How do you get a surface to follow a bend?

[bhayden]

I've got a flex-circuit that I've modeled as a sheetmetal part. I'd like to add surfaces to show pads and traces. I did an unbend all to flatten the model and then drew in a surface that crossed two bend lines. When I unbend all the surface remains flat. Is there a way to apply one surface around bends?



View attachment 26



Also, you can see the round pads at the bottom look crisp and clear whereas the square pads at the top are washed out with the surface of the part. The round pads are floating .005 off the surface of the part. Is there a better way to accomplish this effect?



Bernie Hayden

XKL LLC

 

[gggggggggg]

here is a wiz bang of an idea.



forget the floating surface idea. if this model was ever used in a manufacturing program, you'd been pulling your hair out.



i suggest creating a projected datum curve onto all the surfaces you need to see the pad on.



or, if the resulting dimesions of the newly drawn curve are important, you will need to use the formed datum curve option.

 

[miked]

If the two surfaces are co planar there is no way that I know to make them look good. Unfortunately the offset is the easiest method.

Mike

 

[bhayden]

> forget the floating surface idea. if this model was

> ever used in a manufacturing program, you'd been

> pulling your hair out.



This model will NEVER be used for manufacturing. All EE design is done by a separate department and in a CAD system that is totally uncompatable with any other system know to man. The idea is to present a mechanical solution to a problem. Unless the idea is easy to visualize the adoption of a new (for us)

technology will never get off the ground. The circuit is only shown to demonstrate how a high current path (50 amps) can be achieved using only mechanical connections to the main PCB.



> i suggest creating a projected datum curve onto

> all the surfaces you need to see the pad on.



I'll hunt around for this function. I have very little experience with surfaces since it's not generally relevant to brake formed sheetmetal. I guess even less so since the weak sheetmetal module is incapable of forming a surface.



> or, if the resulting dimesions of the newly drawn curve

> are important, you will need to use the formed datum

> curve option.



The actual dimensions are not at all critical. If fact they will only be tweaked to look good. But I guess I'll end up having to learn the difference anyway if I want to use surfaces.





> If the two surfaces are co planar there is no way that I

> know to make them look good. Unfortunately the offset

> is the easiest method



The alternate to surfaces, and what I've done in the past, is to create a small raised protrusion. This just seems silly for a cosmetic feature but it might still be the easiest work around. My limited exposure to surfaces as also lead to problems in creating isometric views. I've had to hide the surface geometry to get the view to display correctly which is an increadable pain in the ass since I can find no way to save the hide status of a feature in either the .PRT or .DRG file.



-Bernie-

 

[miked]

I doubt this is something that dougr would want to hear.... in wildfire the hide status is saved.

Cant you create a layer and dump them on it for now?

Mike

 

[Brian_Adkins]

If these features are purely cosmetic to represent what the traces might look like, I'd stick with surfaces and offset them slightly from the main part. You can use an offset surface feature to create a complete offset of the entire part. Then you could create projected datum curves onto that surface. Finally, use that curve to trim away the surface that you don't want.



As far as getting your drawing view to look right with surfaces, try the Quilt HLR option in the view-display menu to make surface geoemtry display just like solids (with hidden lines removed).



-Brian

 

[dougr]

You may also want to improve the quality of your shading:



VIEW/DISPLAY SETTINGS/MODEL DISPLAY/SHADE



Default is 3, 12 is max..

 

[bhayden]

dougr



Tried improving the quality of shading. MAX for me was 10, not 12. Maybe because I've disabled OpenGL? Anyway, it made abosolutely no difference to the display as far as I could tell; go figure. Perhaps there's one of those other obsure things you have to enable to see a result.



-Bernie-

 

[dougr]

Think you're right, 10 is max..

 

[chesterman]

I may be misunderstanding you situation, but why can't you continue to use the tiny protusions like you have been. Create a family table member that includes the pads and one that doesn't. Then reference the one without in your drawing, instead of trying to hide it. Both members stay related to the drawing and to each other.

 

[Brian_Adkins]

Tiny protrusions don't work on sheetmetal parts (as far as I know).



-Brian

 

[gggggggggg]

here is another solution.



extrude a surface along the profile of your part (i.e. side view) then trim the surface using an extruded cut trim, in which the section is the shape of your pad. this will give you exactly the surface you want, but i don't know what to do about the poor shading problem.



let me know if this explanation is unclear to you, i'd be happy to help. i think this will be the solution you are looking for.

 

[bhayden]

> Tiny protrusions don't work on sheetmetal parts (as far > as I know).



Brian,



You appear to be 100% correct. In the past the parts I'd used the tiny protrusions (or cuts) to create a cosmetic feature were standard solids, not sheetmetal parts. The protrusion option when in the sheetmetal modul only allows you to define shape, not depth. If you sketch something on a sheetmetal surface the resultant protrusion is totally embedded in the part.



And thanks for reminding me about the Quilt HLR option. I've used that to get imported IGES models to display correctly. It didn't occur to me that that's what I needed to use to deal with surfaces.



gggggggggg,



I think I understand what you're suggesting. If I understand right it's about the same thing Brian suggested in first creating an offset surface of the entire part. Except your method would leave the surfaces coplanar which it appears will not produce an adaquate shaded image.



-Bernie

 

[jperkins]

Do the part as a solid and add a small protrusion for the pads or even a small cut. Then change the color of the surface.

Making the part in sheetmetal doesn't buy you anything because they are not manufactured in the flat and then bent.



Developed length doesn't apply because it is an assembly. If you manufacture it in the flat and bend it will most likely delaminate. A flex circuit is plastic and copper foil at different layers. Some are conductive ink on plastic.



You can make the parts in sheetmetal, change the color of each part and then make an assembly.



Also in sheetmetal if you add a feature in the flat it doesn't always follow the part when you do a bend back.



jperkins

 

[bhayden]

>Making the part in sheetmetal doesn't buy you anything >because they are not manufactured in the flat and then >bent.



I didn't realize flex-circuits weren't made in the flat. However, I didn't start it as a sheetmetal project of manufacturing reasons. The real design will be done by the sparkies anyway :+) The reason for experimenting with the sheetmetal module were two fold (pardon the pun). First I naively thought that a surface applied in the flat would bend up with the part. As I've learned even solid protrusions do not follow bends. The other reason for using sheetmetal was to be able to adjust thickness. Since this is such a simple shape modeling it as a thin extruded solid works just fine for this and would be a much better technique.



The final model will have to be an assembly to show connectors. It might make sense to put the structure and the circuit in different .prt models. Have to think about that one.



-Bernie-