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How to model paint in an assembly? 1

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Brad82

Mechanical
Jun 11, 2004
19
I have an assembly made from 4 components in Wildfire 2.0. This assembly will be painted. The paint builds up to .004" on the show surfaces. How can I model this paint build up? I want to have the paint model parametrically linked to the assembly so that it will change if any single component dimentsion changes. I tried making a sketch in the assembly based entirely from the assembly model edges. I then saved this sketch to a file. I was then going to make a thickened shell part from this saved sketch and then assemble it into the main assembly. The problem is that the saved sketch does not update as the assembly model geometry changes and thus my "paint" component is not linked to the assembly. Thanks for any suggestions.
 
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With all due respect, I am trying to see the value of modeling paint. I believe it's proper to account for that in your mass properties analysis. I think it's like modeling thread lubricant or axle lub [bugeyed]

Best Regards,

Heckler
Sr. Mechanical Engineer
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(In reference to David Beckham) "He can't kick with his left foot, he can't tackle, he can't head the ball and he doesn't score many goals. Apart from that, he'
 
If you're trying to approximate how much paint you will need to cover certain surfaces and you have behavioural modeling, you can make a copy of the surfaces to be painted (select the surfaces, then edit->copy and edit->paste) to create a quilt and make an analysis feature to measure the area, and finally another relation analysis feature to multiply it by your thickness. This should give you parameter which is a reasonable approximation of how much paint you will need.

Happy new years to all! I haven't been around much lately because I've been (fortunately) swamped with work :)
 
The purpose that I have for modeling paint is to show the correct dimensions in my final outline (customer) drawing. The entire assembly is painted and the paint can build up the width of the part by as much as .008" (.004" per side). When I show my dimensions in my final drawing I don't want to fake them. The .008" is a considerably increase on the width, so I need to account for this in the dimensioning. Our company is very strict about using only actual dimensions in drawings, so that they will update in case another person makes a change down the road.
 
That's a pretty small part where .008" is a 'considerable increase'. But in the interest of helping out, we use to have notes on all our fab drawings that indicated all part dimensions were 'finished dimensions'.

So if you send a part drawing to the manufacturer that indicates a width of .100" and you spec a .004" paint thickness, then it's up to the shop to build the part .092" wide so the finished width is within spec.

Our models were physically dimensioned .100" which already accommodated the paint thickness.

<tg>
 
I understand what telecomguy is saying but that won't work in my situation. My assembly is made up of 4 different parts that will affect the assembly thickness. All 4 of these parts are purchased items that are bought without the paint. We assemble in house and then paint the finished assembly. I need the individual part drawings to show the dimensions without paint, only the final assembly drawing needs to show the additional thickness. If my unpainted parts add up in the assembly to make the assembly thickness .100 +/-.005 without paint, then with paint it becomes .108 +/-.007 for example. The paint adds a .004 +/-.001 to each side. I can't make my dimensions in the drawing to be the correct .108 +/-.007 without overriding the true shown dimensions.
 
OK, now I see. It appears you may have to introduce your company to something new. You could create a relation in the assembly that is the sum of the various width dimensions. Something like this: assy_width=d10:0+d4:1+d6:2+2*paint_thickness

Then, change the overall width dimension using the override: @O&assy_width

You will have to argue the point that this is a true dimension that updates with model changes versus the alternative where you 'fake' the dimension.

<tg>
 

I don't understand the logic or application and
think it's opening a can of worms, but given the
desire to model painted and unpainted versions I
think I'd look at something like ...
_ Create references on unpainted surfaces.
_ Pick a (assumed 'solid') part face, RMB, Solid Surfs.
_ Edit -> Offset -> Expand Feature and enter the offset
value.
_ Go back and cut the 'paint' off where req'd.

Some variation on the (quilt building and offset based)
theme and family table or extern geom reference should
get you where you want to be.

 
Brad82
It is late in the day but here goes....

Whenever there is assembly operation, we produce it at the assembly level. So, in your case, assemble the painted surfaces as components. This way you can treat the painted surfaces as "real" geometry. Also, you can colour the surfaces to be obvious in the assembly.
If you are worried about parametric updates, make dependant copies of your parts, then add the paint thickness to the copied parts. Then cut away all but the painted surface and you have a parametric paint layer that can be suppressed at any time.
There may be more sophisticated ways to do this however, with Pro/E 2001 foundation, this is likely what I would try.

Cheers,

JW
 
Thanks to everyone on their responses. ttx-I thought about adding the surfaces and that should work, but I have quite a few tapped and c'bored holes that I would have to cutout of the paint components so they are not hidden.

jeff4136 - I tried your idea with the offset. I highlighted a surface then went to the pull down menu, but the "offset" feature was grayed out. I think that the offset only works in part files, but I maybe missing something.

telecomguy - I like your idea of setting up a relation. I think that my company would go for that. It will update the thickness automatically in the drawing if one part increases, so I don't see a foul with that.
 
telecomguy - I tried the relation idea. It worked with one snag. Wildfire would not show the value of the relation within the dimension. In other words the dimension properties, could not be modified with any other variable value besides the true one. My work around was to just blank out the dimension value. Then I added a note with the relation name and slid it beside the dimension arrows.
 
Sounds like you have a fix, but I was just wondering, could you not use family tables to create a painted and unpainted version of each part?

Dimension the unpainted version, but assemble the painted version...
 
Family table is what I was thinking also. We use it to show machined and unmachined versions of castings.

David
 
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