LAST EDITED ON Dec-14-04 AT 07:38AM (MST)[p]Making your arrow shorter will make it stiffer. Longer will make it weaker. It all depends on your bow weight, point weight, draw length and the spine of your arrow.
With my compound I cut my shaft to be about 1 inch to 1 1/2 inch from my arrow rest. I have enough adjustment with the adjustable poundage, the arrow rest, ect that as long as I am using an arrow that is close in spine for my set up I don't worry too much about using arrow length to adjust flight.
With my Recurve I don't have the adjustments of poundage and rest (I shot off the shelf) so arrow length becomes a lot more important to get good arrow flight. I will start off with a long "weak" arrow and cut off a 1/2inch at a time until I get good arrow flight (bare shaft tuning). If I get too short then I need to pick an arrow with a different (stiffer) spine and start over again.
If your compound set up is shooting fine now I wouldn't worry about your arrow length. If you are having flight problems then I would play around with weight seting, rest adjustment ect.. before you start playng with arrow length. Also make sure you are using the right spined arrow for your set up.
Mark