My boss is an old school guy and still uses coils so he is not any help with this. I started using rotary machines about a year ago.Anyways I am about to make the jump from a standard set up on my direct drives to stainless grips and carts. I currently run a spektra direkt 4mm and a hm dd 3.5mm. What I was wondering is do I bother running a rubber band on my plunger bar? I don't see how this would matter seeing side to side wobble of the plunger bar shouldn't effect the motion of the cart. One of the main reason I feel switching would be a good idea for a dd. Plus I don't want to put more stress on the motors then needed. Someone correct my if my logic is wrong.