Hence using a feature as Part feature for such purpose, as Part feature provides LCS?Zolko wrote: ↑Sun Dec 30, 2018 11:36 pmI such a case, you can define, very early in the process, LCS where parts and assemblies are functionally linked, assemble everything, and develop in parallel all sub-assemblies distributed between several engineers, and the master assembly will, automagically, always include all sub-assemblies at the correct placement.
I disagree. On the contrary, in real world situation, people expect a CAD system can do most of the calculation for them. Let's say we want to fix two plates with two holes. In theory, there are many ways to do this without needing an assembly. You can measure the angle of the holes in one of the plate. You can use sketch to map the holes of the first plate, and create the second plate with that sketch. The thing is, if you expect user to do this and do that, you don't really need an assembly system in the first place. Someone has created an entire engine using FC. But in real world, people expect to be able to do this,Zolko wrote: ↑Sun Dec 30, 2018 1:54 pmyes, "IF". But in the real world, in 90% of cases (probably closer to 99%) you don't need a complex solver, a part is positioned at a particular position. The assembly knows where the part is supposed to go (that's the target LCS), and the part knows where it is supposed to be attached (that's the attachment LCS).
That's how PartDesign body builds on, attaching sketch to existing body feature, and then create new feature. It works well because the body is supposed to produce fixed geometries, and you are actually building those geometries along the way, whereas in assembly, the parts are already built, possiblely from different people. AttachEgnine are in src/Mod/Part/App/Attacher.h/cpp.Zolko wrote: ↑Sun Dec 30, 2018 1:54 pmThat's an information I didn't know, thank-you. Could you please give more info on that ? Supposed, for example, that I have an assembly, a part, each having 2 LCS, and I want to attach — using your App::Link framework — the part by one of its LCS to the assembly, twice, once on each LCS. Would it be possible to do it today ?In fact, FreeCAD's AttachEngine is used for this purpose.
Hy Saso, I may understand what you mean. In fact I have to admit that, when building a large assembly, I always tend to make a tree like structure in the dependency graph, avoiding as much as possible the circular dependencies mentioned by realthunder.
This is where you make your mistake. No, at the beginning of a project, parts are not yet made, you only have a vague idea how all the — future — parts are going to fit together. This means that a project always begins with the master assembly, containing some datum objects, functional sketches, and allowed volumes. From there you derive sub-assemblies, fixed to the master assembly by datum objects, often LCS, and those sub-assemblies are distributed then to different people / groups.realthunder wrote: ↑Mon Dec 31, 2018 12:06 amwhereas in assembly, the parts are already built, possiblely from different people
Nice, thank-you, I'll try to understand what that does.AttachEgnine are in src/Mod/Part/App/Attacher.h/cpp.
Uh... No. Maybe that's the "proper" way of doing it for complex projects, but it most definitely not always begins that way. At work, we often create small assemblies for which we have already figured out the parts, therefore we don't need to start with a master assembly.Zolko wrote: ↑Mon Dec 31, 2018 11:18 amNo, at the beginning of a project, parts are not yet made, you only have a vague idea how all the — future — parts are going to fit together. This means that a project always begins with the master assembly, containing some datum objects, functional sketches, and allowed volumes.
Solidworks is not a high-end CAD system, it's mid-range.
FreeCAD
