How to create internal tab forms

[JasonMorgan]

I want to create a form in sheetmetal where a U shapped section of the flat surface of the material is bent up 90 degrees. I create a bend line across the tops of the U, where the U is defined as a rip, but the bend can't form - why?



Im I doing this the right way, or is there a better way?



An example file would be appreciated



Regards,

J

 

[swcalvert]

Jason, how about a sketch to give us an idea of what you're talking about.



Steve C

 

[JasonMorgan]

Here is a sketch of what I want to create, done using a surface.



This one has two of the described U's end-to-end to create the final feature.



View attachment 331

 

[jperkins]

Jason,



First cutout the hole area and then attach a wall.



JP

 

[JasonMorgan]

This method has been suggested off forum already, but it does not solve the problem, it creates a visual model of the part, but not an engineering model.



This is because the size of the apperture is not linked to the size of the hole, less lost material in the cut (ideally none) and the material lost in the bend radius.



I've partially solved this by using an attached edge wall with radius, then un-bending and extending the edge of the (un)bent part to its adjacent wall, then bending back.



Now the tab size is related to the size of the hole, at least in the direction normal to the axis of the bend.



The problem then comes with the edges of the tab perpendicular to the axis of the bend, you can't use an extend surface here because of the bend feature. And also ProE sometimes just won't extend edges - It does its usual won't do it, but won't say why either thing.

 

[swcalvert]

Well Jason, I'm in the sheetmetal class right now and I've come across what I believe to be your answer. Create your Flat Wall and then create a Thin Cut (one on each side) and then Create a Bend picking the outside edges of the shape made ny your cut so that you can draw a bend line between them. In this feature (Create Bend) you can tell the system which side of the bend line is the fixed surface and what your radius will be. When I get back to my cube tomorrow, I'll see if I can make one happen.



Steve C

 

[JasonMorgan]

This is the first method I tried, trouble is there is a minimum width to a thin cut - its not infinately thin (actually about 0.13mm) - so adds this error to each edge that is cut, the tab ends up 0.26mm narrower that it would be in real life if the tab was punched out. A considerable error.



I wanted to use a rip (as this is infinately thin), but can't work out how to define it.