New seeder tool design from Liberty University

Greetings FarmBot Nation!

I am excited to show you the latest prototype seeder tool for the FarmBot designed by Liberty University. The intent of this tool is to allow users to drop pelleted (spherical) seeds directly onto specified locations in the soil.


The design is based on the classic seed drill design (Jethro Tull c1701) with a slightly more modern flare.

Specific Design Details:

Capacity: The seed hopper will contain between 50 and 100 seeds.
Utility: The turnstyles will be interchangeable so you can can work with different seed sizes.
Accuracy: The seed will be dropped within 5mm of the desired target.
Servo: SunFounder SG90 Micro Digital Servo Motor SF0180 for RC Helicopter Airplane Boat Robot Controls 9G

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Operation of the tool:
A seeding spike will be used to create an indentation in the soil before this seeder tool will drop the seed into the soil. The watering tool will shower a bit of water on the soil and then it will create the perfect conditions for germination.

Servo control will control the turnstyle to allow only one seed to drop at a time.

The design is similar to other seed drill designs like this one from Europe:

Over the next several months the Liberty University design team will work with this prototype and develop it into a working seeder tool.

If the seeder tool is successful FarmBot Inc. may consider including it in the tool offering. The design along with more information about the seeder tool will be released in the coming months.



Very Cool to see such ingenuity!
And… i never knew the story about Jethro Tull!

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That was a cool little history lesson. Really awesome idea!

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I love the design, how is the hopper filled with seeds? And how is the turnstile changed to accommodate larger and smaller seed types?

@Sjamesparsons The top will twist off similar to a pill bottle. You will add the seeds in the hopper and then put the top back on.

The turnstiles are changed out by loosening set screws and sliding off the turnstiles from the main axel. We expect to be able to accommodate 3 or 4 seed sizes.


Initially Marc, you mentioned pelleted seeds. I was assuming this meant that all seeds would be the same size from the seeder’s point of view. There are a few possible issues with small seeds becoming jammed in the turnstile, also the turnstile would have to have very tight tolerances in its housing.

David Maher

Liberty University and FarmBot present an Open Source Collaboration Project: Seeder Pod Tool

After a number of design iterations and some great work the Liberty University FarmBot Project team has completed their work!

Here is the final video commercial of the new seeder pod tool design for use with pelleted seeds:

Please see the attached documentation and assembly instructions as well as the STEP files for 3D printing. This is completely open source hardware so feel free to edit, improve and modify for your own purposes.

The Seeder Pod tool uses a servo to turn the turnstyle and control the placement of the seed. To overcome the potential for seed jamming in the turnstyle mechanism we decided to use a bruit force method and overpower any risks associated with seed jamming. If a seed gets caught in the turnstyle and jams, this servo will simply crush the seed inside the turnstyle and clear the smaller broken pieces of the seed. There are many servo motors on the market, but this was the one that we selected for its strength and durability:

DS3225MG Servo Motor
High speed high torque Dimensions:1.57 x 0.78 x 1.59in (40 x 20 x 40.5mm)
Control Angle 270

Seeder_Tool_Brochure.pdf (1.5 MB)
The seeder tool brochure includes information on the basis for the design, tool assembly, programming and other information relating to the design development and decision gates of the project.

Here are the STEP files so that you can print your own.

Axle.STEP (27.3 KB) Main Body.STEP (1.3 MB) Screw.STEP (15.9 KB) Seeder Tool.STEP (1.9 MB) Servo.STEP (56.7 KB) Turnstile.STEP (57.0 KB) UTM.STEP (411.5 KB) White round piece.STEP (41.2 KB)


I love this thing. Though, it looks like a little too heavy for the magnets! :slight_smile:

Moreover how’s the current delivered for the stepper motor? Via the UTM Pins?

The servo motor is controlled by the Servo Motor controller directly on the Farmduino board. For this proof of concept demonstration project, the team used a direct 3 conductor wire going from the servo motor to the Farmduino board servo motor controller pins located at the bottom of the Farmduino. There is room for several servo motors to be controlled by the Farmduino micro-controller board.


However, in the future if FarmBot Inc was to release this as a tool offering in our kit, we would connect it up through the spare UTM pins and run all three conductors through the UTM.