Hsiwu Bat Flapping-Wing Robot
A biomimetic bat flapping-wing robot with three independently driven wing segments per wing, controlled entirely by analog electronics without a microcontroller.
- Other
- Open source
- 3D printable
Suggested by Robotheca, created by @Robusr (opens in a new tab), from github.com/Robusr/Hsiwu (opens in a new tab). Pinned to commit 1d61645 (opens in a new tab).
- Hardware license
- MIT (opens in a new tab)
- Software license
- MIT (opens in a new tab)
- Commercial use
- Allowed
Photo and 3D model
3D preview converted from github.com/Robusr/Hsiwu at 1d61645, under MIT. View the original files from GitHub (499 KB) (opens in a new tab)
- Power
- 3.7 V
- Reach
- 205 mm
- Weight
- 17.81 g
What it can do
Written by Robotheca from the project's documents.
- Flaps three independently driven segments per wing, mimicking bat wing membrane deformation
- Flapping frequency set at about 4.8 Hz by the NE555 RC timing networks
- Lead-screw scissor mechanism expands and contracts the wing membrane area
- Fully analog control with no microcontroller and no firmware
- Flapping rate can be fine-tuned with trimmer resistors on each NE555 stage
Bill of materials
17 parts17 of 17 parts shown
| # | Component | Quantity | Est. price | Supplier |
|---|---|---|---|---|
| 1 | 3D-printed parts (ABS/PLA) | – | – | – |
| 2 | M2 countersunk screws (10/12/14/18 mm) | – | – | – |
| 3 | M2/M3 lock nuts | – | – | – |
| 4 | Miniature ball bearings | – | – | – |
| 5 | DC hollow-cup geared motors | 3 | – | – |
| 6 | 3.7V LiPo battery | 1 | – | – |
| 7 | NE555 timer (SOIC-8 equiv., on SOP-20 carrier) | 3 | – | – |
| 8 | 74HC04 hex inverter (SOIC-14) | 1 | – | – |
| 9 | L293D dual H-bridge driver (SOIC-8 equiv.) | 3 | – | – |
| 10 | MT3608 boost converter (SOT-23-6) | 1 | – | – |
| 11 | Resistors, capacitors (0805) | – | – | – |
| 12 | Schottky diode (SMC) | 1 | – | – |
| 13 | Power inductor (SMD, 7.3×6.8 mm) | 1 | – | – |
| 14 | Adjustable resistors (SMD trimmer) | 3 | – | – |
| 15 | XH-2A 2-pin header (P2.50) | – | – | – |
| 16 | Slide switch (SS12D07VG4) | 1 | – | – |
| 17 | Indicator LED (0805) | 1 | – | – |
17 of 17 parts have no price in the source, so there is no parts total. Read from README.md at the pinned commit.
Build guide
The creator's steps, each with its instructions.
- 1Solder all components onto the custom PCB according to the schematic
- 2Connect the three motor wires to the XH-2A headers on the PCB
- 33D-print the structural frame parts
- 43D-print or laser-cut the linkage rods
- 5Assemble the frame using M2/M3 screws, lock nuts, and miniature bearings
- 6Mount the PCB onto the central support chassis
- 7Insert the 3.7V LiPo battery and flip the power switch
The guide appears here as you scroll.
Guide by @Robusr (README.md), under MIT.
More guides
Wiring and electronics
Notes written by Robotheca from the project's documents.
Main parts
- Three NE555 timers configured as astable oscillators (SOP-20 carrier)
- 74HC04 hex inverter for phase inversion of the timer outputs
- Three L293D dual H-bridge drivers, one half-bridge channel per motor
- Three DC hollow-cup geared motors with four-stage planetary reduction
- MT3608 boost converter raising 3.7 V to about 7.35 V for the motors
- On-board LDO regulator providing 5 V for logic
- 3.7 V single-cell LiPo battery with slide power switch and green indicator LED
- Schottky diode for reverse-polarity protection
Connections
- Battery feeds the MT3608 boost converter through a Schottky diode and the power switch SW2
- Boosted 7.35 V supplies the L293D motor drivers; LDO supplies 5 V to the logic ICs
- Each NE555 output drives one channel of the 74HC04, giving complementary signals for the opposing half-bridge
- Each L293D half-bridge drives one motor through XH-2A 2-pin connectors on the PCB
- Trimmer resistors R4, R10 and R11 set the RC time constant of each NE555