Zolko wrote: ↑Sun Apr 18, 2021 12:13 pm
kcleung wrote: ↑Sat Apr 17, 2021 11:33 pm
So in assembly 4, how can one implement loose fit, transition fit and interference fit? It would be great if the workbench and the assembly data structure has a way to specify loose fit and interference fit, in particular the amount of interference.
This is an interesting question ... in today's implementation, all "fits" are nominal fits, without any specified tolerance. In all the projects that I have been doing, the tolerancing of fits is done at the end, for the final drawings and manufacturing process. We have never done such tolerancing in the assembly at the design process, it was always done at a second stage, after the prototyping and before the serial industrialization, because this depends on the manufacturing process.
For assembly to be of practical use, the system also needs to automatically validate all fits within the assembly, and to spot out any errors
This is clearly false.
Thank-you for your proposal, but I will close the issue.
For a CAD system to be complete, it is essential that apart from catering the prototyping stage, it should also cover the final stage up to the production - namely when we export each part to CNC, 3D printing and/or sheetmetal workbenches for production of G-code for manufacturing. So this is why I said it is essential to get the three types of fits sorted out in order to cater the serial industrialization stage.
The alternative of manually jigging each part for fit would be too labour-intensive and prone to failure.
The specification of fit will also allow validation of all assemblies before production.
Many CAD system including Solidworks, GrabCAD and AutoCAD have fits implemented.
This is what AutoCAD does:
https://knowledge.autodesk.com/support/ ... 6-htm.html
It allows the user to select one of the following fits:
Force and shrink fits (FN).
Clearance and location fits (LC).
Interference locational fits (LN).
Transition locational fits (LT).
Running and sliding fits (RC).
then the system will calculate deviations according to the Engineers Handbook.
we can use the AutoCAD approach as guidance when we implement it in the future
Please re-open the issue with a tag of enhancement or feature request to be implemented at some stage in the future.