The default k factor is 0 44 which simply means that inventor is assuming that 44 through the cross section of the part the material is not stretched or squashed when bending and therefore this slice of the folded part will give the true length of the flat pattern.
Inventor sheet metal k factor.
Michael davis owner of ycg inc.
By default inventor uses a k factor for calculating bend allowances.
Using ilogic to access the inventor api we created a custom iproperty and pushed the k factor from the current sheet metal style through to it.
Sheet metal k factor.
For our example it comes to.
The ilogic rule code is shown below.
Products and versions covered.
We produce a lot of sheet metal work using invento and use 0 2732 for below 3mm sheet and 0 3365 for 3mm and above using ilogic we automatically set the k factor depending on the thk of material so we don t forget to adjust it each time.
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The k factors mentioned are to suit our own press and tools of course.
So for a very large radius bend where the neutral axis lies right in the center of the material the k factor would be exactly 0 5 or half the thickness.
This is not as easy as pulling a parameter through to the drawing as the k factor value is embedded in the sheet metal style of the component.
Plug the bend allowance ba the bend angle b inside radius ir and material thickness mt into the below equation to determine the k factor k.
Most cad systems that have sheet metal design tools will allow you to input a k factor that the software uses to calculate the unfolding to give an accurate blank or flat pattern.