# Calculate Torque Required

I am working on a school project that requires me to build a machine. I have designed the machine but I am stuck at torque calculation. The problem goes like this, the machine supposes to rotate a stack of trays (5 trays stacking up vertically) at a constant speed.

Below is the information:

Mass of each tray: 8 kg

Moment of inertia of each tray: 0.333 kg m^2 Let's just say the friction is very small and can be neglected. The rotational speed should reach 1200 rev/min in 5 seconds. How do I calculate the torque required to rotate the stack of trays?

Any help would be appreciated!

• Torque will accelerate the trays until the friction of rotation equals the applied torque. If you don't have any rotational losses, any torque large enough to put the trays in motion will make them move. The data shown goes better with something like "how much torque to get the platter to spin at 10 rev/min within 15 seconds." May 21, 2020 at 1:56
• Let’s assume the friction is very small so it can be neglected and the machine needs to reach 1200 rev/min within 5 seconds. How much torque required to rotate it? Thanks! May 21, 2020 at 2:46

$$T=\alpha I \ = \\(1200 / 60) / 5*2\pi * I = 25.13 *0.333*5=41.85Nm$$