Robotic Actuator EBA-17-S

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NEW UPDATED Version 2024 - Planetary Gears Actuator EBA-17-S for NEMA17

The EBA-17-S is the 2024-updated planetary gear actuator for NEMA17 stepper motors, at a 38.4:1 reduction ratio. It's the actuator used in the EB-65 and EB-15 arms.

For the model in STEP file https://toolboxrobotics.com/shop  

Efficiency                            Output Torque*

 70% (conservative)            13.44 Nm

 80% (typical)                       15.36 Nm 

 85% (optimistic)                 16.32 Nm

Typically 70–85% for 3D-printed planetary gears due to friction — real-world loss, not just a formality.

Efficiency                            Force at 200mm**

 70%                                       67.2 N

 80%                                       76.8 N

 85%                                       81.6 N

So realistically, expect somewhere around 67–82 N of force at 200mm from the joint, with ~77 N as a reasonable middle estimate. That's roughly 7–8 kg-force equivalent at that point.

A couple of caveats worth keeping in mind: this is the actuator's torque capability, not necessarily what the arm can safely sustain — your printed gears, shaft, and mounting hardware may fail before the motor's rated torque is reached, especially with PLA/PETG gears under repeated load. 

* Calculator based on a standard common model NEMA17 stepper motor of 0.5 Nm.

** Torque to force at your 200mm (0.2m) lever arm.

• Soldering Iron
• Hex key M3 

• 3D filament 1.75, 1KG, ±0.02 mm, PLA+ or ABS or PA-CF 

• Ball Bearings 6mm   20 PCS
  *You can use 6mm plastic balls from airsoft or Chrome steel for the ball bearing. 
• Synthetic Grease PERMATEX 

Screws, nuts & washers

• M3 Screws M3x8mm    6 PCS 
• M4 Nuts    4 PCS 

Inserts 

• M3 Inserts M3x4mm    4 PCS 

• Nema 17 Stepper Motor  1 PCS