# To calculate torque/power/rpm required

1. Apr 22, 2013

### barrygold

Dear All.

I need to calculate torque/power/rpm required to
lift a 5 kg. load 150 mm. vertically in 10 seconds.

I plan on using a 2mm cable wound round a 20 mm diameter drum connected
to the shaft of a 6 volt dc. gear motor.

Thanks in advance and best regards.

Barrygold.

#### Attached Files:

• ###### Capture.JPG
File size:
14.1 KB
Views:
245
2. Apr 23, 2013

### tygerdawg

You must make some decisions on how you want to move that mass. If you are asking only for torque, then you have infinite possibilities of a solution.

Determine how fast you must move that mass linearly.
Triangular speed profile?
Trapezoidal speed profile?
Harmonic speed profile?

Setting these will determine the force required to move that mass from rest to terminal speed. Be sure to account for gravity effects on the mass in addition to force required to overcome inertia, friction, everything else.

This analysis will provide you witih peak force required to accelerate and move the mass linearly the required distance in the required amount of time.

Torque required is T = F X r (r = pulley radius). De-rate this by motor / gearmotor efficiency, cable slippage, any other loss factors.