V0.19 Top Down Assembly Design Using Assembly4--Update #11
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Re: V0.19 Top Down Assembly Design Using Assembly4--Update #3 Antique Blowtorch
A few of you are still hanging in there (435 views last count of the arbor press details) so I will continue with some of the details of the work process for the third project, the antique blowtorch:
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For you diehards who may still be following this post, I will try to find some interesting details of the work process for the next project, the geared handgrinder. Hopefully, by detailing all of the projects you will be as convinced as I am of the importance of master sketches and Assembly4 for top down design.
So, check back in a week or so.
OS: Windows 10 (10.0)
Word size of OS: 64-bit
Word size of FreeCAD: 64-bit
Version: 0.19.21937 (Git)
Build type: Release
Branch: master
Hash: 0de5a290113800dc5779a76d7e216bd882e0ed1e
Python version: 3.6.8
Qt version: 5.12.1
Coin version: 4.0.0a
OCC version: 7.3.0
Locale: English/United States (en_US)
.
For you diehards who may still be following this post, I will try to find some interesting details of the work process for the next project, the geared handgrinder. Hopefully, by detailing all of the projects you will be as convinced as I am of the importance of master sketches and Assembly4 for top down design.
So, check back in a week or so.
OS: Windows 10 (10.0)
Word size of OS: 64-bit
Word size of FreeCAD: 64-bit
Version: 0.19.21937 (Git)
Build type: Release
Branch: master
Hash: 0de5a290113800dc5779a76d7e216bd882e0ed1e
Python version: 3.6.8
Qt version: 5.12.1
Coin version: 4.0.0a
OCC version: 7.3.0
Locale: English/United States (en_US)
"It is a poor workman who blames his tools..."
Re: V0.19 Top Down Assembly Design Using Assembly4--Update #4--Geared Hand Grinder
This is the 4th example chosen to demonstrate the advantages of the master sketch approach and the Assembly4 workbench for top down design. This is a geared hand grinder design loosely based on one found in a restoration video on YouTube.
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Note that in all of the examples thus far the bodies were all created in-context in the same file placed in a parts folder. Assembly4 links are used to assemble these bodies and to add fasteners or duplicate bodies. This may seem redundant, but it does add the ability to independently change body locations in the Model assembly by changing the attachment offsets without affecting the master sketch while still keeping the interface relationships intact. For example, if you wanted to move the main housing assembly elevation with respect to its adjustable base, you simply change the placement property of the main housing and all of its attached bodies follow. This ability becomes more obvious when you want to articulate or animate the model to verify proper motion and internal clearances without changing the master sketches.
Next update (#5) is the steampunk cigarette lighter model which shows how to use link arrays to simplify assembly with Assembly4.
OS: Windows 10 (10.0)
Word size of OS: 64-bit
Word size of FreeCAD: 64-bit
Version: 0.19.22111 (Git)
Build type: Release
Branch: master
Hash: cb2099aa6bb287a8d7843eb70684cce79bdef26b
Python version: 3.6.8
Qt version: 5.12.1
Coin version: 4.0.0a
OCC version: 7.3.0
Locale: English/United States (en_US)
.
Note that in all of the examples thus far the bodies were all created in-context in the same file placed in a parts folder. Assembly4 links are used to assemble these bodies and to add fasteners or duplicate bodies. This may seem redundant, but it does add the ability to independently change body locations in the Model assembly by changing the attachment offsets without affecting the master sketch while still keeping the interface relationships intact. For example, if you wanted to move the main housing assembly elevation with respect to its adjustable base, you simply change the placement property of the main housing and all of its attached bodies follow. This ability becomes more obvious when you want to articulate or animate the model to verify proper motion and internal clearances without changing the master sketches.
Next update (#5) is the steampunk cigarette lighter model which shows how to use link arrays to simplify assembly with Assembly4.
OS: Windows 10 (10.0)
Word size of OS: 64-bit
Word size of FreeCAD: 64-bit
Version: 0.19.22111 (Git)
Build type: Release
Branch: master
Hash: cb2099aa6bb287a8d7843eb70684cce79bdef26b
Python version: 3.6.8
Qt version: 5.12.1
Coin version: 4.0.0a
OCC version: 7.3.0
Locale: English/United States (en_US)
Last edited by ppemawm on Thu Aug 06, 2020 4:14 pm, edited 1 time in total.
"It is a poor workman who blames his tools..."
Re: V0.19 Top Down Assembly Design Using Assembly4--Update #5 Steampunk Lighter
This is the 5th example from the original post that demonstrates use of PartDesign master sketches and Assembly4 during top-down design of a steampunk cigarette lighter found in a restoration video on YouTube. Comments about the work process are included in the captions of the following screen shots:
I have another small project to report in a week or so that uses a similar design approach. I chose this new project to specifically learn more about the worm gear object in the FCGear workbench. It is a simple Bilstein spiral jack from the 1930's found here: https://www.youtube.com/watch?v=6iDJNGdMFls
If you are not bored yet, please stay tuned.
OS: Windows 10 (10.0)
Word size of OS: 64-bit
Word size of FreeCAD: 64-bit
Version: 0.19.22111 (Git)
Build type: Release
Branch: master
Hash: cb2099aa6bb287a8d7843eb70684cce79bdef26b
Python version: 3.6.8
Qt version: 5.12.1
Coin version: 4.0.0a
OCC version: 7.3.0
Locale: English/United States (en_US)
I have another small project to report in a week or so that uses a similar design approach. I chose this new project to specifically learn more about the worm gear object in the FCGear workbench. It is a simple Bilstein spiral jack from the 1930's found here: https://www.youtube.com/watch?v=6iDJNGdMFls
If you are not bored yet, please stay tuned.
OS: Windows 10 (10.0)
Word size of OS: 64-bit
Word size of FreeCAD: 64-bit
Version: 0.19.22111 (Git)
Build type: Release
Branch: master
Hash: cb2099aa6bb287a8d7843eb70684cce79bdef26b
Python version: 3.6.8
Qt version: 5.12.1
Coin version: 4.0.0a
OCC version: 7.3.0
Locale: English/United States (en_US)
"It is a poor workman who blames his tools..."
Re: V0.19 Top Down Assembly Design Using Assembly4--Update #6 Spiral Jack
This is the 6th example of a top down design of an assembly using PartDesign, master sketches, and Assembly4 workbench based on a restoration video of an antique Bilstein spiral jack found at https://www.youtube.com/watch?v=6iDJNGdMFls
Images from the model and a few brief comments about the work process are as follows:
.
Questions or comments are welcome. The model is available for review or criticism via a Dropbox link if you contact me directly with a PM.
In the meantime, with all this spare time I have with Covid19 isolation here in NYC, I have been working on another assembly of a two-speed geared hand drill found at: https://www.youtube.com/watch?v=VoiEuyAFLHM This is a good project to challenge yourself with the bevel gear objects from the FCGear workbench incorporated in a complex PartDesign body.
OS: Windows 10 (10.0)
Word size of OS: 64-bit
Word size of FreeCAD: 64-bit.
Version: 0.19.22261 (Git)
Build type: Release
Branch: master
Hash: 1c432fd6170b7904592a224194e42d3c566707a6
Python version: 3.6.8
Qt version: 5.12.1
Coin version: 4.0.0a
OCC version: 7.3.0
Locale: English/United States (en_US)
Images from the model and a few brief comments about the work process are as follows:
.
Questions or comments are welcome. The model is available for review or criticism via a Dropbox link if you contact me directly with a PM.
In the meantime, with all this spare time I have with Covid19 isolation here in NYC, I have been working on another assembly of a two-speed geared hand drill found at: https://www.youtube.com/watch?v=VoiEuyAFLHM This is a good project to challenge yourself with the bevel gear objects from the FCGear workbench incorporated in a complex PartDesign body.
OS: Windows 10 (10.0)
Word size of OS: 64-bit
Word size of FreeCAD: 64-bit.
Version: 0.19.22261 (Git)
Build type: Release
Branch: master
Hash: 1c432fd6170b7904592a224194e42d3c566707a6
Python version: 3.6.8
Qt version: 5.12.1
Coin version: 4.0.0a
OCC version: 7.3.0
Locale: English/United States (en_US)
"It is a poor workman who blames his tools..."
Re: V0.19 Top Down Assembly Design Using Assembly4--Update #6
Exquisite!.
Ever consider live streaming your CAD modeling sessions? I'm sure you'd pick up a following pretty fast (as you already have one )
Ever consider live streaming your CAD modeling sessions? I'm sure you'd pick up a following pretty fast (as you already have one )
Alone you go faster. Together we go farther
Please mark thread [Solved]
Want to contribute back to FC? Checkout:
'good first issues' | Open TODOs and FIXMEs | How to Help FreeCAD | How to report Bugs
Please mark thread [Solved]
Want to contribute back to FC? Checkout:
'good first issues' | Open TODOs and FIXMEs | How to Help FreeCAD | How to report Bugs
Re: V0.19 Top Down Assembly Design Using Assembly4--Update #6
Thanks for your kind comment.
I have, for about 10 seconds. A high quality video must take an inordinate amount of time which I am not willing to invest at this time.
I would rather model and share snapshots to encourage or convince new users that FreeCAD has got what it takes for real mechanical parametric design work.
"It is a poor workman who blames his tools..."
Re: V0.19 Top Down Assembly Design Using Assembly4--Update #7 Two-Speed Hand Drill
This is the last of the projects in this series demonstrating top down design of assemblies using master sketches and Assembly4. This is a model of a two-speed hand drill reverse engineered from a restoration on YouTube: https://www.youtube.com/watch?v=VoiEuyAFLHM
A few comments about the modelling process which is similar to the previous projects follow in the captions of the images below:
.
A few concluding remarks regarding top down design and in-context modelling:
1. An assembly master sketch(es) is essential to capture design intent and to control interface locations during the design process.
2. My mantra is "keep the master simple but not too simple". Only experience will tell you how simple.
3. Sketcher carbon copies ensure linkage to the master sketch and dramatically improve sketch productivity.
4. Assembly4 facilitates the top down design process with a simple approach using local coordinate systems as "connectors" to insure 6-degree solver function.
5. Nearly any assembly constraint solver for mechanical motion can be created using Assembly4 expressions and variables. I am not a fan of too much automation that buries this function in the assembly software selectable only by myriad of tool buttons.
6. Robust modelling strategies are necessary especially for top-down design since the model will go through many changes during the design process. Avoid model breakage by attaching sketches and individual body local coordinate systems only to master sketches or origin planes.
7. I no longer use the master sketch for controlling any mechanical motion due to weaknesses in the sketcher solver for any changes over a wide range. It is more reliable to apply motion constraint solvers via expressions for the LCS's or body link attachment offset properties.
The model files from any of the projects are available to anyone for review or critique by PM request. The bevel gear template is also available by request. The files are too large to attach.
If you want to learn top down design find a restoration video of a mechanical device that interests you and give it a go. All the information you need can be gleaned from the video with a bit of effort. Using this approach rather than working from drawings is better IMO because it will force you to develop robust models that can withstand many changes as the design evolves.
OS: Windows 10 (10.0)
Word size of OS: 64-bit
Word size of FreeCAD: 64-bit
Version: 0.19.22261 (Git)
Build type: Release
Branch: master
Hash: 1c432fd6170b7904592a224194e42d3c566707a6
Python version: 3.6.8
Qt version: 5.12.1
Coin version: 4.0.0a
OCC version: 7.3.0
Locale: English/United States (en_US)
A few comments about the modelling process which is similar to the previous projects follow in the captions of the images below:
.
A few concluding remarks regarding top down design and in-context modelling:
1. An assembly master sketch(es) is essential to capture design intent and to control interface locations during the design process.
2. My mantra is "keep the master simple but not too simple". Only experience will tell you how simple.
3. Sketcher carbon copies ensure linkage to the master sketch and dramatically improve sketch productivity.
4. Assembly4 facilitates the top down design process with a simple approach using local coordinate systems as "connectors" to insure 6-degree solver function.
5. Nearly any assembly constraint solver for mechanical motion can be created using Assembly4 expressions and variables. I am not a fan of too much automation that buries this function in the assembly software selectable only by myriad of tool buttons.
6. Robust modelling strategies are necessary especially for top-down design since the model will go through many changes during the design process. Avoid model breakage by attaching sketches and individual body local coordinate systems only to master sketches or origin planes.
7. I no longer use the master sketch for controlling any mechanical motion due to weaknesses in the sketcher solver for any changes over a wide range. It is more reliable to apply motion constraint solvers via expressions for the LCS's or body link attachment offset properties.
The model files from any of the projects are available to anyone for review or critique by PM request. The bevel gear template is also available by request. The files are too large to attach.
If you want to learn top down design find a restoration video of a mechanical device that interests you and give it a go. All the information you need can be gleaned from the video with a bit of effort. Using this approach rather than working from drawings is better IMO because it will force you to develop robust models that can withstand many changes as the design evolves.
OS: Windows 10 (10.0)
Word size of OS: 64-bit
Word size of FreeCAD: 64-bit
Version: 0.19.22261 (Git)
Build type: Release
Branch: master
Hash: 1c432fd6170b7904592a224194e42d3c566707a6
Python version: 3.6.8
Qt version: 5.12.1
Coin version: 4.0.0a
OCC version: 7.3.0
Locale: English/United States (en_US)
"It is a poor workman who blames his tools..."
Re: V0.19 Top Down Assembly Design Using Assembly4--Update #7
The designs you are capable of in FC are NextF***ingLevel, sir.
I would buy a book that you'd write and publish.
I seriously think you should do something like that.
Alone you go faster. Together we go farther
Please mark thread [Solved]
Want to contribute back to FC? Checkout:
'good first issues' | Open TODOs and FIXMEs | How to Help FreeCAD | How to report Bugs
Please mark thread [Solved]
Want to contribute back to FC? Checkout:
'good first issues' | Open TODOs and FIXMEs | How to Help FreeCAD | How to report Bugs
Re: V0.19 Top Down Assembly Design Using Assembly4--Update #7
the signature perfectly fits to ppemawm it is as good as jürgens one.
Re: V0.19 Top Down Assembly Design Using Assembly4--Update #8 Rachet Screwdriver
I would be remiss not to present an alternative work process, perhaps more common, using Assembly4. This is a model of an antique rachet screwdriver inspired by another restoration YT video: https://www.youtube.com/watch?v=JmSXo0XdWoA. However, in this project each of the bodies for the assembly are saved in individual files and assembled with Assembly4. One disadvantage with creating all of the bodies in a single file during top-down design is that the bodies cannot be reused in other projects without saving them to a separate file using copy/paste which must include all of their dependencies (linked mastersketches, etc.).
In the following approach, each body has its own file, but each is created in-context in the assembly file during the assembly design process. No assembly master sketch is used. The following screenshots include a few comments on this process.
.
I just cannot say enough about how flexible and relatively simple it is to use Assembly4 for top-down or bottom-up design. I do alot of assembly design work and find that Assembly4 has always met or exceeded my expectations. The screwdriver files are available for review and critique by request via PM. Questions or comments are welcome as always.
OS: Windows 10 (10.0)
Word size of OS: 64-bit
Word size of FreeCAD: 64-bit
Version: 0.19.22261 (Git)
Build type: Release
Branch: master
Hash: 1c432fd6170b7904592a224194e42d3c566707a6
Python version: 3.6.8
Qt version: 5.12.1
Coin version: 4.0.0a
OCC version: 7.3.0
Locale: English/United States (en_US)
In the following approach, each body has its own file, but each is created in-context in the assembly file during the assembly design process. No assembly master sketch is used. The following screenshots include a few comments on this process.
.
I just cannot say enough about how flexible and relatively simple it is to use Assembly4 for top-down or bottom-up design. I do alot of assembly design work and find that Assembly4 has always met or exceeded my expectations. The screwdriver files are available for review and critique by request via PM. Questions or comments are welcome as always.
OS: Windows 10 (10.0)
Word size of OS: 64-bit
Word size of FreeCAD: 64-bit
Version: 0.19.22261 (Git)
Build type: Release
Branch: master
Hash: 1c432fd6170b7904592a224194e42d3c566707a6
Python version: 3.6.8
Qt version: 5.12.1
Coin version: 4.0.0a
OCC version: 7.3.0
Locale: English/United States (en_US)
"It is a poor workman who blames his tools..."