Hello all,
I have a question, to which I cannot seem to find an answer. I am hoping y'all will be able to help me.
In my work, we use plate steel and bend it. Pretty simple. I use the Sheet Metal application (Creo 3.0, M090), so that I can flat pattern the parts and be able to tell the manufacturing people what the overall length of the part they will laser out needs to be.
I sketch the part in its bent state, and I have been taught/told as best practice (or so I believe). Make some cuts, and I have what I want. I sketch a curve that is half the thickness, and then created a parameter, as well as an analysis feature, and tie said parameter to the measurement. This was, I know what my length SHOULD be. (see my first slide in my attachment) In the first slide, its just a 3D view, and the sketched curve is there to be seen. I have the curve projected to the same height as the points at the ends.
When I put the part on a drawing, I noticed that the dimensions I get by doing the math do not add up. And I have measured what the length should be several different ways. One was via AutoCAD, one with MathCAD. I can get those values to match up. And the measured length from the sketched curve I put in as a feature yields results that are close (but off by 0.009 inch) (and yes, I get it, that's close enough to call it good enough). (see my second slide)
So my questions are:
Why is my flat pattern, point to point measurement, so far off (it's almost 3/16ths different)?
Is this related to the K factor and/or Y factor? If so, how do I manipulate those values, because I have no clue.
Why is the sketched curve off from what I calculate?
Is there a way to get the flat pattern to be true to the length I calculate?
Thank you in advance to anyone who can help me shed some light on this.