Sheet Metal - mating flange edges & releifs - how to?

[wogz]

OK, So I do a lot of sheet metal. And I’ve been at Pro E for about a year now. One thing eludes me, and it’s time to tackle the issue.

I want to make a box (a base & 4 sides), with nice walls and the flange edges that come together equally, so I can run a fillet weld down the seam. The flanges mate at their inside edges, no overlaps, gaps, or anything, just inside edge to inside edge. A relief of some sort at the corners would be nice too..

Here’s the crux: I can’t seem to get the flanges to behave as I want.

So, to start.. I make a flat, a simple rectangle. I add a flange wall / flat wall to one edge, say the long edge. I then ad another flange to the next edge. Now, the 1st flange is the full length of the flat. The 2nd flange is inside the bend radius of the 1st bend. The 1st bend's radius runs the entire length. the 2nd flange essentially rips at the start of the 2st bend's radius. (I want to eliminate this)

What I want to do, is add a relief, but more importantly, have the flange inside edges come together, not overlap. (The inner edge of one flange is essentially touching the perpendicular inside edge of the next) I want each flange edge to be flush with the next flange’s inside face. Or, another way: I’d like the first flange’s edge to be pulled back, matching the inside face of the 2nd flange. And the 2nd flange’s edge to match the inside face of the 1st flange. This will give me a nice corner to run a fillet weld in.

I’ve clicked on the corner relief icon, and I get the dialog box. I’ve followed the PTC univ course on corner relief and I get what they are saying, but it doesn't seem to do anything.. (Their example seems to start from a flat pattern..) Actually, I can’t seem to do anything with flanges mating to their neighbour. (we all seem to live with it here) I’ve tried using the ‘extend’ command, but it only seems to work on one flange (it won’t do the same on flange #2), and I get a weird overhang of material at the bend & corner. No relief, just a mass of metal. I can then add an extra 0° flange extended from the 2nd flange, but that seems overly complicated to get what I want (and I still have this ugly twisted mass of metal in the corner!, if it unfolds at all at this point!)

I don't want to start with a solid extruded rectangle / shape each & every time. I want the ease to add & remove flanges at my leisure, depending how the design develops..

Am I missing something? It shouldn’t be this complicated, should it?

 

[wogz]

KK, panic over. I think I've found it, and why it's not working correctly (or was!) Accuracy set too low (or too high?!)..

got my edges, got my reliefs, and got my box done.. All with flange wall, and various setting. After spending most of the afternoon playing with the various options, nothing seemed to work, until I changed the accuracy setting.

 

[magnusod]

It's easier if after the flat simple rectangle use flange wall directly and select all edges. Start by selecting one edge, hold down shift button and select main surface. You will then get a surface lopp selecting all edges. Select Flange wall and you will get all four walls in one feature and it's easier to control the reliefs.

Another option is to create a box in standard mode and then enter sheetmetal, shell part and use conversion feature to rip corner edges.

 

[wogz]

Thanks for the input. While I do most of that, I do run into issues when my box isn't a standard 90° x 90° x 90° box. I find any edge that isn't 90° to it's neighbour, Pro E / Creo seems to choke.. Any ideas on how to better control edge to edge seams? Get a better over / under / under / over overlap on adjoining flanges.

Any idea to better control how the edges meet?

 

[srieger]

Sometimes you can use the extend and then flatten it, add material and bend back. I do a lot of sheetmetal and it can be a bit temperamental with more complicated geometry. You can also create it as a solid, shell it and add rips. But, that can sometimes get a bit difficult to unfold.