Sheet metal

joseph_terpend

2 Things I would like to be able to do  in ONshape. Sheet metal Cylinders and square to round sheet metal lofts.

lougallo

@joseph_terpend We are working on it.  To post this as an improvement for voting it must be one feature per post.

lana

@joseph_terpend
Square to round is not a developable surface, so strictly speaking, is not a sheet metal functionality. How do you use it?  What really happens when it is being manufactured?

brucebartlett

@lana I think this is what the OP means for round to square (sheet metal lofts), a very common requirement for sheet metal ducting work, same as this post  https://forum.onshape.com/discussion/comment/30265#Comment_30265

Using a roll form machine in sheet metal is also very common, the simplest form is a cylinder but shapes can also be made with varying radi and I have the need to the incorporate this with sheet metal bends. Here's an example of a part I'd like to unfold with rolls and bends.  

lana

@brucebartlett
Thank you for your example. This one I understand - all the surfaces here are either plane or rolled + bends between them. It is clear how to unfold them into a flat. In case of arc to line loft there is no clear unfolding rule. I'd like to understand manufacturing process for such a model in order to choose the best approximation for unfolding. Your answer in the other thread suggests a possible approach: approximating loft with piece-wise flat surface. This would nicely correspond to a multiple bends manufacturing process.  I'd like to understand if this is the manufacturing process normally used for such models.

NeilCooke

https://cad.onshape.com/documents/4568b85540f412a1f22da289/w/cc3c3dd219f1c74a573057e6/e/7b22bfc4ec622f78c095a23e

Nickolas_Lockard

It's February 2023. Why is sheet metal still so crappy? It pretty much never works. I have a simple solid that's obviously sheet metal compatible, but it says 'it's not a solid.' Yes, it is! Please improve this feature. It's substandard.

glen_dewsbury

@lana
I've done this in the past manually as an approximation. It takes a lot of steps to accomplish. There is also a bit of fudging involved in cleaning up ends. Notice that each bend is a different angle. When bent on a break it will stretch enough to come out looking pretty good and will fit well. OS has difficulty anytime there is a need to overlap a bend or particularly where bends need a partial trim. I sure was pleased with Solid Edge being able to do an approximation some time back since I was doing a lot of these at the time. Used to get even more fuzzy when there was a need for floating liners offset 4 or 6" inside of the main casing.
More facets will make a closer approximation.
https://cad.onshape.com/documents/6a5c2de10f77d28fb601c807/w/7a62351c650a26704e6c30a2/e/6ec37f399d00551edfbcf861

bryan_lagrange

@glen_dewsbury we are having a user group meeting March 23rd on sheet metal. I am planning to have a segment where we can discuss items like this to get a focus on sheet metal improvements and possible current “work arounds”. 

glen_dewsbury

I plan to attend.

bryan_lagrange

We will see you there.

eric_pesty

@glen_dewsbury, @lana
You don't actually need so many steps: you can loft directly from lines to a point to create a planar surfaces that will work for sure with a "thicken" sheet metal:

EDIT: improved the model a bit, note that you can trim the corner of the surface before creating the sheet metal model to cleanup the corner. Using the polygon tool and box selection it's pretty quick to create such a model:
https://cad.onshape.com/documents/43ef7c2dd3d6ab133a50258b/w/c817829a385222a6fee70df5/e/69849f7270e935ecf6471a5b




I just scrolled up further and looked at @NeilCooke's example and that's actually pretty simple... the trick to thicken lofted sheet surfaces for sheet metal is making sure the faces are actually planar.