EvoArm
B✓ Links verified Jun 10, 2026
Guides and BOM only — orobot firmware does not yet support this hardware.
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159 stars on GitHub.
EvoArm is an open-source 3D-printable desktop robotic arm by Ali Shug, based in part on Armatec's LiteArm i2 (Thingiverse 480446). 3+2 DOF: three Dynamixel AX-12/AX-18A smart servos drive the main arm linkage, and two XL-320 servos drive a 2-DOF wrist effector. Source: https://github.com/AliShug/EvoArm
Hardware:
- 3 main DOF: Dynamixel AX-18A (recommended) or AX-12 smart servos
- 2 wrist DOF: Dynamixel XL-320 servos
- Arduino Mega 2560 controller (multiple hardware UARTs)
- 74LS241 tri-state buffer for multiplexing servo data lines
- Optional Arduino Uno setup using software-serial trick
Software:
- Python + PyGame inverse kinematics application (PyIK)
- 3D target position + end-effector orientation control
- Linear interpolation, bounds checking, reach-volume visualization
- UDP command interface for external control programs
License: CC-BY-SA 3.0.
Printing
The print set is the complete 32-part EvoArm design from AliShug/EvoArm (Design/). All parts are single-print (x1) unless noted; the arm uses several left/right mirror pairs — both halves are required, they are not interchangeable alternates.
Mirror pairs (print both — L and R):
Arm - shoulder-L/Arm - shoulder-RArm - main-arm-L/Arm - main-arm-RArm - actuator-hinge-L/Arm - actuator hinge RArm - effector left v2/Arm - effector right v2
Main linkage: Arm - base-center-support, Arm - mounting-bottom, Arm - mounting-top, Arm - main-arm-spacer, Arm - parallel-hinge, Arm - parallel-linkage, Arm - actuator-linkage, Arm - stabilizer-linkage, Arm - forearm v2 1, Arm - forearm v2 2, Arm - forearm v2 hinge.
Base: Base Plate, Base Join, Base Shaft.
Effector / wrist: Effector - Hinge 1, Effector - Hinge 2, Joint Lower, Joint Upper, Cap plate, Touchplate.
Bearings & spacers (print as many as the build needs): Arm - 608 bearing cap [Med], Arm - 608 bearing cap [Small], M4-608 Flanged Spacer, M4-608 Straight Spacer — these are small support parts used at multiple 608-bearing joints; print extras as required.
Cleanup note: the imported list previously held 32 entries but only ~20 unique parts — 12 parts were duplicated under opaque orobot-upload-<UUID>.stl names while 12 other upstream parts (base, effector, hinges, forearm v2) were missing entirely. The duplicates were removed (verified by byte-size match) and the 12 missing parts re-added from upstream, giving a clean, complete, human-readable 32-part set that matches the canonical EvoArm design. Servos (3x Dynamixel AX-18A + 2x XL-320), the Arduino, and electronics are sourced from the BOM, not printed.
🖨 Print Files (32)
Arm---base-center-support.stl
Arm---mounting-bottom.stl
Arm---mounting-top.stl
Arm---shoulder-L.stl
Arm---shoulder-R.stl
Arm---main-arm-L.stl
Required Hardware
| Item | Qty | Unit Cost | Notes |
|---|---|---|---|
| Dynamixel AX-18A smart servo | 3 | $90.00 | Main joints (AX-12A also supported but underpowered) |
| Dynamixel XL-320 smart servo | 2 | $25.00 | Wrist / end-effector |
| Arduino Mega 2560 Rev3 | 1 | $40.00 | Primary controller (Uno/Nano alternative) |
| 74LS241 tri-state buffer IC | 1 | $1.50 | Multiplexes servo control lines |
| 12V 5A DC power supply | 1 | $20.00 | (inferred) Powers Dynamixel bus |
| 3-pin TTL servo cables (Dynamixel) | 5 | $3.00 | (inferred) Connect daisy-chained servos |
| Breadboard or perfboard | 1 | $8.00 | (inferred) Buffer IC wiring |
| Jumper wire kit | 1 | $7.00 | (inferred) Logic-level connections |
| M3 fastener kit | 1 | $10.00 | (inferred) Joint and mount screws |
| Servo horn / bracket hardware | 1 set | $15.00 | (inferred) AX-series F-brackets |