Hopper with non parallels discharge and inlets

[benbrowning]

Anybody else having trouble with this? I have two rectangular sketches on non parallel planes. it will make a loft when 3d model then I extrude to make the top and bottom flanges but when i go to put formed sheet metal around the form two of the sides are fine but two of them are... twisted or not flat or something no matter I try I can't get it to work. Any suggestions?

[cadman777 · Accepted solution]

I just tested your STEP file for flat surfaces.

You can do this test by trying to place a WorkPlain on each surface.

If it doesn't work, then your surface is not flat.

The way you fix non-planar surfaces is by using TRIANGLES.

In other words, split that polygon into triangles, so you can bend that surface along the crease.

You can make your crease from top corner to opposite side bottom corner.

I've done this many times over the years making hoppers and chutes.

TRIANGLES are the simplest solution to non-planar features that need to become sheetmetal parts.

Find attached your file w/one of the sides fixed. The top edge had a problem (maybe it wasn't perfectly straight?), so I deleted it and used a line to make up that edge. Anyway, you can see how I did this using a 3d sketch and making surfaces from it.

Remember: You want to use ONLY 2 EDGES to make a flat surface. If one or both of the other edges are not planar, then you need to decide which edges to use to make your planar surface, and which edges to re-work or separate into another triangular plane.

If you want to make a sheetmetal part from the 2 adjoining triangular surfaces, then you Stitch them together and then thicken them. Hope this helps...

[benbrowning]

That makes sense. When i tried it as a sheet metal lofted flange it actually had those triangle in those sides. It just seems like it would be flat but I understand now why it’s not. Thanks a bunch. I’ll wrestle with that for a while.

[JDMather]

Where is Sketch2 (location in space)?

(I see several issues with this sketch.)

Where do you want your Rips?

How many panels (individual parts) do you want? 1, 3, other?

Fix Sketch2 and then Attach your new file here.

[benbrowning]

Sketch two I made an offset plate parallel to xy plate. Then drew a line on that plane. Then rotated a new plane a certain amount around that line. Then drew rectangle sketch two. I made loft between that rect and rect on xy plane. After that I added the extrusions top and bottom that will be angle flanges bent into each wall.

[JDMather]

You don't have to explain to me what you did - I can open the file and see that you do not know where Sketch2 is in space.

What do you observe it you click and drag the lines in Sketch2?

[benbrowning]

yes the sketch did have some issues. sorry I sent the wrong version. Breaking the non flat sides into rectangles fixed the problem, takes a little extra time but it works. thanks for your time. 

[benbrowning]

Worked out like a charm , just a little extra work. thanks for the help. 

[cadman777]

You're welcome.

Glad it worked!

Incidentally, I rarely use 3d sketches b/c they tend to have issues down stream in complicated projects.

So remember to use them with caution, like use a 2d sketch any time you can and use a 3d sketch when you absolutely must b/c you can't use a 2d sketch. Everybody has their own experiences w/how and when to use them.