What method to bend this pear shaped sheet of metal?

[Steve1]

Hi,
V5
I have never had any succes with cage bending, and suddenly need to get this done as deadline upon me now, oooh eck !
Can anyone please just bend it and post the V5 result.

and say or show in a printcsreen how its done ?

obviously it must start to bend gently beyond the nut, as not shown here its pressing against a flat surface, nut done up tight ! measuring up from that surface, ‘A’ was 0.28 up. My dims dont mean ‘A’ must stretch to reach new ‘A’ just must be 0.28 up when done !

its a see it done not text, but I need it as a .3dm for V5 if poss pleeese.

and I promise to sit down and go through all the cage editing vids afterwards.

I often have to bend sheet metal, and have extruded the shapes but if I extrude it wont be the same as taking the real shape and bending it.

Bestway bend.3dm (72.6 KB)

Steve

[davidcockey]

Trying to start with a flat shape and bend it to a desired shape is difficult in Rhino.

My recommendation:
Draw the center section of the shape with thickness you want as a curve in the left view.
Decide where the neutral surface is in the thickness and draw a curve representing the neutral surface.
Adjust you design until the neutral surface has the desired length.
Extrude the neutral surface curve.
Unroll the neutral surface.
Draw the desired shape of the flat part on the unrolled surface.
FlowAlongSrf the desired shape curve onto the extruded neutral surface.
Trim the neutral surface with the flowed curve.
Extrude the trimmed neutral surface.

[eons]

Is this what you mean? I used Transform->Bend with the spine as just the ‘loose’ segment.
I’d save Cage Edit for complex distortions.
Bestway bend_bent.3dm (1.8 MB)

[eons]

…or do you mean like this? Transform->Flow along curve. I had to make an original curve and a bent curve and use the circle to ensure they’re the same length (Flow will stretch to make it fit).
Bestway bend_bent2.3dm (1.9 MB)

[Steve1]

Hi,
V5,
Thanks David,
will try to follow that method.

Eons, thanks.
actually a mix of the two, a gentle curve immediate after bolt head then straight thereafter,

and the outer tip (A) to be 0.28 and not beyond. so both go beyond and need to come back a bit.

here are images of it.

So how to do that ?

Cheers

Steve

[eons]

Adjust the ‘bend’ curve to suit (here with a looser bend),

Transform->Flow along curve, select the plate then the original (straight) line then the new (bend) line:

Bestway bend_bent3.3dm (1.9 MB)

[encephalon]

explode and use one surface, split above the nut, rotate, FilletSrf, join, OffsetSrf.

[Steve1]

Thanks David, Eons and Encephalon for your methods, all make sense.
I will do each and see which has potential for other bends as well as this one.

The FilletSrf is new to me, the Eons method rings a bell.
Cage Edit is best avoided then.

Meanwhile I will use the bend3 as its ready to go and clock ticking.
Use for the presentation then more time perhaps to revisit this project but after 8 weeks and I only had 3 for it, its wrecked other work. a screw thread being a major bug in the ointment.

Many Thanks indeed…saved the day

Steve