Sheet metal driving me round the bend...

[Markaj]

...haha
It's been the bane of my life for the last couple of years & not just Alibre though (inventor is as bad)!
Anyway, can anyone shed some light on this; If I change the material thickness from 1.6 to 1.2 the flanges fail & I don't understand why they should. No other settings change.
Sometimes if the wind is blowing in the right direction you can delete & redo them & it works, sometimes it doesn't. Usually I end up remodelling the part completely as it's the quickest fix - so much for parametric modelling.
Like most of these snags, it would be nice to know what to avoid to prevent this happening, as it is a colossal waste of time & an unecessary stressout trying to fix what should be a two minute job. Plus it doesn't do your professional credibility much good either!

 

[Markaj]

Here's a wierd thing;
change the material to 1.3 & it works, 1.2 fails, 1.22 works, 1.1 partly fails, 1.19 partly fails, 1.18 is ok.................(& its just the flanges I'm bothered with)
hmmmm

 

[jhiker]

Here's a wierd thing;
change the material to 1.3 & it works, 1.2 fails, 1.22 works, 1.1 partly fails, 1.19 partly fails, 1.18 is ok.................(& its just the flanges I'm bothered with)
hmmmm

I'm afraid I can't offer a solution. It seems strange that all but the flange at 135deg fail. However, it will allow you to create new flanges where the old ones were!

 

[OTE_TheMissile]

I'm not sure if it's the root of the problem, but looking in the Equation Editor you have a bunch of parameters linked to dimensions that no longer exist (equations show up in red text). Almost like you chained a bunch of features to an original feature and then went back and deleted/replaced that original.

Although when I went to open it, Alibre warned me I was missing a Global Parameters file, so maybe that's all that is. I haven't messed with Global Parameters myself yet TBH.



But yeah, I've never enjoyed doing Sheetmetal work, and we do plenty of it at my shop. It's become something of a running gag, "Have I mentioned lately how much I hate Sheetmetal CAD?"

 

[Markaj]

Hmm - I did actually remove all the global parameters & replace them with numbers just for the version I posted here. However both versions behave exactly the same for me.
Its just the changing the thickness that causes the fails.
Altering the gauge by .01mm at a time until it behaves seems the quickest fix.
But yes - its an uphill struggle, & has a high wind-up factor!
I'd be curious to know what the most effective SM software is if such a thing exists.......or maybe there is an opportunity there.

 

[Lew_Merrick]

It's been the bane of my life for the last couple of years & not just Alibre though (inventor is as bad)!

If you are using a "Gloal Parameters File" (which should be called a "Project Variables File") you need to "Package" your file to upload it properly. More to the point the "K Factor" is noise created by those with no background in sheetmetal forming (says somebody with a formal Journeyman's rating as a Tool & Die Machinist). The attached spreadsheet may aid you... -- Lew

 

[idslk]

Hello Markaj,

if you use outside instead of inside Alignment

and do the "doorwidth" correction (material thickness) by yourself inside the EquationEditor
you can make it work with every sheetmetalthickness.



Not so convinent like the outside orientation, but the results are correct.
You can also calculate the length of the 45° flange...
I doesn't made the file look good enough to be ready to go, so it's not appended...
If you want to use the inside option for your side flanges, you should send it to the support i think.

Regards
Stefan