A manufacturer of collegiate basketball hoops was looking to develop a motorized backboard that could raise and lower to position in 25 seconds. The scissors-like action of the lift mechanism, and the load resting on the end of the articulated arm, created the challenge of varied torque (up to 700 in-lbs) at different points throughout the operation cycle. This, along with requirements for the motor to operate on a standard 110 VAC, 20 amp circuit, limited motor options.
After extensive calculations and testing, a permanent magnet DC (PMDC) motor with a speed of 4250 RPM, and a high-torque right angle gearbox with a 30:1 output ratio was selected. Using 115 VAC with a transformer boost to 230 VAC and a rectifier produced 180 volts DC and enough torque to lift the hoop and shot-clock smoothly and quietly within time limit. Testing included a five year life test (2000 cycles) and current draw tests, to rule out circuit overload.
- Varying high torque requirement (due to pivoting boom) up to 702 in-lbs
- 25 second time-frame to raise and lower the backboard to ten feet
- Power supply of 110 VAC on a 20 amp circuit
- 180V DC gear motor with transformer and rectifier to convert from 110 VAC power
- High torque right angle reducer (30:1) coupled to a massive 1.5” diameter lead screw
- Life tested to 2000 cycles, or 5 years