Multi Flange Part in sheet Metal

[Jeff Coggins]

Can anyone tell me what is going on with this part. Sometimes it will unfold and sometimes not. I've had similar problems with other mutiflange parts. With this part I've gotten several error messages, one was a corrupt memory and the other was some type of exception error.

[NateLiqGrav]

I'm not sure why they are not coming out right in the 'Flat Pattern', but I found that they worked right if you just do an 'Unbend instead. You could put that feature as a separate configuration.

[HaroldL]

Jeff,
This seems to be an ongoing problem with Alibre sheet metal, it has serious issues with complex formed parts. I had one similar to this, though not as many bends, and it gave similar errors. We can only hope that after the v12 release they get real serious about the sheet metal module for Alibre. Until then we have to kludge our way through issues like this.
I found that by rolling your part back and toggling the Flat Pattern on for each bend as I rolled forward that at Flange <15> it would give the following errors:

Memory error.jpg (14.08 KB) Viewed 696 times

I also noticed that on all the bends for the flanges on the transition from the outside ring to the inside ring there was an untrimmed portion. This can be eliminated by changing the bend alignment from inside to outside or by checking the Trim Side Bends option on. Unfortunately making one or both of these changes did not stop the part from failing to flatten.

I also found that, as Nate suggested, inserting an Unbend at the end that Flange <51> through Flange <55> failed to unbend the the proper direction. So more than one Unbend would be required to get the whole part flattened.

If you haven't already done so, submit this to Alibre support to see what they have to say about it.

H.
v11.1

[Jeff Coggins]

Thanks for all the input. I convinced my boss to buy Alibre so I could use the sheet metal section. With all the promblems I have with some parts, he's getting really ticked off at the software. I downloaded and installed ver 11.2 which addressed some issues with multi flanged parts . But still getting promblems like the memory error showed in these replies. If Alibre dosn't get the sheet metal up to snuff soon, I'll be forced to go to another program. I really like Alibre and it ease of use and can overcome most prombles with work arounds. But I have a lot of time constrants on progects and not much time to figure out the work arounds. I've submitted several promblem parts to Alibre, but with there work load, I usaually find a fix before they can get back to me. So life gos on.

[HaroldL]

On what factors/functions did you convince your boss to purchase Alibre? It wasn't solely on sheet metal, was it?

I think Alibre has its attention focused on v12 right now so don't expect any improvements or enhancements to the sheet metal module. In my opinion I think they added sheet metal as an after thought. Certainly before it was ready. For "simple" sheet metal parts it does fine, but if you need to create "complex" parts, like your Bullnose part, I think you could do better than using Alibre sheet metal. (Heck, you could probably layout the part in 2D faster than creating it in Alibre.)

It seems like, if you have a machined, molded or cast part, Alibre does a good job. They just aren't that focused on sheet metal. They herald the fact, in the Alibre store, that it is "Created in a partnership with Amada Corporation, the world’s largest sheet metal machinery company" and that it "was programmed to fit the needs and demands of real-world production". Yet it is missing many tools and features that are required to do "real-world" parts. Look at the list of enhancements that have been submitted and have yet to be implemented and you begin to wonder if there is any serious consideration to sheet metal. Louvers, sketched bends, multiple bends in one step, offset forms, lance forms, additions to the Shape tool list to include keyway, keyhole, quad-D's, etc. I could go on but I think you get the idea. In short, while Alibre now does sheet metal, I don't think it does it to "real-world" standards, yet. If I were asked defend Alibre sheet metal for a production environment I don't think I could, at least not now in it's current state.

Sorry for the rant, but your issue gave the opportunity.
H.
v11.2

[Jeff Coggins]

Thanks for all the input. As I've said earlier , I got Alibre just for the sheet metal section. Hopefully more people will complain and Alibre will get this section right.

[cherkey]

Sorry for the delay in post...I was able to unbend and flatten. I did see some weird stuff with flanges bending in on themselves.... had the best success when selecting a flange more towards the middle of the part as the Fixed Face.
Definitely do Trim Side Bends. Doing that seemed to cure the flanges bending in on themselves...

[dudley]

Here's my attempt at this. I create a tab, cut the tab, pattern the cut, pattern the tab, then add the flanges. Note that I use AD_BendReliefDepth and AD_Thickness in the tab sketch dimension so that the OD and ID end up being 3.5 inches and 2.5 inches (or reasonably close), respectively. The cuts in the tab provide bend relief. The cut at the bottom of the tab is a slot so that I can use the "Match Taper" option when creating the ID flanges. I'm not a sheet metal guy so if this isn't helpful, I apologize in advance.