Quote Originally Posted by Rogue View Post
The stepper & ratio issue is something I've yet to address. I need to work out the benefits of the various ratios first. I'm pencilling in 1:1 until I've had a good think over a hot cuppa.
If you haven't bought the screws yet then I'd go with 1/1 and get the correct pitch screws best suited to your needs. Mainly for simplicity.
2/1 will double the torque but half the speed and so on. 1/2 will double the speed but half the torque and so on.
One of my machines use's 1/2 with a 20mm x 5mm pitch screw which effectivly gives me a 10mm pitch screw but with reduced torque, the plus side being it's a simple belt & pulley change and I have full torque and high resolution but at half the speed, It works good.
2/1 is usefull if you have small Nm steppers which tend me able to spin faster than larger steppers but with lower torque couple these with a high lead screw and smaller steppers can be made quite strong.