Kayla Peters and Alec Freeman
The Center Pivot Irrigation Demonstration was designed with hopes of reaching farmers and classrooms. This project covers information about 3D printing, design, and agricultural technology. If you are interested in collaboration with CU-CAT, teachers, and others in the agricultural community you can do so through Github. You can provide input about adjustments to the design, ideas for lesson plans, and even collaboration about 3D design. We encourage those that are eager to take this opportunity to explore the different aspects that are incorporated within this demonstration.
How Our Center Pivot Model Operates
The Center Pivot Model is powered using a power supply (power converter) to convert 120v AC to 5v DC power. The system is powered on with an on/off switch. When switched on, the power supply turns on a pulse width modulation controller (PWM). The PWM pulses the power in microseconds to control the speed of the system. The controller also is adjustable to increase or decrease the duty cycle so the pivot will run faster or slower. The knob on the PWM must be pushed in once to start the system. The end tower is the driving tower. As it moves, the intermediate towers will follow. The speed of the intermediate towers are also powered by the PWM. The intermediate tower motors are initiated when the limit switch on the tower is activated. Once the limit switch is closed, the tower will move until the section is in line with the rest of the pivot. Each intermediate tower moves individually and continues until the end tower is deactivated.
The TT motors run directly into a worm gearbox which rotates the wheels. This slows down the speed of the wheels using a 9:1 ratio of the gears. The motor rotates 9 times faster than the wheels due to the interference of the gearboxes.
The direction of the pivot rotation is controlled by swapping the polarity of the system. By using 2 single pole double throw relays or one double pole double throw relay, the polarity of the system can be swapped by simply powering the relays with 5v. This is initiated by using a simple switch. This technique is possible because the circuit is controlled by a direct current (DC) power source.
The system can be deactivated in multiple ways. If the stop switches on the end tower are closed, then the end tower will stop. Once the end tower has stopped, the intermediate towers will keep aligning until their limit switches are back open. Another way to stop the system is by simply turning off the main power switch or by pressing the knob on the PWM.
Materials Needed to Create a Center Pivot Based on Our Design
Materials Required for Creation:
- Speed Regulator – 1 of: EC Buying 2Pcs ZK-MG PWM Motor Driver DC 5V 12V 24V Motor Speed Controller Adjustable Speed Regulator Digital Encoder Duty Cycle Frequency Housing with Stepless Variable Rotary Switch Signal Generator
- PLA Filament – 1 of: OVERTURE PLA Filament 1.75mm PLA 3D Printer Filament, 2kg Cardboard Spool (4.4lbs), Dimensional Accuracy +/- 0.02mm, Fit Most FDM Printer (Space Gray 2-Pack)
- Shaft Motor – 1 of: AEDIKO 8pcs TT Motor Dual DC 3-6V Gearbox Motor 200RPM Ratio 1:48 Shaft Motor with 2.54mm Wire for Arduino DIY Smart Car Robot
- Wheels – 1 of: ThtRht 8 Pack TT Motor Wheels Replacement Smart Car Robot Wheel Tyres 1:48 Model Gear Spare Parts for Gearbox RC Chasis Arduino DIY Kit Remote Control Cars Rubber Tire
- Phillips Head Screw – 1 of: Small Parts Steel Pan Head Machine Screw, Black Oxide Finish, Meets ASME B18.6.3, #1 Phillips Drive, #4-40 Thread Size, 1-1/4″ Length, Fully Threaded, Import (Pack of 100)
- Micro Limit Switch – 1 of: BlueStars Pack of 10 V-153-1C25 Micro Limit Switch Blade Momentary 250VAC/125VDC 15A perfect for Arduino, Appliance and General Electrical Equipment Supplies
- Channel Relay Board – 1 of: AEDIKO 4pcs DC 5V Relay Module 2 Channel Relay Board with Optocoupler Support High or Low Level Trigger
- Connector Kit – 1 of: Twidec/500PCS 2.54mm JST Connector Kit with 2/3/4/5/6 Male and Female Pin Housing Connector Adapter Plug and 2.54mm Female Pin Header Wire Terminal Connector Kit N-010-W
- Power Supply Adapter – 1 of: 5V 10A Power Supply 100-240V AC to DC 50W Power Adapter 10A 9A 8A 6A Converter Transformer 5.5×2.5mm Plug for Christmas Lights, WS2811 WS2812B USB-HUB LED Strips Light
- Wiring – 3 strand 22 gauge
- Pliers – Taking off the brim and bracing off of parts
- File or Metal Ruler – Shaping your pieces after removing the brim for presentation purposes
- Screw driver – Philips head, maybe a flat to take pieces off the printer
- 3D printer – Sovol 3D Printer, model svo4
- Waterproof Plastic Electrical Box
- Nuts – m4-40
- Waterproof Plastic Electrical Box
- Quick Connects
Can be Used but NOT Required:
- Drill Press or Drill
- Solder
- Soldering Wire
- Heat Shrink
- Heat Gun
- Sand Paper
- Solid Works
