1. 1 SPIRIT Silicon Prairie Initiative on Robotics in Information Technology DC Motor Parameters

2. 2 SPIRIT

3. 3 Mark max Torque Y Axis Mark Max RPM X Axis X X Connect the points with a straight line

4. 4 SPIRIT X X Locate the Mid Point RPM Trace a horizontal line to the Y Axis This is the Design Torque Value X Mid Point RPM

5. 5 SPIRIT ALWAYS Record, Describe and Date the Data

6. 6 SPIRIT Measuring Armature Coil Resistance The Multi-Meter selector is set to read resistance in units called ohms (  ). The selector is set to the lowest range (0-200  ) The Value measure is 0.9 ohms.

7. 7 SPIRIT Measuring Armature Coil Resistance Set the meter to read ohms. Use the lowest range. Short the meter leads and record the value. This is the meter error value. Attach your meter to the two motor leads. Slowly turn the armature shaft and record values at 45° intervals. Average these values. Caution: Turning the armature shaft quickly, induces a current in the armature windings. This Will damage the meter.

8. 8 SPIRIT Calculate the Stall Current I = E R Ohm’s Law The basic Algebra of electronics E = Voltage I = Current in Amperes R = Resistance in Ohms, 

9. 9 SPIRIT Determining the Torque Value ALWAYS Record, Describe and Date the Data D F F = Force (lbs.) 3 lbs D = Length (ft.).5 ft Q = Torque (ft.lbs.) Q =D x F 1.5 ft.lbs. =.5 ft. x 3 lbs.

10. 10 SPIRIT Evaluating DC Motors Determining Robot Speed

11. 11 SPIRIT ALWAYS Record, Describe and Date the Data Robot Speed Equations Use this equation to predict the TekBot’s speed

12. 12 SPIRIT