how do I apply curvature to flat object

Sorry, no bright ideas, but how the heck can you expect to deform a

600mm x 200mm PCB by 10% of its length and not cause solder failures everywhere? Is this th>

Good one. Hmmm.

Maybe you can figure out a way to use the deform feature in 04. Of course, this would deform all your componentes too, but not a lot. Maybe that would be tolerable?

Or maybe model the whole thing in the bent state, but apply all your extrusions using the wrap feature in 04. You would need a separate wrap for each type of component, representing all the components of that type, I suppose.

Just ideas. How accurate does your finished model have to be? How detailed?

Metalwork accurate -- better than deform is from early tests.

I would live with a thin feature that I could apply the curve to, and I would drill holes in it before applying the curvature, so I could find where those holes ended up after doing so. I can apply the components after curving the board, as long as I can carry through some kind of mark (point, hole etc) to show the position. The components with real height end up normal to the curve anyway -- they don't deform like the fiberglass does.

Fairly good. Even allowing elongated holes it has to be accurate within 1mm or so over 600mm

-- Regards, Gavin Melville snipped-for-privacy@acclipse.co.nz

As long as all components are "bent" across their short dimension we have no problem with it. The actual deflection is quite small -- the PCB fits on a 1.9m radius. We have tested them with far more curvature and even capacitors (probably the most delicate) have no problems.

Are the components applied as features or parts?

This method will work if it's OK if your holes are normal to the sketch plane rather than the curve:

1) draw your curved object and extrude it 2) create a plane which is normal to the curve at some convenient point (probably an end)

3) Use a little math--the dimension on the normal sketch plane is geometrically related to the dimension in the flat. The dimension is a function of the hole's angular distance from the normal that defines your plane

A little nomenclature: X is distance in the flat S is distance along the curve Theta is angle (in radians)

From geometry, we know the S=R*Theta, and X=R*sin(Theta).... doing a little algebra, we get: Theta=S/R (eqn 1) S/Theta=X/sin(Theta), or: X= S*sin(Theta)/Theta (eqn2)

For any given point, you know S & R Use eqn1 to calculate Theta Use eqn2 to calculate X dimension your hole (with value X) on the normal sketch plane

This method can be extended to apply to curvature on two axes.

PS--This'd be a great use of a design table....

oops--the sketch plane should be tangent, not normal....

Thanks Michael,

I had thought of that -- although I do have 91 objects to get the correct position for.. Still possible, just less fun than it looks.

Of course I really need to do this the other way around -- I have the flattened object, and want to get the curved one.

Have been experimenting with gentle bends in sheet metal objects -- it looks like it won't work. It would be really nice if I could flatten the part, make some changes, and bend it again.

snipped-for-privacy@acclipse.co.nz (Gavin Melville) wrote in news: snipped-for-privacy@posting.google.com:

I may be mis-understanding but....

If I create a flat sheet metal panel a little longer than I need (say .25" on each end in the direction of eventual curvature), punch all my holes in it and then use a sketched bend to get the curve I want, I then have my PCB curved with all its required holes dimensioned in the flat.

Then bring it into an assembly and add components.

Zander

Gavin, Have you tried the Deform feature in 2004? You can deform using an initial curve and a target curve and do it after all the feature are in the board. Perhaps, I'm barking up the wrong tree here, but sounds like what you want to do.