I'm designing a waterwheel powered rock tumbler and this is exactly what i needed. How big do I have to make the wheel to turn the barrels? This video helped a lot!!!
So does this mean I can use teeth on the the pulley for that math. Like a stepper motor with 20 teeth driving a pulley with 80 teeth on a g2 timing belt would be 20/80? How does torque effect it? Does the length of the belt or the distance from the center of the pulleys make any difference?
Good questions! Teeth, radius, diameter, circumference can all be used to calculate velocity ratio. In your example it would be VR = driven / driver = 80 / 20 = 4 The motor would rotate 4 times for every 1 rotation of the output pulley. The ratio is not affected by torque or distance between centres.
@@PizzeyTechnology Thank you very much. I'm building a scara robot. I found a turntable at home depot for $4 bearings are expensive. I also found out that 5/16 rods are close enough to 8mm to work. I'm using a threaded rod instead of a lead screw. I got 4 stepper motors for Christmas.
if you need to calculate a driver/motor wheel size to drive a driven wheel at a specific rpm ...divide motor rpm by the needed driven-wheel rpm=velocity ratio ...then divide the driven wheel size by the velocity ratio=needed driver wheel size. .............(an example for a needed 900rpm driven wheel speed with a driven wheel size of 250mm and a 3650rpm motor speed) motor 3650rpm/900rpm=4.05 driven wheel size 250mm/4.05= 62mm driver wheel size needed for 900rpm driven wheel speed.
