Why is Pocket not working for me?

[DAP]

Standard Boiler Plate:
OS: Linux Mint 18.3 Sylvia
Word size of OS: 64-bit
Word size of FreeCAD: 64-bit
Version: 0.17.13515 (Git)
Build type: None
Branch: releases/FreeCAD-0-17
Hash: e17b340949b75a226cc7d89989b0aa238ccfc75f
Python version: 2.7.12
Qt version: 4.8.7
Coin version: 4.0.0a
OCC version: 7.2.0
Locale: English/UnitedStates (en_US)

I am attempting to trim the edge of a pad with a pocket, but all that happens is the trim line shows up on the surface of the object.

PocketFailure.png (8.68 KiB) Viewed 1267 times

I have checked and removed any undetected redundant constraints from the sketch, but it still does not pocket properly.

[chrisb]

Your first Sketch is not properly constraint. Is there a good reason why you modeled it skewed? Modeling would be easier if it was upright, and you can of course turn it later.

[chrisb]

I have repaired and simplified the model:
- deleted fancy construction geometry
- moved to the center instead of having it somewhere free in space
- turned it upright while skewing the whole body
- replaced perpendiculars with horizontal and vertical constraints

[DAP]

There is a very good reason I'm building it skewed. That is the final position I want that part of the design to be in.
I already built it upright once expecting to be able to shift it and rotate this part and continue building the rest of the object, but so far I have found this impossible. There is no method in freecad to translate, or rotate part of the construction of a body, then continue to add features to the body in its new orientation. I even went so far as to try changing the body location and orientation and using the boolean operations to create a new body with this orientation, but the boolean operations ignore the location and orientation of the tool body, and only use the original orientation of the body. I spent the last week attempting to move forward with that approach without success.

So this was an attempt to build all of the parts in their final orientation.

Please let me know what constraints are improper in the 1st sketch. I know that the sketchers idea of fully constrained allows some types of redundant constraints, but so far I have only seen that with horizontal and vertical constraints.

[chrisb]

Please let me know what constraints are improper in the 1st sketch.

If you remove the vertical construction line the "undefined degrees of freedom" message vanishes.

[NormandC]

There is a very good reason I'm building it skewed. That is the final position I want that part of the design to be in.

And it makes sense to build it skewed, I've seen your other topic where you showed your attempt at building legs underneath.

But there is a middle ground: rather than make the geometry skewed inside the sketch, you could skew the sketch itself; then create geometry in a straight manner inside it.

I have to go, but I'll try to come back later and show you an example.

[chrisb]

There is no method in freecad to translate, or rotate part of the construction of a body, then continue to add features to the body in its new orientation.

You can use the skewed body as in my last upload and continue with another body using a ShapeBinder. It respects the Placemement of the body.

Edit: Normand will show you the variant using the Sketch's AttachmentOffset.

[DAP]

I have made some progress. I redid my 1st sketch, which of course broke everything I had done after that, but I kind of expect to have to start over many times with FreeCAD.
Anyway, I am at the point where I wish to add some fillets. Unfortunately, selecting an edge (see selected edge) and clicking on the fillet instantly crashes FreeCAD.

FilletCrash.png (16.43 KiB) Viewed 1214 times

Any suggestion on how to avoid this crash?

[chrisb]

If such a problem occurs, you should check the object with Part->CheckGeometry with BOPCheck enabled https://www.freecadweb.org/wiki/index.p ... ckGeometry. In this case it shows several errors.

[chrisb]

Sketch003 has some constraints missing. Although this should be avoided, the problem is, that the inner slot is not connected to the previous state, Pocket. So there are probably some residues prohibiting subsequent features.