Joe2000che brought up a valid ? in my build log concerning me using all threaded rod for the lead screws versus Acme.
http://www.cnczone.com/forums/showthread.php?t=34839
My initial thinking was that the lead screw
1. the all thread would wear out the Delrin before its self.
From what Joes said the acme will wear first... so my thinking was flawed.
2. i thought since the TPI on the all threaded rod would give more torque, since it has a higher thread count than the acme (1/2-13 versus 1/2-10)
Again my thinking was wrong, Due to the fact that the motors would be spinning faster which would put them out of their torque range.
3. i did not think at the time about whip on the X axis since i am running 4'.
and the acme is stonger versus the all threaded.
4. I was just using the standard plans and di not think about upgrading at the time..

SO, after geting all that straight i plan on using the zylotex motors with their kits. i planned on the 425oz motors which are 10.00 each more added to their kits.
What is the proper way to calculate the turns per inch
i first figured 1/2-10 acme but then it was recommended to go to 2 start which would be 5 turns per thread.
I assume that you would use the normal cutting speed of the router( for cutting wood or plastic what speed is that?) and then use the peak torque of the motor to get them to match correct?
Appreciate any help and Joe has been a great help also..Thakns Joe.
Also i do realized the cost aspect of using the all thread and the standard 1/2-10 acme then steping up to a 2 turn will cost 5 times more but i will evaluate this point and i see mcmaster has 5 different turn per inch 1/2 acme so im just trying to decide whats optimum and what it will cost me.
Thakns for any help Chris