Bend relief - big holes!!

[sijcooke]

Hi All,

Can someone help with the attached inventor part. I sometimes corners come together nice and tight, and sometimes they have a huge bend relief gap as shown.. what ever i do i can not close it up!

Thanks,

Simon

kelly.young has embedded your image for clarity.

[Fouad-l]

Hi.

I think you should adjust bend radius value according to sheet metal thickness.

See below the minimum bend radius for each material thickness

http://www.americanmachinetools.com/bend_radius.htm

[jeremy_wasserstrass]

Did you use the corner tab in the Flange tool(the same tab is also in the Corner Seam tool)? The choices on that tab will let you adjust your corner type, though with the type of corner you show the relief is set by the bend radius.

[johnsonshiue]

Hi Like Latrach and Jeremy mentioned here, Bend Radius to Flange2 is too big so there is a big relief. Change it to a smaller value and you will see the gap becomes smaller. If you want to change the shape of the relief, it will have to be done in "sides" -> Corners -> 3-Bend Corner. There you can control the relief shape on the flat pattern body.

Many thanks!

[sijcooke]

Hi all,

I have had a look, and i dont understand. When i edit the flange the graphics show the corner closed up nice and tight. When you close the flange setting dialog box a huge bend relief appears again.

I cant see why bend radius has anything to do with it.. i tried putting the radius down to 1mm and still the same problem.

I have attached another part.. exactly the same material, radius etc, the flange is set the same with the same TEAR bend relief, gap size 0.1mm.. and it works fine on this part??

Thanks,

Simon

[jeremy_wasserstrass]

The bend radius is what determines the amount of relief needed for the bending to take place. Based on experience your relief needs to be big enough that you are not trying to compress any of your material, it leads to ugly corners when tried. This is why we use arc weld or linear weld for our corner reliefs where I work.

[sijcooke]

Hi,

Thanks for the reply.

If you look at the two attached items above, they are exactly the same material, same relief etc... but Part1 has worked fine, and the other part (RES bracket) will not close up on the corner?

It keeps putting an excessive corner relief on!

In the attached image, it closes up the corner when you edit the flange.. but as soon as you click ok or cancel, the hole re-appears!

Any more help would be great.

Thanks,

Simon

Alco

kelly.young has embedded your image for clarity.

[jeremy_wasserstrass]

I don't know why the display does not preview the type of relief chosen on the model while the tab to make changes is open. Maybe @johnsonshiue can explain why, though I think it has to do with the little picture in the corner of the corner tab showing what profile each type of relief will generate. The thing is you need to choose what you want for a relief as the default for Inventor is the square relief(trim to bend).

kelly.young has embedded your image for clarity.

[johnsonshiue]

Hi Guys,

The two parts are actually different. Part1.ipt has a two-bend corner. Basically the two bends and their flanges meet somewhere. Res bracket.ipt has a three-bend corner, where three mutually perpendicular bends meet. When I said bend radius mattered, it was about the vertical bend. The vertical bend creates a natural gap that the relieves cannot fill. The preview shows nice bend transition shape but it was kind of cosmetic. It is not fully computed geometry. Try this. Go to Res bracket.ipt. Edit Flange2 and change Bend Radius to 0.1 or something. You will see the transition shape looks closer to Part1.ipt.

Does it make more sense now?

Many thanks!

[sijcooke]

Hi,

Yes this makes sense. 

Thanks for your help.

Sijcooke