Trim/Extend Model

[Coolboy55]

Suppose there was a model that looks like a sharpened pencil with an eraser on the other end. How could the cylindrical pencil body be shortened while specifying which end moves in? I have tried to set locked dimensions but haven't had any luck yet. Is it possible to create an anchor point of some kind that doesn't move from that absolute position in space?

Thanks!

 

[Coolboy55]

Sorry, I think I was unclear. The problem isn't in setting the driving side of the dimension but in correctly pulling the features beyond the dimension inwards without stretching or distorting them.

I also tried to cut a section out of the pencil and move the ends together, but I can't figure out how to join the two parts together either. Sigh...

 

[bmlkidd]

Without seeing the model, it's hard to say exactly. But lets say you had the cylinder tied to a reference plane, then when you alter the extrusion length, it should act like a pencil being sharpened with the point cutting down toward the place.