Part design / sketch qestion

[cncwhiz]

I have a part that I have sketched and padded. I want to draw a sketch on one of it's surfaces, and then do features with that sketch. Is this possible?

Coming from solidworks, so that's how I see what i am doing. Just trying to translate those functions to FreeCAD.

[drmacro]

It is possible, but not recommended because of the topological naming problem.

Simply create the sketch as normal and select the appropriate base plane.

Then go to the Property view and change the Attachment offset as needed.

[cncwhiz]

Thanks

Can you elaborate on the "going to the property view".

[drmacro]

PropView_annot.png (100.15 KiB) Viewed 475 times

[drmacro]

SketchAttach.gif (794.51 KiB) Viewed 470 times

[cncwhiz]

I see. Thanks.

I may struggle with this. I can get the sketch drawn by selecting a base plane, but an issue I am having is that I can't do dimensions to locate the sketch within / on my current part. For instance if I am trying to put a hole in the side of a part I have already padded, I need to be able to draw that sketch and locate it on the existing part. To do that I use the constraint that fixes the distance between two points, vertical or horizontal. I can locate the the features on my existing sketch geometry, but nothing on the previously drawn and padded part because it isn't technically active. The only available point to use is the X,Y, Z zero.

For example, in solidworks, I could grab the point at the intersection of two lines of the solid I was working on.

What can I do about this?

[drmacro]

With the sketch open, use the sketcher external geometry tool.

https://wiki.freecadweb.org/Sketcher_External

But, you should use external geometry from other sketches (not generated geometry, i.e. faces or edges that result from previous pads, pockets, etc.) to avoid the topo issue.

You can toggle the other sketch visible with the space bar and select geometry from it.

See Advice for creating stable models: https://wiki.freecadweb.org/Feature_editing

[cncwhiz]

OK. That fixed that. Able to get the external geometry tool and get that working, also using the property view to move the sketch to whatever surface i need.

Now I am trying to extrude or cut the hole that the geometry was drawn for. I tried using the pocket or hole buttons but I am not getting intended results. Is there anything else I need to know about using these?

[drmacro]

Yes, a subtle point. If I get what you asking...

Pocketing creates a negative, so, when you pocket you may need to check the reverse box. Otherwise it is pocketing into air.

[drmacro]

Oh, and the Hole tool gets only it's center from the selected sketch. The diameter, countersink, etc. is defined by the Hole tool dialog.


PS: read through the first pdf of the series linked in my sig below for more enlightenment on these topics.
(Yup, shameless plug... )