Stir motors are devices which contain a large magnet under a heavy, chemical resistent flat surface. The magnet is spun by an electrical motor. The organic chemistry teaching labs have several different styles of stir motors, two of which are shown in the photo below. Each has a knob on the front which controls how fast the magnet spins.

Although they look durable, stir motors can be damaged if miss-treated. If they are dropped, especially on their side, the shaft which controls the magnet can become bent, and the stir motor no longer spins. They must protected from water, since this would ruin the electrical circuitry. The cords are susceptible to damage: do not drop chemicals on the cords, and keep them from hot surfaces. Always unplug the units by placing your hand directly on the plug and pulling firmly, do not grab the cord and yank it from the socket.

Always return the stir motor to its storage location in the lab room when you are finished with it. Please, wrap the cord around it snugly, too.

The stir motor on the right, the round one, is especially susceptible to damage if dropped on its side. It also actually has two parts, the motor and a plate on top of it:

If it does not have the plate on top, the spin bar spins out of control.

Stir motors are used to cause stirring in a solution. This is accomplished by putting a spin bar into a flask containing a liquid:

		drop the spin bar into a flask containing a solution . . .
			. . . this is how it looks with a spin bar in the flask

Location:

• rooms 27, 73: in the cabinets in the balance room
• room 25: in the large grey metal cabinet by the main hood
• room 72: on the lower back shelves

Cost: $125.00. These are community equipment, and therefore you are not charged if you break one. But, be aware of the replacement cost and handle them with care.