Part Design Parts

This page is part of a planned series on FreeCad now being revised for .18 . Click on the category FreeCad for some more information. I work on it as I do FreeCadprojects so this can be very on and off. As of 2019 Dec it is on. This is not a document that is really ready for general reading.

• Most of my models are designed to be parametric with many of the parameters having master control in a spreadsheet. So the notes here are more or less based on that assumption.

Introduction

Part design is arguably the most useful workbench for 3 D printing. It should not be confused with the Part workbench. What is the difference? One brief summary would be that Part Workbench starts with basic 3D geometric objects and modifies and combines them. The Part Design workbench on the other hand seems to be more sketch based. Sketches can project positive ( pad ) or negative ( pocket ) space. Parts and operations can be combined between the two workbenches but sometimes do not play nice particularly with parametric designs.

• All workbenches at a glance · A FreeCAD manual

Issues with sketches

The biggest problem seems to be a sketch loosing track of the face it is attached to. So the advice, as I decode it, is to only attach sketches to either a body axis plane or a datum plane.

Part Design

If you used the old part design workbench ( .16 and earlier ) you may have some re-adjustment to the now one. I more or less considered Part Design and Part workbenches to be pretty much sections of a larger workbench. In particular parts from the Part workbench were freely and commonly used in the Part Design workbench. This no longer seems to be the case. Now Part Design parts should be used inside a body and it seems that Part workbench parts cannot be moved into a body. ( example file would be nice ) In some ways a cylinder is not a cylinder. If you need a cylinder for the Part Design look under Part Design -> Part Design -> Create Additive Primitive -> Additive Cylinder

Russ it seems that Part Parts can be used in a part design body in two ways: Drag and drop them in this creates a xxx which then can be used ?? A sketch attached to a Part not in the body produces a pad that is in the body

Body

Typically in part design you are making a body. At a later stage bodies may be combined ( subtracted ?? )

• A sketch may be copied between bodies, not entriely clear what it binds to
• a pad may not be copied into a body but some represention of it ( a base ferture does )

Datums

So what is a datum ( actually here a datum plane ). It is a plane that you attach things to. But what do you attach a datum to? Attach it to a plane in a body. You can then move an rotate the datum to any place you want it.

Note on datum coords ??

ShapeBinder

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