I am a mechanical engineer and have a good knowledge of PTC Creo (use at work) and a small knowledge of Solidworks. As I wanted to get a better overview of Freecad and assembly workbenches, I decided to model a small motor from this website : http://www.vapeuretmodelesavapeur.com/telechargements4/
I chose vertical beginner 1.
I learnt a lot on part design workbench, discovered sheet metal workbench. But my goal was to test every assembly workbench to try to catch the differences between each one and see which one suits best to me. I thought I would share my feelings on the forum so that it can help developers and/or other users. I do not mean to be hard to developers and I appreciate the effort it takes to get where Freecad is. It is just a little experiment for me to choose the workbench I am the more comfortable with. You will find below what I liked and what I liked less for each workbench. I do not intend to get a response on each point from developers but just give my impressions. They can be used or not, it is up to everyone. I could also elaborate if needed.
- There is a button to import part
- Automatic placement when constraint is given
- Similar to commercial CAD software : learning curve is fast
- Only possible constraints with current selection are active in toolbar
- Cannot access to part datum object for constraining
- Unable to know which constraints are conflicting
- Cannot rotate part when moving under constraint (I did not get it to work)
- Miss plane/cylinder tangent constraint
- Constraining with 2 coincident axis to lock rotation does not seem to work
- Possible to access all parts geometry and datum to constraint
- Need to move part before constraining
- Constraints not clear about what they do, it did not feel natural to me
- No import part button : drag and drop is not always easy with a big tree
- Need to prepare all interfaces object before constraining if you want to ensure reusability
- You have to open, save, reopen to start constraining
- All constraints are always available active no matter current selection
- Miss plane/cylinder tangent constraint
- No « reverse direction » option on relevant constraints
- Lot of clicks to do something
- Need to create assembly files before starting to work
- Solver sometimes tells you inconsistent constraint with what you think are consistent constraints
- Solver fails after moving a part even if it was OK before moving
- Good resilience to toponaming problems
- Once LCS are placed, constraining is easy
- You have to create a model, save, close, reopen before starting working
- You have to create each LCS. I would prefer automatic creation when constraining by geometry’s object
- You have to edit placement manually. A popup window at LCS creation would be nice
- LCS placement is sometimes not natural compared to what you would do in real life for assembly
- No « move under constraint » feature, only animation
- No access of subassemblies’ LCS (is it possible to work with subassemblies at all?)
- Cannot create 2 constraints on the same part : you have to use master sketch. Not my habitual workflow so not natural to me, but it works. To me, part offsetting from master sketch is more complicated than putting a plane coincident constraint.
I did not succeed in creating the assembly and having it moving under constraint with A2+ or assembly 3. I almost succeeded in getting it to work with assembly 4 and the animation of the master sketch but the assembly exploded during animation. Probably due to inconsistent signs in my master sketch. This could probably be solved with more time. In the end, I still don’ know which workbench I feel the more comfortable with! -_-
I know that the assembly I tried to model could be done easily by experts on any of the 3 assembly workbench. I did not spend a lot of time doing tutorials as from my experience, I thought it would be quite simple. A lot of « - » points could probably be solved with research and tutorials. But as I said at the beginning, this is just thoughts from a regular CAD user with its habits that tries something new. I think that with a unique workbench taking good points of every workbench and solving issues that would remain, Freecad would be more easy to get in for beginners or professional users of commercial CAD softwares that want to use open source softwares for personal use.
Thank you for the amazing work you do! I cannot (yet) contribute with code but I hope this can be my small part to help developing Freecad.