machine made rams

[maddox10]

what mathamatics would have to use to know how work out the bore, bar & stoke of the home made ram?
for example FESTO DNC-50-40-PPV-A STK 40MM BORE 50MM 10BAR PNEUMATIC CYLINDER B374069' that I found on ebay.

Strange question. You design a ram to do what you want.
Bore and stroke are mandated by the force you want to produce, and the space you have.
But basic mathematics. Force is the result of pressure on a surface.
The surface of a normal ram is a circle. Surface of a circle is radium*radius*pi (radius is half the diameter or bore)
Bar is the unit for pressure in kilo per cm². 1 bar means 1 kg of force on 1cm².


For that tiny festo ram you found on Ebay the following numbercrunching will happen.

40mm bore. In cm you get 2cm*2cm*pi=12.56 cm² @ 10 bar that makes 125.6 kg of force over 50mm.