Hi, this is my first posting on this forum in the hope someone could assist me with a calculation. I have read several threads which I think partly covers my problem but to be honest the example answers given are way beyond my comprehension. Basically I need to raise a platform which runs on two vertical tracks by the use of stainless steel wire rope which runs over and around a series of sheaves to a hydraulic ram. Space dictates the maximum ram stroke I can accomodate is 600mm and I need a vertical lift of 2m. The total load including the platform is 430Kg so I have come up with a workable solution based upon an earlier unit I built. Although this only had one sheave so the calculation was within my scope with a bit of guesswork for resistance. I have tried to find out the resistance of the pulley sheaves which are 75mm dia. from the supplier, but they are rather vague and suggest I allow between 5 - 10% on top? However, reading some earlier threads I have seen one reference for plain bearing sheaves, K = 1.09. I am attaching a diagram which I hope explains the principal of this design, if anyone is able to assist in plain English what push the ram (in Kg) is needed it would be extremely helpful. Many thanks in advance.