Non modelled masses eg paints and coatings 1

[adrj]

When modelling parts which are subsequently coated eg galvenised there seems to be no method of adding the extra mass due to the coating other than changing the density to include an allowance. Ideally it should be linked to the surface area and worked out automatically. Has anybody a work around for this?

 

[MadMango]

Not sure if this is a workable solution, depends on the complexity of your parts. What I have done in the past to account for material build-up of a finish is to select a face or adjacent faces, and >Insert>Surfaces>Offset. Then I rename that feature in the FM. "The attempt and not the deed confounds us."

 

[macPT]

adrj,

The coated part is the result of adding a component (a machined part, a bended sheet,...) to another component(some amout of paint, some amout of Zinc) in witch you can consider as an assembly process (the painting job, the electroplating, the hot dip galvanizing). So what do you think of create an assembly with the metal part matted to a part (the coating) that can be a simple feature with the adjusted wheight?
This way, in your BOM, you do not forget all that is involved, including the material quantities, the coating costs and the assembly costs.

 

[MadMango]

To me that sounds like a bit of over kill, but I could see the use of that suggestion. Where I work we have routings that document how the part is manufactured, including added finishes.

The method I described above is strictly used during the design proces to account for material build-up if clearance is suspected to be a problem. We don't manufacture rocketships, so our tolerances are pretty lax (+/-.030 on a good day). "The attempt and not the deed confounds us."

 

[nozzlemaker]

One easy way you could do this, which would certainly be a bit of an overkill, is to use the shell feature. create a shell without selecting any faces but check the "shell outward" option. this will create a solid outside the volume occupied by your part. if any surfaces are not to be painted then you select them when doing the shell and no geometry will be created on them. then obviously you add the new weight of the shell to the original weight. if you want to be especially anal you could assemble the shell of "paint" onto the part in your assembly and so save yourself the bother of adding all the parts separately.

interestingly enough on the part that i tried, a 50 micron layer still added up to about 10 gramms while the full part is only about 200 gramms. I can appreciate that the weight of the paint may well be significant on small complex sheetmetal parts where your surface area is high relative to your volume.

 

[DetroitPickles]

ADRJ,

Are you getting the mass properties using the API? If so, in you code, can't you just multiply the weight by 3.5% (or whatever) for the galvanizing and "display" that answer instead?

Mr. Pickles