Sheet metal hole knock-outs

[cowman]

Hello all,

I am looking for some ideas on how to represent hole knock-outs (holes not cut all the way around) on sheet metal flat patterns. We use the flat pattern to create DXF files which are used as input to our lazer cutters so we need the knock-outs to be saved on the flat pattern.
Thanks.

 

[CorBlimeyLimey]

Laser cut (with connecting tabs) or partially punched (like electrical box)?


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[cowman]

Laser cut - with connecting tabs

 

[Trogdor0]

If you create a knock-out like it would be made, with the connecting tabs, then it will show up in the dxf of the flat-pattern.

 

[ctopher]

I think I have seen knock-outs online that can be downloaded. Do a search.

Chris
Sr. Mechanical Designer, CAD
SolidWorks 05 SP1.1 / PDMWorks 05
ctopher's home site

 

[MadMango]

I've created Forming Tools for these in the past (last company) just for representation. If you do sheet metal in-house you can go the laser-cut route. If these parts are going out to vendors, you really don't want to define the manufacturing process, unless laser cutting is a quality requirement of the part.

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[CorBlimeyLimey]

cowman ... Are you using the Sheet Metal module? If you are, then, as Trogdor0 stated, the semi-circular slits which create the knock-out feature, will automatically be included in the flat pattern & DXF files.




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[cowman]

The way we made a knock-out in our old cad package was to create two single lines ("C" shaped)with a gap between them. The laser would then make a single pass over these lines creating the knock-out. I assume when you say to just create the knock-out I will need to offset the "C" shape a small distance and make a closed shape for the knock-out.

 

[CorBlimeyLimey]

Just make semi-circular slots (the width of the laser). Three slots might be better, so that the "slug" does not twist & catch up on other parts.

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[aamoroso]

You should create a couple of basic Pallet Features for this. We created small single tab knockouts that we use for .437 - .625 knockouts, two tab knockouts for .625-1.00 and a four tab for knocouts over 1". Then we just click Tools - Feature Pallet and add the appropriate type of knocout and adjust the diameter.