Accounting For Material Thickness

Hi there, I'm new to the forum and I hope some of you fabricators can help me out!
I'm trying to figure out how to factor in material thickness to my flat patterns.

Say I lay out a cone on a 1/4" plate - 12"dia to 10"dia and height at 6".
When I roll that cone, will the dimensions I used end up being the mean diameter? (in the middle of inside and outside diameter) or would my dimensions end up being the inside diameter?

For instance, if I wanted a 24" ID cylinder out of 1/4" plate I would cut my blank (24+0.25)(pi)=width
and if I wanted it 24"OD I would cut my blank (24-0.25)(pi)=width. Simply just adding and subtracting material thickness.


I just got this flat pattern unfolding software (Sheet Lightning Pro) and it has all of these cool 3d profiles like offset cones and square-to-round transitions where you just type in a few dimensions for the variables, but I can't find any inputs for material thickness. Just trying to avoid wasting a bunch of good material trying to figure it out.

If anybody has some advice I would really appreciate it. Thank you!

 

I don't have the answer but I'm really interested to see how you roll 1/4" plate into a cone. Post pics!

 

*Truncated cone, if that makes any more sense. Basically, we have a motorized roll machine with (3) 9" diameter x 74" rolls. I'll get some pics next time I get a chance.

 

Try Plate N Sheet software its simple to use and takes care of plate thickness. But you will indicate if your diameters are outside, inside or middle