Sheet metal Flat Layout Ellipses

[johnnymcmaster1833]

Hey,

I have an issue with flat layouts, when a draw a round object such as a rolled punched plate it would be nice to have the flat layout show what the hole callout and spacing would be, however with the way i draw the model. the holes come out as an ellipse, attached is a document showing how i drew the model. Any help is appreciated, Thanks.

[JDMather]

You have modeled the part incorrectly.

If you manufactured it the same way you modeled it - the results would be the same as what you posted.

I'll be back in a minute with a correct solution.

[mcgyvr]

What are you expecting the flat pattern to look like?

Obviously a perfectly round circle punched in the flat pattern is not going to be a circle after roll forming and a circle drilled though when formed is not going to be a circle anymore after unfolded..

[JDMather · Accepted solution]

Here is one method.

As noted - cannot be round in both the flat pattern and the folded.

You will need to determine which condition is most important to you - then best solution can be proposed.

[johnnymcmaster1833]

Ok will check out your models, as i stated in my original post i want the holes to be in the flat, since that is how they will be manufactured, i am not able to draw on the model in the flat layout (at least it wont save it), i will look at your models to see if you came up to an awnser to my question, thanks.

[JDMather]

I will have to post one additional technique.

[graemev]

"... with the way i draw the model. the holes come out as an ellipse..."

That's because the way you modelled it, the holes ARE an ellipse when the sheet is flattened.  Perhaps you wanted to punch a flat sheet with a round punch and then roll (bend) it?  Alternately, make a leader text note?

[johnnymcmaster1833 · Accepted solution]

I tried your models and it worked well. I also do alot of cylinders out of punched plate, and after playing around with the unfold and refold commands, it seemed like that worked best for my needs so you can draw the shapes/patterns you want in the flat.