Sheet Metal Rounds and Deformations - It Should Work

[merrill.rosenow]

Good afternoon everyone,

I am working on a sheet metal part that is essentially a5" by 6" rectangle with 1" flanges on each of the edges all oriented in the same direction. We will be getting a tool to blank the flat pattern of this part. As such, the tool will be cut with a wireEDM and requires rounds on all of the corners at least as large as the wire.

I created the formed part, flattened it out and added rounds toall of the corners. I then made the rounds a deformable area so that there would be no issues bending the part back. Or so I thought. The rounds on the outside edges were okay, as they do not directly affect the formation of the part. However, the four inner corners with rounds caused the part to fail.

Is there a trick that I can use to get around this? (Pun not intended) Increasing the spacing between the formed edges of the flanges to give room for the round is likely not an option.

Thanks in advance!

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[BrentDrysdale]

Hi Merrill,
I think from your description that the fillet you added has made an
unrelieved area for your side folds which means ProE will not re-bend it.

Basically you need to create a relief somehow. There are relief options in
the folded wall commands but you may prefer to add the relief to the flat as
that was where you added the fillets. Common relief methods are to use a V
notch or a partial circle which sort of makes the corner look like the Earth
symbol from Stargate.

Regards, Brent Drysdale
Senior Mechanical Designer
Tait Radio Communications
New Zealand
DDI +64 3 358 1093
www.taitradio.com

[merrill.rosenow]

There is a way to do this, however I have been trying to avoid it since it is a work around by every definition.

The part must be created as a solid, however only the basic shape with the details that cannot be rounded need to be created. Each area where there are rounds created as a portion of a hollowed out sphere with the same thicknesses as the rest of the part. Creating the proper shape and using the shell feature is the easiest and most robust method of doing this. The part must then be converted to sheet metal adding all of the remaining features required. The reason you do as little in solid mode as possible is to avoid bending/unbending issues down the road. The more you can do in sheet metal the better.

Creating the part using this method forces the spherical areas to be proper deformation areas. They can then be notched to give the proper geometry.

The sad truth is that this requires the part to be completely rebuilt from the bottom up, and initially as a solid at that. I'd like to do this the "proper" way however the excellent suggestion of using the relief features will not give me the desired geometry to reflect the real life model

I will reward anyone that can come up with another solution with a virtual high-five. Let the challenge begin!