Hand Grip Trainer (adjustable)

This is a fully 3D printed modular grip trainer designed for progressive hand and forearm strength development.

The resistance level can be adjusted by changing the number of installed spring modules and by selecting different spring widths. The system allows smooth operation even under slight hand misalignment thanks to the guided sliding handle. The spring geometry is optimized for high fatigue resistance and has been tested over thousands of repetitions.

Two spring variants are included:

• 10 mm width – higher resistance

• 8 mm width – reduced resistance

Based on testing, one 10 mm spring provides approximately 6 kg of resistance  The total resistance increases proportionally with additional springs installed.

Printing Instructions

All parts are designed to be printed flat on the build plate without supports.

Frame & Sliding Handle

• Material: PLA or PETG

• 0.4 mm nozzle

• 0.2 mm layer

• Infill: 20% is sufficient

• No supports required

• Print flat on the bed

Springs

• Material: tested with TPU 95A (Different TPU types may slightly change the overall resistance)

• Infill: 100% required

• 0.4 mm nozzle

• 0.2 mm layer

• Print flat on the bed

Who is it for?

This grip trainer may be useful for:

• Mountain hiking and alpine climbing preparation

• Rock climbers and boulderers

• Calisthenics and bodyweight training

• Martial arts practitioners

• Musicians (guitar, bass, drums)

• Rehabilitation and forearm strength recovery (light resistance setup)

• Anyone looking to improve grip strength and hand endurance