Proposition of new workbench: Kinematic Scheme

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eggy
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Joined: Thu Jul 30, 2015 12:56 pm

Re: Proposition of new workbench: Kinematic Scheme

Postby eggy » Sun Apr 08, 2018 9:07 pm

That is sad. My condolences to his friends here and his family. Thank you for letting me know.
mfasano
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Re: Proposition of new workbench: Kinematic Scheme

Postby mfasano » Wed Apr 11, 2018 12:41 pm

there is a program that does what you are asking; Oddly enough, it is called freecad. This company sells his kinematic routines to other cad software; I think Alibre is one.
mfasano
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Re: Proposition of new workbench: Kinematic Scheme

Postby mfasano » Wed Apr 11, 2018 6:18 pm

I forgot to give the address for freecad kinematic software

http://www.ar-cad.com/freecad/index.html
Jee-Bee
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Re: Proposition of new workbench: Kinematic Scheme

Postby Jee-Bee » Wed Apr 11, 2018 9:07 pm

mfasano
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Re: Proposition of new workbench: Kinematic Scheme

Postby mfasano » Thu Apr 12, 2018 11:59 am

Here is a list of open source kinematic routines.

Open Dynamics Engine http://www.ode.org
PROJECTCHRONO https://projectchrono.org
FreeDyn http://www.freedyn.at
Hotint http://www.hotint.org
Bullet Physics Library http://bulletphysics.org/wordpress/
PositionBasedDynamics http://www.interactive-graphics.de
Moby http://physsim.sourceforge.net/index.html
Rigid Body Dynamics Library https://rbdl.bitbucket.io
Siconos: nonsmooth numerical simulation http://siconos.gforge.inria.fr/4.1.0/html/index.html
Solfec https://code.google.com/archive/p/solfec/
MBDyn https://www.mbdyn.org/?Homepage
simbody https://simtk.org/projects/simbody/


I am not sure if this is open source.
Robotran http://www.robotran.be
Cid0rz
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Joined: Sat Jun 17, 2017 10:18 am

Re: Proposition of new workbench: Kinematic Scheme

Postby Cid0rz » Mon Jun 18, 2018 12:59 am

Hello everybody,

Sorry to read here about Roland, my condolences.

Regarding simulating linkage mechanisms I'm searching for some nice tool. I've tried some mentioned here but I've not found a nice, complete hackable one. I'm not a programmer so my idea was to try to modify the sketcher and to do a macro/simple workbench to be able to study some mechanisms, particularly steam train regulation mechanisms :D. It would be nice to have a reference element and plot the kinematic curves. An interesting idea even if is only one developer and still full of bugs is https://github.com/KmolYuan/Pyslvs-PyQt5. Are there plans to proceed with this topic? Is there a better tool in FreeCAD to start from to do what I intend than the sketcher? I think 3D would be very complex since a single part of a mechanism can be achieved in many ways, so to study the kinematics a 2D tool should be good enough.

Thank you for the tools and community
fdomateu
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Joined: Thu May 17, 2018 7:14 am

Re: Proposition of new workbench: Kinematic Scheme

Postby fdomateu » Mon Jun 18, 2018 8:13 pm

Hello everybody,

I have been reading this discusion and I think that is an interesting issue. I would like to get people involve on the creation of a library WB to avoid that every WB has his oun parts (Bolts, Fasteners, Arch, flamingo, ose piping WB, etc.). you can find this open discussion at the following link:

https://forum.freecadweb.org/viewtopic.php?f=8&t=28798

For this WB that I would like to create, I think that this is an important aspect to take in consideration, is the only way to make a WB that will work over the different new release versions without big changes.

For other side, I do not understand the way how has been deviated this discussion. I consider that has start in a good way but if I check the documentation from FreeCAD, I think tat there is a pre-work make for part of the developers and nobody at this discussion has mentioned that. Reading the assembly project wiki, link bellow, averyone can see that the Physics simulation interface has been planed. Open Dinamics Engine is one of the proposes made. An other example is the external workench Assembly3, it is in development and they have used python as SolveSpace.

https://www.freecadweb.org/wiki/Assembly_project

Finally, according to my understanding on the work made at the released version 0.17, the big work made by the developers has been the Part/PartDesign definition to be able to go forwards with the Assembly WB. Is my understanding not true?
triplus
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Re: Proposition of new workbench: Kinematic Scheme

Postby triplus » Mon Jun 18, 2018 8:38 pm

As for assembly capabilities (with relations) Assembly 2, Assembly 2 plus, Assembly 3 workbenches are available ATM. On how much each of them is suitable for kinematic purposes i don't know. Likely that depends on the use case. As for PartDesign NEXT. In theory the changes introduced were planed to be somehow Assembly related. But likely a big part of PartDesign NEXT effort is/was PartDesign oriented. And therefore there is no direct relation to Assembly/Kinematic. Maybe local coordinate system feature will play a role once some Assembly/Kinematic solution emerges that utilizes it!

As for different workbenches in existence. Likely your effort to try to bring it under the same workbench will end up in the scenario where different workbenches in existence +1 will be the outcome. ;) But if you will do a good job and there will be an user base. For sure it will be used. As luckily when it comes to FreeCAD "competing workbenches" usually result in more user choice and higher level of possibility that a command that does something you are after exists. It's not about using one or another but instead using whatever is useful to you. The commands can be located in different workbenches. In addition specialized workbenches like fasteners, pipes, beams ... can result in less user facing complexity (confronted with less features) and individual developer related maintenance work needed over time.
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microelly2
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Re: Proposition of new workbench: Kinematic Scheme

Postby microelly2 » Tue Jun 19, 2018 7:18 am

Simulation can become very complex, so I think a better way than a workbench from scratch is to create an interface for example to open modellica.
https://openmodelica.org/
A major task is to map FreeCAD models to modelica models and get the simulation results back.
Dorantor
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Re: Proposition of new workbench: Kinematic Scheme

Postby Dorantor » Wed Aug 15, 2018 3:03 pm

microelly2 wrote:
Tue Jun 19, 2018 7:18 am
Simulation can become very complex, so I think a better way than a workbench from scratch is to create an interface for example to open modellica.
https://openmodelica.org/
A major task is to map FreeCAD models to modelica models and get the simulation results back.
I strongly agree with this idea. I've tried multiple multibody simulation software and so far, open modellica has been very helpful to me. There is also an option to import some type of CAD files in open modellica although this didn't work for me.

I have zero knowledge in programming so I don't know what's better or possible but my idea would be to translate the mechanical data and constraints from a Freecad assembly into open modellica blocks consisting of joint blocks and CAD body blocks. Then I can add a PID controller blocks for example to these generated blocks by Freecad.

A commercial variant of this idea would be the plug-in in Solidworks for Simscape Multibody from Matlab. Like the idea stated above, it imports CAD data from Solidworks into Simscape as body blocks (for geometry, inertia, weight etc.) and joint blocks (degrees of freedom, limitations of movement).

Open modellica has its own build-in 3D visualization and it can plot graphs so I don't see the necessity to translate those results back into Freecad, making it easier to build such a 'plug-in'.