im having some problems with my acme screws being to long and getting some whipping as they turn. what i have now are 10 turn 1/2'' 60'' long for x and y .if i go to 5/8''acme 8 turn for more speed ,it will not have to turn as fast. do i have to change the z as well , and can i program my software to accommade for the difference .i guess ill be using mach 3 as im just cutting foam and 1/2'' mdf. another question is that i have managed to get rid of my backlash on my screws by fitting them perfectly to the end bearing blocks, but will the back and forth motion eventally blow out the bearings, should i be doing something else as well. this is my first build ,and would like to see it run for a while before i need to do repairs on it, do to wear and tear.replies greatly appreciated . ps i wish i was a master at cnc like you pros here .my hat goes off to you. cheers.