What size motor do i need?
What size motor do i need?
(OP)
Hi, i have to spec a motor, what i need to know is how do i figure out there torque required? it is a vertical shaft, bearing a load of 4kg, load diamter is 100mm. motor run time per cycle is 30 sec, so it needs to start quick, and stop quick. Im limted to a 750W input supply. length of shaft approx 100mm. any help would be great





RE: What size motor do i need?
The gravity weight of 4kg acts at a torque radius of 100mm, correct?
During this 30 seconds, do you expect roughly constant speed or roughly constant acceleration or something else? If constant speed, how long to reach the target speed? How long the total distance travelled in 30 seconds?
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(2B)+(2B)' ?
RE: What size motor do i need?
RE: What size motor do i need?
You need to consider acceleration time for the motor to drive load at required velocity.
RE: What size motor do i need?
How often does the cycle repeat?
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(2B)+(2B)' ?
RE: What size motor do i need?
Mass = 4kg
Weight = Mass*g = 39.2N
R = 0.1M
Torque = Weight*R = 3.92 N-m
Power = 2*Pi*Torque*Speed = 24.6 watts (using speed = 60rpm).
That is the just the power required to keep the weight moving at a constant speed (the easy part). Need to think about how much additional torque you need available to get proper acceleration as mentioned and consider duty cycle and other factors to come up with good solution. I'm not the right guy to select this motor.
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(2B)+(2B)' ?
RE: What size motor do i need?