, perhaps by the number of DOF consumed by constraints, i.e. a point-to-point tangency would take three times the effort of a vertical constraint.
A Sketcher Lecture with in-depth information is available in English, auf Deutsch, en français, en español.
User avatar
jruiz
Posts: 479
Joined: Tue Oct 28, 2014 1:07 pm
Contact:

Re: Sketcher tutorial

Post by jruiz »

chrisb wrote: Fri Apr 10, 2020 8:03 am Thanks for the compliment. You may well create such a topic yourself and elaborate what exactly you mean. I'm not sure what you mean by robustness, do you mean flipping sketches or sketches in the light of topological naming issues? Both seem to be independent from computational effort, which is mostly driven by the number of constraints, perhaps by the number of DOF consumed by constraints, i.e. a point-to-point tangency would take three times the effort of a vertical constraint.
Suppose a sketch depending on n parameters is fully constrained according to the solver. As we know, what we get is (in general) one of the (many) local solutions the sketch has subject to the imposed constraints. In this context, what I mean with robustness, is that if any of the n parameter(s) of the sketch is varied by a "non-small" (finite, non-infinitesimal ) quantity, the "form" (or the "structure") of the sketch keep unaltered.
I have uploaded many FreeCAD video tutorials to my YouTube channel
User avatar
MSOlsen65
Posts: 226
Joined: Wed Feb 19, 2020 8:30 pm
Location: Winnipeg, MB Canada
Contact:

Re: Sketcher tutorial

Post by MSOlsen65 »

jruiz wrote: Fri Apr 10, 2020 2:40 pm Suppose a sketch depending on n parameters is fully constrained according to the solver. As we know, what we get is (in general) one of the (many) local solutions the sketch has subject to the imposed constraints. In this context, what I mean with robustness, is that if any of the n parameter(s) of the sketch is varied by a "non-small" (finite, non-infinitesimal ) quantity, the "form" (or the "structure") of the sketch keep unaltered.
I would think that the answer to such a case would vary widely in scope depending on both the broader design and the complexity of the sketch. That said, my first thought about the sketch, and possibly the design as well, is to consider simplification by reduction (i.e. use several simpler sketches instead of a single complex one). Generally, the simpler the sketch, the broader its effective range of variance without distortion is for a given local solution. While this will create a larger number of pad, pockets, etc., following the good practices of using construction datum and shapebinders, should in theory result in a far more robust design.

Assuming I have correctly understood Chris' brilliant tutorial. ;)
Sincerely,


Michael S. Olsen
Electrical Engineer & Joiner
Post Reply