Help with assembly 4 - coming from solidworks

[cncwhiz]

Guys, I'm really trying my best to learn this. Please forgive my ignorance, I come from solidworks and have that imbedded in memory. I am trying to understand the differences and make a simple assembly. My needs of a 3D assembly file are not very complicated, and I am trying to do a basic assembly to get the hang of things before I start going more complicated. Coordinate systems or planes don't even matter to me. All I need is to be able to draw parts in 3D with specific dimensions, and put them together in an assembly to check fits and clearances. That's all..

ignore the basic shapes of the parts. I don't need to draw the axis and import the bearing in the tutorial to figure out what I am trying to figure out. I just drew two shapes and padded them to make two "parts."

I have this file I am working on. I loosely followed the tutorial found on youtube and I have basically gotten it to the point where everything is in the work space and I am trying to manipulate the parts to put them together. In solidworks, the assembly files use "mates." So if I want to put one part up against another part, I use a mate to do that. There are different types of mates, but they all work on that principle.

Is the way that I am used to doable in freecad? The way the parts in the assembly now they seem locked together. I can't even seem to move them freely in space.

[bryancole]

Since I have just been using assembly4 to good success I figure I'll reply to this. FreeCAD assembly4 doesn't work like SolidWorks Mates. In fact, IIRC, SolidWorks Mates are closer to the constraints-system of the A2+ workbench.

Although the assem4 docs recommend putting each of your parts in a separate file, I have found things work fine modelling everything in a single project (ok for small projects). Start by creating an Assembly Model object. This provides a "Model" container for your assembly, and a "Parts" subfolder where you can create individual parts. The key thing to understand is that in order to build up an assembly, every part needs to include one or more LCS (local coordinate systems). These are simply used as attachment points for building the assembly. The basic workflow I use is:
- create separate parts in the "Parts" folder. Draw using the Part Design workbench like normal.
- add LCS at all the important assembly-points on each part. E.g. at screw-holes, mating surfaces etc. Give each LCS a meaningful name. <---
- add parts to your assembly using the "insert link to a part" button. Once you've selected the part to insert, you need to select 1) the existing LCS in the assembly where the part is to be attached (lets call this the parent LCS) and 2) the LCS in the new linked part to attach to the parent. Typically, you need to rotate the coordinate systems to get the orientation you want. There are easy buttons to do 90-degree rotations. Other rotations and offsets are possible by editing the attachment properties.
- The initially empty parent assembly contains a origin LCS which acts as the anchor point to attach the first part.
- If you need to create new geometries which reference assembled parts, you can use datums (and maybe the subshapebinder). Referencing across parts in an assembly is a tricky area which I'm still figuring out.
- Remember anything in the tree can be hidden/shown using spacebar.

Well, hope this helps. I'm a newbie too so feel free to correct me if I'm talking rubbish. Assembly4 is really awesome once you get the hang of it.

[cncwhiz]

The A2+ workbench was exactly what I was looking for. Now if I can just get the constraints understood I will be good to go. The constraints act somewhat like mates, but I'm still trying to figure out how to get them aligned properly to what I am telling them to do.

[jjubenv]

I recently assembled (A2+ workbench) a 5 piece kitchen cabinet door using Joko Engineering's video as a guide to get started.

https://www.youtube.com/watch?v=atO2sR5hp5w

This was all I needed to get going. There were some quirks (FreeCAD closed on me a few times), but in the end I got it assembled without much fuss.

OS: Debian GNU/Linux 10 (buster) (GNOME/gnome)
Word size of OS: 64-bit
Word size of FreeCAD: 64-bit
Version: 0.19.22960 (Git) AppImage
Build type: Release
Branch: master
Hash: c5a4b01d2e4218bcc0eb6650337650a6c65ef0e4
Python version: 3.8.6
Qt version: 5.12.5
Coin version: 4.0.0
OCC version: 7.4.0
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