Motorized Irrigation Engineering Project

This project was born because I got tired of constantly moving my sprinkler around, so I built this motorized sprinkler system to provide a solution. It’s a 3D-printed timed motorized spool, which pulls a generic water sprinkler to water your lawn without intervention!

Here's a list of all the parts and materials I used. I linked the specific parts I used but there is room for changes/improvements, as I simply went with the parts with the best bang for your buck, so feel free to change parts out to make improvements or to better fit your needs.

18 Gauge Wire

12V Motor Power Supply

Motor controller (2 pack)

12V DC Motor

Sprinkler (Can be any generic sprinkler)

USB Power Bank

Micro USB Cable

Flathead screwdriver

3D Printer

≈250g PLA filament (or equivalent)

Fishing Line

For the base, the purpose is to mount the motor and to gear it down to be slower, higher torque. To accomplish this using the motor linked above, a 10:1 ratio is required. I partially used gears I found on Thingiverse under a creative commons license and adapted them to be as shown above. If you copy the generic design shown in the CAD photos you will be well on your way to completing this project.

Tips:

1. Use 100% infill for all gears and structural components, 30% for all other parts.
2. Depending on the quality of your printer, you may want to use slower settings for all the prints as some of the part tolerances are tight and going too fast could lead to parts not fitting correctly.

Base Assembly

Depending on how you design the base, assembly will look different. But for my design, the 2 gears will simply slide into place and should match perfectly without any further attention needed. We are now ready to work on the electrical and mount the motor onto the gears!

Now that the sled and base assemblies are completed, we are ready to wire everything up and get power to the gears! For this step we will do some light soldering and wire stripping so keep that in mind.

DC Controller

The first step is easy: powering the motor controller! We will provide said power using a micro USB cable connected to either a power bank or an AC wall adapter.

1. Connect the micro USB to the power connection on the DC Controller
2. Next, cut off a roughly 2 foot (size can vary) section of red wire and strip off about a quarter inch from either side. Then use a screwdriver to connect one end to the positive AC 12V power supply connection and the other end to the positive side of the DC controller
3. Cut off a 2 foot section of black wire and strip off the same amount as before. One side will be connected to the negative side of the DC controller, and the other side will be soldered to the motor in the next step

Motor

To wire the motor we will connect the positive terminal to the other end of the black wire from the DC controller, and the negative terminal to the negative connection on the AC power supply

1. Solder the other end of the black wire from the DC Controller to the positive terminal on the DC motor
2. Cut off a 2 foot section of black wire and strip a quarter inch off from both sides, and solder one end to the negative terminal on the motor, and the other end will be connected to the AC power supply and tightened down using a screwdriver

Motor mounting

To mount the motor, the only thing of importance is that your gears align perfectly and all parts are the correct tolerance to fit with the motor.

Attaching to the sprinkler

To attach the driven gear to the sprinkler, grab some fishing line (I used 30lb strength line) and tie one end to the sprinkler and the other to the driven gear through a small hole, an example of which can be shown in the CAD photos above.

And that's it, we're now ready to test everything out!

Hopefully by now everything is connected and ready to be tested!

1. It's a good idea to dry test the motor without any strain to ensure there are no weak points in the electrical connections
2. In a similar vein, ensure the gears all align correctly and interconnect with each other to allow for smooth spinning

Now put it all together, connect the motor to the gears, turn it on and hopefully your lawn now has a motorized sprinkler that waters your lawn with little to no intervention! If you have any questions or help designing the CAD models drop a question below and I'll do my best to answer.