The Penny Trainer – Adjustable LST Plant Trainer

The Penny Trainer is a simple adjustable plant training tool that uses stackable pennies as weights to gently pull branches downward for low stress training (LST). Each penny weighs about 2.5 grams, making it easy to fine-tune the amount of tension applied to a branch by simply adding or removing coins.

This was my first original design from scratch, created because I wanted a training solution that could be used both indoors and outdoors without the downsides of traditional methods. Instead of pushing stakes into the soil or forcing harsh bends with typical LST clips, the Penny Trainer spreads the bend across the entire branch, creating a smoother and more natural curve that keeps growth lower and more parallel with the ground.

Because the branch isn't tied down rigidly, it can still move naturally with the airflow from fans, reducing stress and helping avoid issues like branches being held too tightly or growing too close to lights. This allows for a more natural training method while still guiding the plant structure exactly where you want it.

Simply hook the trainer onto a branch and add pennies until the desired amount of downward pull is achieved. As the plant grows, you can easily adjust the tension by adding or removing coins.

Simply hook the trainer onto a branch and add pennies until the desired amount of downward pull is achieved. As the plant grows, you can easily adjust the tension by adding or removing coins.

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Print Settings

Printer:
Any standard FDM 3D printer

Material:
PLA recommended (PETG also works)

Layer Height:
0.20 mm

Walls:
3

Infill:
15–25%

Supports:
None

Brim:
Optional

Orientation:
Print flat on the build plate.