V0.19 Benchmarking--2019 Monthly Challenges #1,#2,#3,#4,#5,#6,#7a,#7b
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V0.19 Benchmarking--2019 Monthly Challenges #1,#2,#3,#4,#5,#6,#7a,#7b
Inspired by the YT videos found here https://www.youtube.com/playlist?list=P ... KdnuAJBnYG I have completed some of these examples to show how they may be modeled in FreeCAD using PartDesign workbench, master sketches, and Sketcher > carbon copy. This may help those who may be transitioning to FreeCAD. The descriptions in the captions of the following images assumes that the user is familiar with the PartDesign and Sketcher GUI, knows where to find the required tools, and how to create fully constrained sketches. It is recommended that a new user should be quite familiar with the PartDesign and Sketcher documentation before attempting any models.
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See also: https://forum.freecadweb.org/viewtopic.php?f=36&t=30104 Sketcher Tutorial
Any questions or comments are welcome. Let me know if the detail is too much or too little and I will edit accordingly. If this is helpful I will continue to add a few more examples to this post.
OS: Windows 10 (10.0)
Word size of OS: 64-bit
Word size of FreeCAD: 64-bit
Version: 0.19.22474 (Git)
Build type: Release
Branch: master
Hash: a44f8ffd427fa9b23b1f00dbf62d66cd152cd774
Python version: 3.8.5
Qt version: 5.12.6
Coin version: 4.0.0
OCC version: 7.4.0
Locale: English/United States (en_US)
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See also: https://forum.freecadweb.org/viewtopic.php?f=36&t=30104 Sketcher Tutorial
Any questions or comments are welcome. Let me know if the detail is too much or too little and I will edit accordingly. If this is helpful I will continue to add a few more examples to this post.
OS: Windows 10 (10.0)
Word size of OS: 64-bit
Word size of FreeCAD: 64-bit
Version: 0.19.22474 (Git)
Build type: Release
Branch: master
Hash: a44f8ffd427fa9b23b1f00dbf62d66cd152cd774
Python version: 3.8.5
Qt version: 5.12.6
Coin version: 4.0.0
OCC version: 7.4.0
Locale: English/United States (en_US)
Last edited by ppemawm on Thu Oct 01, 2020 7:16 pm, edited 8 times in total.
"It is a poor workman who blames his tools..."
Re: V0.19 Benchmarking--2019 Monthly Challenges #2
This tubing run is an example of using the PartDesign workbench but without a master sketch. This work process uses something akin to 'direct modeling' and starts with only one sketch of the tube cross-section and creates the tube run (shown in the first image inset) with pads and revolutions. This could also be done with a 3D wire from the Draft workbench and a sweep, but I prefer to stay in one workbench if possible.
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One caveat: this approach of using edges and faces for pads and revolves will necessarily result in a fragile model if any significant changes are made to the tube configuration (add or subtract pads or elbows). Even so, with a bit of experience you can usually avoid this problem. I do a lot of complex tubing runs in assemblies in-context using this method and find it quite flexible to use and tolerant to dimensional changes. The direction of the elbow can follow compound angles with the proper attachment offset.
The Attachment Mode is quite powerful for locating and aligning datums and sketches so it pays to study the documentation carefully, start simple, and practice, practice, practice. It is one of the first FreeCAD critical skills you want to develop along with becoming comfortable with Placement properties.
REF.: https://wiki.freecadweb.org/PartDesign_Line/en, https://wiki.freecadweb.org/Part_Attachment
OS: Windows 10 (10.0)
Word size of OS: 64-bit
Word size of FreeCAD: 64-bit
Version: 0.19.22474 (Git)
Build type: Release
Branch: master
Hash: a44f8ffd427fa9b23b1f00dbf62d66cd152cd774
Python version: 3.8.5
Qt version: 5.12.6
Coin version: 4.0.0
OCC version: 7.4.0
Locale: English/United States (en_US)
.
One caveat: this approach of using edges and faces for pads and revolves will necessarily result in a fragile model if any significant changes are made to the tube configuration (add or subtract pads or elbows). Even so, with a bit of experience you can usually avoid this problem. I do a lot of complex tubing runs in assemblies in-context using this method and find it quite flexible to use and tolerant to dimensional changes. The direction of the elbow can follow compound angles with the proper attachment offset.
The Attachment Mode is quite powerful for locating and aligning datums and sketches so it pays to study the documentation carefully, start simple, and practice, practice, practice. It is one of the first FreeCAD critical skills you want to develop along with becoming comfortable with Placement properties.
REF.: https://wiki.freecadweb.org/PartDesign_Line/en, https://wiki.freecadweb.org/Part_Attachment
OS: Windows 10 (10.0)
Word size of OS: 64-bit
Word size of FreeCAD: 64-bit
Version: 0.19.22474 (Git)
Build type: Release
Branch: master
Hash: a44f8ffd427fa9b23b1f00dbf62d66cd152cd774
Python version: 3.8.5
Qt version: 5.12.6
Coin version: 4.0.0
OCC version: 7.4.0
Locale: English/United States (en_US)
"It is a poor workman who blames his tools..."
Re: V0.19 Benchmarking--2019 Monthly Challenges #3
This example will give some practice making a simple sketch and introduces the MultiTransform tool in PartDesign to take advantage of the object's symmetry as shown in the inset of the first image.
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See also https://wiki.freecadweb.org/PartDesign_MultiTransform
You may notice that my PartDesign toolbars differ from the defaults since I have customized mine with several tools from different workbenches that I use often such as:
Part > mirror (bodies), measure, check geometry, primitives (primarily for helix), (variable) fillet & chamfer
PartDesign > involute gear
Image > create planar image
Draft > array (polar & linear), path array
Plus, several simple macros to toggle transparency, center coordinates and radius of circle, length of line, etc.
You can create your own customized toolbars using Tools > Customize > Toolbars...https://wiki.freecadweb.org/Interface_Customization
OS: Windows 10 (10.0)
Word size of OS: 64-bit
Word size of FreeCAD: 64-bit
Version: 0.19.22474 (Git)
Build type: Release
Branch: master
Hash: a44f8ffd427fa9b23b1f00dbf62d66cd152cd774
Python version: 3.8.5
Qt version: 5.12.6
Coin version: 4.0.0
OCC version: 7.4.0
Locale: English/United States (en_US)
.
See also https://wiki.freecadweb.org/PartDesign_MultiTransform
You may notice that my PartDesign toolbars differ from the defaults since I have customized mine with several tools from different workbenches that I use often such as:
Part > mirror (bodies), measure, check geometry, primitives (primarily for helix), (variable) fillet & chamfer
PartDesign > involute gear
Image > create planar image
Draft > array (polar & linear), path array
Plus, several simple macros to toggle transparency, center coordinates and radius of circle, length of line, etc.
You can create your own customized toolbars using Tools > Customize > Toolbars...https://wiki.freecadweb.org/Interface_Customization
OS: Windows 10 (10.0)
Word size of OS: 64-bit
Word size of FreeCAD: 64-bit
Version: 0.19.22474 (Git)
Build type: Release
Branch: master
Hash: a44f8ffd427fa9b23b1f00dbf62d66cd152cd774
Python version: 3.8.5
Qt version: 5.12.6
Coin version: 4.0.0
OCC version: 7.4.0
Locale: English/United States (en_US)
"It is a poor workman who blames his tools..."
Re: V0.19 Benchmarking--2019 Monthly Challenges #4
This is another example of using symmetry to modelling advantage which demonstrates the power of the MultiTransformation tool.
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It should be noted that a second master sketch could be used to control all of the dimensions in the XY plane and these sketches can be linked with external geometry reference or expressions. Both are topics for a different example.
https://wiki.freecadweb.org/Sketcher_External/en
https://wiki.freecadweb.org/Expressions/en
OS: Windows 10 (10.0)
Word size of OS: 64-bit
Word size of FreeCAD: 64-bit
Version: 0.19.22474 (Git)
Build type: Release
Branch: master
Hash: a44f8ffd427fa9b23b1f00dbf62d66cd152cd774
Python version: 3.8.5
Qt version: 5.12.6
Coin version: 4.0.0
OCC version: 7.4.0
Locale: English/United States (en_US)
.
It should be noted that a second master sketch could be used to control all of the dimensions in the XY plane and these sketches can be linked with external geometry reference or expressions. Both are topics for a different example.
https://wiki.freecadweb.org/Sketcher_External/en
https://wiki.freecadweb.org/Expressions/en
OS: Windows 10 (10.0)
Word size of OS: 64-bit
Word size of FreeCAD: 64-bit
Version: 0.19.22474 (Git)
Build type: Release
Branch: master
Hash: a44f8ffd427fa9b23b1f00dbf62d66cd152cd774
Python version: 3.8.5
Qt version: 5.12.6
Coin version: 4.0.0
OCC version: 7.4.0
Locale: English/United States (en_US)
Last edited by ppemawm on Sun Sep 27, 2020 3:15 pm, edited 1 time in total.
"It is a poor workman who blames his tools..."
Re: V0.19 Benchmarking--2019 Monthly Challenges #1,#2,#3,#4
Thank you ppemawm for an excellent thread.
I am following first exercise as part of my "conversion to FreeCAD".
All this business of creating copy sketch for every feature is very convoluted especially for someone used to commercial CAD systems.
I guess this is the best way of doing it in FreeCAD?
My eventual aim is to get to Assembly 4, following your other threads on this subject.
But it will take fair bit of adjusting my thinking, to get used to FreeCAD ways
The descriptions of what you were doing to get the end result were just about right - I have managed to get to the end of exercise 1 (eventually )
Had some problems with the tab when I tried something slightly different to your sketch, but worked OK when I followed you exactly - will need to understand why, so that in future I know what I am doing (hopefully)
Still trying to make master sketch invisible on the screen of finished design? toggling visibility doesn't seem to be doing the trick...
Re: V0.19 Benchmarking--2019 Monthly Challenges #1,#2,#3,#4
Thank you for your comments.
Not necessarily. It is only one of several ways, it depends on your objective. It may not be the best in all situations, but it has proven itself to me for top-down design work of complex bodies or assemblies. When you design a complex assembly that has 1000's of sketches you will appreciate the gain in sketch productivity of using the carbon copy where appropriate. If you do not use a carbon copy then you have to use external references or shapebinders if you want to stay parametric with the master sketch, which are fine, but they both require more sketch work.
Good to hear. I am limiting myself to five (5) images/post so have to be somewhat brief. I am most interested in presenting concepts rather than keystrokes. " Proof is left to the student... "
I have not seen that problem before. Perhaps you have another sketch visible?
"It is a poor workman who blames his tools..."
Re: V0.19 Benchmarking--2019 Monthly Challenges #1,#2,#3,#4
I will have to work my way through FreeCAD to work out what's available to me.
That's precisely what I am talking about, but I am used to single sketch being used to create many bodies without additional carbon copy sketches, simply by selecting which elements of that sketch you want to use to create a specific body.
Of course I am mindful of avoiding comparisons, simply because they are pointless.
FreeCAD is what it is and "nostalgia" for something I could do with another CAD system is counterproductive
Well... if you look at the last picture of your exercise 1 (the one with a small inserted 3D view of finished design) you will see it is exactly the same as my picture, with master sketch still there in the middle of finished body
Re: V0.19 Benchmarking--2019 Monthly Challenges #1,#2,#3,#4
True enough, but it easily toggles off with the spacebar, at least with my version.
"It is a poor workman who blames his tools..."
Re: V0.19 Benchmarking--2019 Monthly Challenges #1,#2,#3,#4
and another mystery of FreeCAD solved
I wonder why toggle visibility menu command doesn't work (or only works when sketch is being edited)
but at least I have a way of doing it now - thank you!
Re: V0.19 Benchmarking--2019 Monthly Challenges #5
This rather simple object gives us the chance to present several additional concepts: variables, expressions, and external references. If you noticed in some of the previous examples there are dimensions 'trapped' in the pad and pocket features, i.e. in order to edit these you have to find and open the feature's property or task panels rather than editing the master sketch. This is because the pads and pockets are normal to the master sketch. Dimensional changes can be simplified by adding another master sketch(es) as is discussed in the images that follow:
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* Spreadsheet workbench: https://wiki.freecadweb.org/Sketcher_Workbench
** DynamicData add-on: https://github.com/mwganson/DynamicData
OS: Windows 10 (10.0)
Word size of OS: 64-bit
Word size of FreeCAD: 64-bit
Version: 0.19.22474 (Git)
Build type: Release
Branch: master
Hash: a44f8ffd427fa9b23b1f00dbf62d66cd152cd774
Python version: 3.8.5
Qt version: 5.12.6
Coin version: 4.0.0
OCC version: 7.4.0
Locale: English/United States (en_US)
.
* Spreadsheet workbench: https://wiki.freecadweb.org/Sketcher_Workbench
** DynamicData add-on: https://github.com/mwganson/DynamicData
OS: Windows 10 (10.0)
Word size of OS: 64-bit
Word size of FreeCAD: 64-bit
Version: 0.19.22474 (Git)
Build type: Release
Branch: master
Hash: a44f8ffd427fa9b23b1f00dbf62d66cd152cd774
Python version: 3.8.5
Qt version: 5.12.6
Coin version: 4.0.0
OCC version: 7.4.0
Locale: English/United States (en_US)
"It is a poor workman who blames his tools..."