Another one. What would be the best way to get the bend

Rhino Rhino for Windows
1

I know there are probably several ways to model this. My thought is model a rectangular object from a side profile with the bend there. Then boolean difference/trim/cut to get the opening and shape. Are there other methods?

back
back1090Ă—1049 95.8 KB

back.stl (106.4 KB)

2

Is the cutout in the bent part? How would the part be made? Should sides be pependicular to the faces If so then create one bent surface, unroll that surface. Place flat version of cutout curve on the unrolled surface. Flow the curve onto the bent surface. Trim the bent surface. Offset the trimmed surface.

3

I used to make a decent living doing this type of stuff for a client before my McTenure here-

extract the main surfaces of the mesh and join them…

then dup the border-

then clean up the curves (rebuild, redraw circles and arcs with 3pt curves and circles)

make planar surfaces and loft them together, wirecut as needed for holes-

image
image930Ă—636 67.5 KB

file attached-

back_kfix.3dm (330.3 KB)

4

It looks like the cutout starts at the end of the bend.

3D Print

Sides are perpendicular.

I’ve only used the unroll and flow once some years ago in a Rhino Class. I’ll have to looks into those features again.

5

Thanks, Kyle. However, I don’t know how to extract surfaces in a mesh.

6

simply explode the mesh.

of shift+ctrl+ click to sub object select individual faces, which you can then delete or transform as needed.

7

Duh. I think I remember exploding once, and I got a million separate faces. That’s what made me forever abandon working from meshes. I just exploded as you did, and it is all usable parts. Thanks.

8

you can always select faces (lasso is useful for this) and join to make groups of faces

there are also some specialized extract tools mesh>edit tools>extract

you can extract by area, angle, connected faces with an angle tolerance etc…

9

To rebuild the noted area, what tool? This line is in multiple directions. (G2,G3? I don’t know)

outline
outline1434Ă—1069 20.8 KB

10

IMO there are a couple of ways to do it,

  1. snap a edit point curve to the ends and vertices of the original mesh (most accurate)

  2. (what I did) use blendcrv and adjust to visually get as close as possible to the input mesh.

  3. dupedge the edges from the original mesh, join the resulting curves into one polycurve and then rebuild, then match the rebuilt curve to the surrounding curves.

11
  1. Curve first approach
    1. Forget for a moment about the smooth transition from one plane to the other, and create a set of curves on one plane, then another set on another plane. At this point you have a sharp corner
    2. Trim the curves on each plane, removing the part near the sharp corner
    3. Join the curves with a smooth transition curve
    4. Create the surface
  2. Surface first approach
    1. Create the side view curve
    2. Extrude it and create one surface with the bend exactly the way you want it
    3. Create the curves on one plane
    4. Project them on the surface
    5. Trim the surface with those curves
12

Thanks to all for the help. I don’t understand some of it as I’ve forgotten a lot of the terms. e.g. “edit point curve.” I have to look that up. Anyway, I used some of the ideas and used commands I remembered, like “project.” I’m sure what I’ve done is not totally accurate, but it should work for hobbyist 3D printing tolerances. I still have never learned how to do material application at all.

Gracias

Shaded
Shaded1105Ă—1017 105 KB

Rendered
Rendered943Ă—968 279 KB