Bend Lines on Drawings for Finger Brakes
 

We have a finger brake:
http://www.use-enco.com/CGI/INSRIT?P...PMAKA=130-5061

We use SolidWorks for our modeling/drawing. When doing sheet metal drawings SolidWorks puts the bend lines at the tangent line rather than where the edge of the fingers should be. Having the students line up the fingers on the lines showing on the drawing will be incorrect.

Has anyone been able to figure out how to produce drawings that show where the edges of the fingers should be placed on the sheet of metal to be bent, either from SolidWorks or other CAD packages?

Thank you for your help!

Re: Bend Lines on Drawings for Finger Brakes
 

I think you need to unfold the part and make a flat drawing with dimensions to bend lines. The bend lines are in the center of the bend on flat drawing.

Hope this helps

Re: Bend Lines on Drawings for Finger Brakes
 

Well, I guess the first question is what bend radii are you using? If you have a sharp bend, it's all good. As you increase the bend radius and the bending nose radius, the tangent line is where the end of the clamping action is. For FRC, I prefer to have sharp interior corners for the simplicity of manufacture, but in my day job, I prefer to indicate to the fabricator what I want the final part to look like and have them figure it out based on their equipment. In the one case, I clamp at the interior corner; in the other, I just get the part I'm looking for from someone else :D .

From looking at the Enco website, you may want to manually add the bend lines on the flat pattern print (along with a note "BEND UP" or "BEND DOWN") in SolidWorks. Make a few test pieces (1" wide by 10" long or so) and bend them to determine what offset you need from the tangent to get the bend you want for the material and thickness you're working with. That would probably be the easiest way.

Of course, the question then becomes, how accurate do you need the parts to be? Having worked in an industrial sheet metal plant making filing cabinets, I can say that the automated systems we used (custom-built presses & formers) were accurate and repeatable to 1/32". If you make the design have some "slop" to account for potential variation in the sheet metal part, then you are a little more free to work on things.

Another option (long post) would be to find a local fabricator or such and see what advice they can give you.