Join Date: Dec 2004
You're right, but as I recall, the time of the pendulum works in part on the distance to the center of the pendulum's mass, not just its total length.
With a weight that slides for a long distance down the blade, you're right. The blade gets progressively more tip heavy, meaning that it will take more energy to move the tip and that it will hit harder (transferring more energy).
If the slide is short, around the blade's normal center of mass, what would happen is that the sword would go from back-weighted to front-weighted. Basically, this would mean that the sword accelerated a bit faster from rest (starting out back-weighted, as in a small sword), hit a bit harder (shifting to front-weighted), and was a bit harder to withdraw (still front-weighted). This type of design makes a lot of sense when you're only planning a single blow, as in an executioner's sword. In a battle, I'm not so sure that it's advantageous, but I don't know. We'll have to see what the engineers say.
One thing to remember is that a blade with a slot down the middle is probably more fragile than a solid blade of the same weight. Jens has proposed an interesting question, and it will be interesting to see some numbers around it.