FC v0.17dev: Part Design Next Usecases and Best practices

[chrisb]

(I only know how to pick a edge from another sketch as a reference, not a point )

It is exactly the same process: Click the ExternalGeometry icon and then click an external point - instead of a line.

[schupin]

It is exactly the same process: Click the ExternalGeometry icon and then click an external point - instead of a line.

Oh
Thank you Chrisb, I've never noticed the yellow highlight on the points !
(and on my french version, the tooltip on the ExternalGeometry icon says that's for creating an edge)

[guillaumec]

Question from a relatively new user concerning the new part design:

I am working on a casing model with many small parts. Is it better to work in a single body part and add pads/pockets into it, or to make several sub bodies merged by boolean operations?

I started by using the first method in order to keep my tree view relatively clean, but one problem is that as my model grows more complex it becomes quite slow to edit because of the re computation. I am now tempted to restart the model only using boolean operations so that I can work on parts in isolation.

I attach a screenshot that shows the two approaches on a test model.

Screenshot from 2018-04-26 12-58-48.png (61.17 KiB) Viewed 1904 times

Any thought on that?

[HarryGeier]

Well,

i would have done that in a more simple way:

Create a base sketch,
Pad outer shape of bottom
Pad shape of walls
Pad shapes of separators

probably all based on a set of parameters from s worksheet or master sketch.

finally fillet the corners..

[chrisb]

I am working on a casing model with many small parts. Is it better to work in a single body part and add pads/pockets into it, or to make several sub bodies merged by boolean operations?

It depends. If you want to 3D print you should keep it all in one body, if you want to build it from single pieces (e.g. wood) you should model separate bodies. Use the master sketch technique anyway and import it into your several bodies with a ShapeBinder. There are no boolean operations required.

Your model shouldn't get slow with this rather simple model, perhaps Thickness is the show stopper. You avoid this by going the Harry way.

[schupin]

Well,

i would have done that in a more simple way:

Create a base sketch,
Pad outer shape of bottom
Pad shape of walls
Pad shapes of separators

probably all based on a set of parameters from s worksheet or master sketch.

finally fillet the corners..

Seemed a good exercice for me to pratice with sheets and master sketch !

I'm quite happy to succeed and have a ligth parametrised file !

Case.png (127.3 KiB) Viewed 1833 times

ParametricCase.FCStd

(52.31 KiB) Downloaded 116 times

[HarryGeier]

that´s good !

[miniellipse]

Seemed a good exercice for me to pratice with sheets and master sketch !

I'm quite happy to succeed and have a ligth parametrised file !

Hi schupin,

Would you be so kind as to tell me how did you manage copy lines from the master sketch into your sub-sketches? I took your file and and deleted the green lines in Sketch001 but I do not know how to link the geometry from your Master (sketch). The button, "Copies the geometry of another sketch (C,C)" does not seem to do anything. I'm using:

OS: Windows 7
Word size of OS: 64-bit
Word size of FreeCAD: 64-bit
Version: 0.17.13515 (Git)
Build type: Release
Branch: releases/FreeCAD-0-17
Hash: e17b340949b75a226cc7d89989b0aa238ccfc75f
Python version: 2.7.14
Qt version: 4.8.7
Coin version: 4.0.0a
OCC version: 7.2.0
Locale: English/UnitedStates (en_US)


thank you for your help.

[chrisb]

Would you be so kind as to tell me how did you manage copy lines from the master sketch into your sub-sketches?

They are referenced by using "External Geometry". In the "Elements" section of the sketcher's panel to the left there are the elements subsequently numbered beginning from 1. In Sketch001 they are numbered from 1 to 12. These are the non-external elements. Then comes a gap in numbering and then it continues. In Sketch001 it is from 15 to 24, all of them being points here. These are the exernal references. They can be used together with constraints to define the sketch.

If you copy sketches instead of using external references you are breaking the parametricity of your model.

[schupin]

Hi,

I used "create an edge linked to an external geometry" to link my sketches to the master.
But, like chrisb said before, I just add points from the master geometry (not the complete edge)

But I feel stupid, I can't see how you made the link between your master sketch and the others ?
Your sketch001 possesses 2 points with a "red cross" that seemed to be picked from the master sketch. I don't know how you did it ?
(I only know how to pick a edge from another sketch as a reference, not a point )

It is exactly the same process: Click the ExternalGeometry icon and then click an external point - instead of a line.

EDIT : chrisb , you were faster than me