Animation Add-On

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sjam986
Posts: 23
Joined: Tue May 12, 2020 10:07 am

Re: Animation Add-On

Postby sjam986 » Thu May 28, 2020 9:48 pm

(*) bloody-hell, this asks for a "Record Sequence" button: any idea how this could be done ?
Yes, Please!
sjam986
Posts: 23
Joined: Tue May 12, 2020 10:07 am

Re: Animation Add-On

Postby sjam986 » Wed Jun 03, 2020 8:08 am

Stuck again. I have a model in Assembly4 of an engine base and crankshaft. The master sketch is ok and I have linked the crankshaft to the master sketch. When I animate the model the crankshaft rotates until it is in its originally drawn position, then swaps end to end and continues to rotate for another 180 degrees, swaps end to end again and finishes the rotation.
Any ideas?
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Zolko
Posts: 933
Joined: Mon Dec 17, 2018 10:02 am

Re: Animation Add-On

Postby Zolko » Wed Jun 03, 2020 10:26 am

sjam986 wrote:
Wed Jun 03, 2020 8:08 am
Any ideas?
classical FreeCAD topological naming problem.

The good way to do that is to create an LCS that will be rotating w.r.t. the fixed engine (attach the LCS to the fixed one, and in the AttachmentOffset set the angle to the variable that drives the angle). Then, attach the crankshaft to the rotating LCS. Also, attach a sketch to the rotating LCS, and draw there a single line. Then, in the sketch drawing the piston movement, import as an external reference the line from the rotating sketch, and do your drawing.

Asm4_V4.gif
Asm4_V4.gif (952.67 KiB) Viewed 133 times

https://forum.freecadweb.org/viewtopic. ... 06#p293179
try the Assembly4 workbench for FreCAD v0.19
install with Tools > Addon Manager > Assembly4 — tutorials here and here
sjam986
Posts: 23
Joined: Tue May 12, 2020 10:07 am

Re: Animation Add-On

Postby sjam986 » Fri Jun 05, 2020 10:49 am

Still in trouble.
I have created a very simple model of a crank - no parts or bodies yet - just a model with variables and a master sketch with one line from the origin to a point 23 mm radius on the YZ plane, 30 deg acw from the Y axis. The variables are Angle_crank = 30 and R_main = 23. I selected the master sketch and in Map Mode I selected LCS_Origin as the attachment with mode Object's YZ plane. In the master sketch the new Z axis is along the line from the origin.
I then selected the model, created a new coordinate system LCS_crank with first attachment 'Vertex' - 'Sketch_master:Vertex1' and second attachment 'Line' - 'Sketch_master:Edge1' with mode 'Align O-Z-Y'.
When animated the line rotates as it should in the YZ plane but the axes swap over as the new Y axis passes the old Z axis.
If I do the same process with the sketch on the XY plane, everything works fine. However, my engine has the X axis as the crank rotation axis and a vertical Z axis, so the sketch is in the YZ plane.
What am I doing wrong?
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Zolko
Posts: 933
Joined: Mon Dec 17, 2018 10:02 am

Re: Animation Add-On

Postby Zolko » Fri Jun 05, 2020 1:02 pm

sjam986 wrote:
Fri Jun 05, 2020 10:49 am
What am I doing wrong?
you should post this in the "Help" forum where it belongs
try the Assembly4 workbench for FreCAD v0.19
install with Tools > Addon Manager > Assembly4 — tutorials here and here
sjam986
Posts: 23
Joined: Tue May 12, 2020 10:07 am

Re: Animation Add-On

Postby sjam986 » Fri Jun 05, 2020 10:03 pm

OK. Will do.
cron