Sheet metal Cut Weirdness

[dgschaefer]

WF4, M080



OK, sometimes sheet metal drives me batty.  I have two near identical
parts, in fact one is a copy of the other, but tweaked to end up as a
mirror image.  On one part I've added a cut to a corner of a hemmed wall
and got exactly what I wanted:







On the other part, the same cut built the same way gets me this:







It's trimming back and distorting the bend on the hem.  The first one
will flatten as expected, the second won't.  I've tried alternate sketch
planes, closed vs. open sketches and different dimensioning schemes and
nothing changes.



Can someone tell me why this is happening?



Doug Schaefer

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[DeanLong]

Doug,

What does a section perpendicular to the bend look like? Is it a closed section? If not, then it's a geometry issue requiring further investigation. The unbend fail hints at a geometry issue, but check it nevertheless.

You said it is a copy of an original part and then mirrored? You could be running into a accuracy issue related to the bend table. Is the part file you copied things to the same?I.E. units, accuracy? Is the bounding box of the failingpart the same as the first?This will impact the success rateof wacky features like that.

Other than that, it looks like a simple part. Maybe model the oppostite part from scratch and see if get the same failure?

[merrill.rosenow]

If you are trying to make an identical mirror, I strongly suggest you use the File>Mirror Part command. Make the first part exactly how you like it for that hand, then mirror the entire thing. Besides the benefits of avoiding issues such as these, if you need to make a revision you only need to modify one model tree and not two.

Without seeing the feature itself it is hard to say what is happening. I have had some very bizarre graphic issues when trying to modify the corner of a rounded deformed feature.

As for the accuracy, the absolute or relative accuracy has not given me troubles with features like this. When I do have a problem, the feature fails "for no reason." I change the accuracy to the smallest allowable absolute accuracy and have always been okay.

[DaleHvizdo]

Is there a way to make the repeat region filter out tools not used in a nc
operation? Or is there a parameter to use instead of:
&mfg.oper.workcell.head.tooltbl.tool_pocket.tool_position. We only use
several tools for the OP020. I would like to let operator know what tool's
are only used in the operation.



toottable1.jpg



Thanks

Dale

[PaulMailloux]

Hey Dale

We use these values.... Below is a sample.

&mfg.oper.ncseq.tool_id

&mfg.oper.ncseq.pocket_number







Paul Mailloux

Cad/Cam Applications Engineer

NyproMold Inc

144 Pleasant Street

Clinton MA 01510