Hi Burr,

> Just so I'm clear. I'm not sure which number is the "actual" size.
> So if I were to create a 1 inch square to machine, Would it be the
> new "size" option or the "custom distance tool".
>
> I guess I just dont understand when this number can be different
> and why.

The size that is reported is the size of the object's bounding box in the world coordinate system (unless you set a custom cplane in which case it is in the cplane coordinate system - setting a custom cplane basically re-orients the grid to a different position and rotation).

But a bounding box around an object can have different sizes depending on the orientation of the object.

Here's an illustration - here I've got a 5 x 5 square, which is aligned with the x and y axes. The x and y axis bounding box around this is the same exact size as the square itself, and you can see that the size readout says 5 x 5:



Now let's say we take that square and rotate it, the bounding information will change, even though we did not scale the square:



That's because a rotated square has a larger bounding box than the axis-aligned square, here I've drawn the bounding box to illustrate:




The sides of that original 5x5 square are still the exact same length as before, but the bounds of it are different.

Which one is most important to you (the length of the square's edge versus its bounding size) may be different for different kinds of purposes, but I would think that when you were machining you would probably consider your stock to be a world aligned piece and you'd be interested in the overall size of the object in that stock rather than the size of the rotated edge? If so then the current size readout should be the right thing for that.

Actually that would help me to know what you expect to see when the 5x5 square rotates - would you always want to see the size as 5x5? Or would you like to see the bounding size which changes as the object has different rotations?

- Michael


EDIT:

Just to try and clarify further, this is where the size is coming from with the rotated square: