Can’t unbend some family members

[michael3130]

hi Everyone,


I've created a sheet metal part with 3 additional family members.


The 3 members vary primarily by length with a couple of additional features as the size grows.


The smallest size undends ok but the 2 larger sizes don't and I can't figure out why. I think it is something to do with the 2 circular flanges, 1 at each end. The thing is the flangesdon't vary across the members but yet only will unbend in the smallest size.


I can't seem to upload the file but I can e-mail it if anyone is willing to take a look at it.


Any help would be appreciated. Thanks in advance.

 

[Asho Pulsar]

To create a family table unbend should be the last feature. If you create an extra feature after that unbend and then again you created a unbend featurewhich you used to create a family table.. it wont work..

 

[sureshdesigns]

pls send me the file


[email protected]

 

[michael3130]

sureshdesigns,


Thanks, I have sent the file to you.


Ashok,


The unbend is the last feature.

 

[sureshdesigns]

Hi all


As per Michael's part experimented by me that throws an error like "Edge chain doesn't split part into two. Can not unbend". pic shown below





The failure occured in the part becos of that circular flange highlighted in the picas pink color. Actually the feature has been created by extruded flange.


As Michael said earlier it works only forfirst smaller instance. For remaining parts with longer length if you try to unbend it throws an error. Wht I did is instead of making extruded flange along the circle Icreated open hem split by half the circle (Semi Circle open hem) then it veifies all the instances successfully.


But I tried to create open hem fully circle using shift key, thenthe last instance of the family with max length failured.


Wht should be the problem when the extruded flange created along the circle?? Whether the circular open hem and the part length is having any realtion??

 

[michael3130]

After Suresh's reply, I split both flanges into 2flange features. Rather than the profile following the entire circle, I set it to go to theend point of the semi-circle. The second feature was again a flange but the profile followed the remaining semi circle.


This then worked and the part unfolded fully but I still don't understand why originally the smallest instance worked but the bigger sizes didn't. The holes are dimensioned to each end. There is no relation between the length and the holes or flanges unless I'm missing something.

 

[conrat]

This could have been a problem with accuracy. I have had to set many of my sheet metal parts to absolute accuracy because when they grow large (some off these parts change length by an extreme amount depending on the configuration) they would fail.

Basically if you have a very small feature on a small part it may work fine. But when the part length increases and the feature remains small, relative accuracy causes problems. This is because the feature accuracy is relative to the overall size of the part. When the part gets larger, the small feature's accuracy decreases and could cause a failure.

Just a thought.
Jim

 

[michael3130]

jim,


I'd thought about that as I've seen posts before about accuracy but never had problems with it before. I'll try adjusting the accuracy and post back here if that works.


Thanks