[modelman]

edwalsh18-I have not built one of these drives but you really don't need this info. just use a stop-watch and a little imagination. Take the distance(in inches) you want the ram to travel. Say maybe you need 3" travel. Time an object by moving it 3" at the speed you want your rams to move. Then just do the math. Decide what thread type you want to use(tpi) and that tells you how many revolutions it take to move the required distance. That will give you an RPM you need in the correct amount of secs. Then get a gearmotor with that RPM and you will have what you want. Hope this makes sense-ask questions if you like. There are lot's of people on here that can help.