Incrementally Dimensioning Sheet Metal Flat Pattern For Bending

[Lukeofalltrades15]

Greetings all,

I regularly use Fusion's sheet metal tools, and perhaps I'm just missing something simple here, or maybe my workflow is just bad. Any insight would be invaluable to me.

My company has a CNC plasma table and semi CNC press brake in-house which I primarily operate (I'm also the only one engineering). When I create a drawing of my flat pattern and I'm adding bend center-line dimensions in order to set the machines back-gauge I'm having a bit of confusion when trying to create dimensions for parts with multiple bends. For many parts I must bump an edge, which has already been folded, to my back-gauge in order to perform the second bend. My issue is there does not appear to be a good way to get an accurate reference for the second bend center-line in relation to the outside edge created from the first bend (at least working off of the flat pattern). 

In the first image here I will be bending 2 first, then 3, and lastly 1. This order of operations is critical due to tooling limitations. The dimension from outside bend line on bend 3 to the center of bend 1 is shown as 2.013in, but if I unfold the same part in the design workspace and pull a measurement via a sketch from the center of bend 1 to the edge of bend 3 the dimension shows as 1.869. There's no way to unfold a sheet metal part partially in the drawing workspace in order to dimension the part in the way I am intending (almost showing the bending process in stages, 1, 2,3, ect.).

When actually performing the bends in the press brake I have found that the part comes out correctly using the dimension I have pulled in the design workspace, not the one referenced off of the outer bend line on the flat pattern. This is incredibly annoying because for documentation purposes it means I have to hop between work-spaces and manually change the dimension shown on the sheet to what I've measured off of the model. It's obviously even more annoying when the part has more bends and details.

Is there a simpler way? Or am I perhaps doing something wrong on the sheet metal rule end? I've painstakingly made test bends with multiple sets of tooling to generate a sheet metal rule library for different material thicknesses, die combinations, and material types in order to get the results I want, I just wish the drawing side had a bit more to offer for manipulating sheet metal parts. 

[TheCADWhisperer]

@Lukeofalltrades15 

In your image you dimensioned between a bend centerline and a bend extant rather than between the two bend centerlines.

Is this what you intended to do?

[Lukeofalltrades15]

Yes, knowing the center to center distance does not help when actually trying to set the machine up for bending, I need the dimension from the outside edge of the first bend (after it is bent) to the center-line of the second bend. You can see here a bit better what I'm talking about. Please forgive the potato camera quality.

 

[jhackney1972 · Accepted solution]

Using the Unfold command, you can make partial sheet metal body unfolds.  This command allows you to select one of more bends you desire.  You can then add a manual bend line easily with a simple sketch.  You then save them out as individual files.  You can them assembly them into an assembly and add dimensions from a common edge.  This process is not easy but it does what you asked, partial unfolds.  Below is a simple sheet metal piece with the an drawing example.

[Lukeofalltrades15]

I see what you’re saying. I knew I could use the unfold command in the design workspace, it just seems to me like the drawing workspace could really benefit from having a similar command, or a way to add a partially unfolded piece to a drawing sheet like there is for flat patterns. In the particular instance I’m in I cannot reference off of a common edge as you have shown because there are features there stopping me from bumping that edge to the back-gauge, I need to reference off of the folded edge. I could absolutely still do this using the workflow you’ve laid out as well, it just seems… tedious.