Suppose you have 3" tube acting as a post. A piece of metal is inserted into the pipe. The part inserted is 2 1/2" and the outside part 18". Your need to lift a 70 lb. platform resting on the external part of the piece of metal. If a spring is placed under the inside end of the piece it would pull down on the short end that is only 2 1/2" and needs to lift 70 lbs. You may add an additional spring to help pulling down on the short end or place a spring-out device (sping that pushes out or shock absorber pushig out) pushing up on the outside of the metal piece. As a result you would have a spring pulling down on the short end and a spring pushing up just a few inches from the pivot point. What would be better, using 2 springs on the inside end or a spring on the inside end pulling down and another on the immediate outside pushing up? Is there a formula to determine this?