Open Duck Mini V2 - Bipedal Robot

We are making a miniature version of the BDX Droid by Disney. It is about 42 centimeters tall with its legs extended. The full BOM cost should be under $400 !

BOM

-→ see pdf file attached for details. 

| Item | Price |
|------|-------|
| 15cm micro USB to USB-C cable | €7.00 |
| 18650 cell | €5.00 |
| 18650 cell holder | €4.99 |
| 2.1mm barrel jack | €1.00 |
| 2S BMS | €8.40 |
| 3D printing M3 inserts | €5.99 |
| 50cm micro USB to USB-C cable | €6.00 |
| 5V regulator | €4.00 |
| 9g servos | €3.33 |
| Amplifier | €5.00 |
| Bearing | €3.50 |
| Cable sheath | €9.00 |
| Eye diffusers | €0.16 |
| Feet contact switches (SS-10) | €4.00 |
| Feetech 7.4V STS 3215 | €14.00 |
| IMU (BNO055) | €40.00 |
| Flashlight LED | €0.20 |
| Microphone | €15.00 |
| Projector reflector | €2.00 |
| Raspberry Pi Camera | €5.00 |
| Raspberry Pi Zero 2 W | €26.08 |
| SD card | €10.00 |
| Servo control board | €5.00 |
| Small power switch | €4.49 |
| Speaker | €6.00 |
 

PRINT

All Parts in the correct quantity are in the mf3 print profile.

What part belongs where can be determined by its name in the object tab:

You also have a print guide here:
https://tnkr.ai/explore/docs/open-duck-mini/open-duck-mini-v2#print-guide

Assembly

You can find the guide here:

https://tnkr.ai/explore/docs/open-duck-mini/open-duck-mini-v2#assembly-instructions
https://github.com/apirrone/Open_Duck_Mini/blob/v2/docs/assembly_guide.md

(Chinese) https://zihao-ai.feishu.cn/wiki/space/7488517034406625281

You will need :

• A soldering iron, and basic electronics tools and skills
• X m3 screws (TODO : add the exact number)
• Some wire
• Loctite Threadlocker blue 243

Steps :

Assemble the trunk

Place the bearings in trunk_bottom like so, and insert M3 inserts in these holes. It's also a good time to insert the 4 M3 inserts in the bottom of this part to mount body parts later on.

Then assamble trunk_bottom and trunk_top, and screw them together with 2 M3x10 screws through these holes

Mount the middle motor like so and screw it with the plastic screws that came with the motors :

Insert roll_motor_bottom like this

Assemble the feet

Both feet are the same.

First, assemble foot_bottom_tpu with foot_bottom_pla. Insert M3 inserts in these holes :

And screw the two parts together with two M3x6 screws.

Then, insert M3 inserts in these holes in foot_top here :

And assemble everything like so. Make sure the driver side of the motor is on the foot_top part side :

You can add the foot switches like this too :

You press fit them so that the switch is activated when the foot touches the ground

Assemble the shins

Insert M3 Inserts in these holes of leg_spacer (on both sides. Insert 4 M3 inserts in total) :

Then, first plug the motor cable in the foot's motor, and make it go through the right_sheet like so

Then assemble like below:

Assemble the thighs

The thigh is pretty much the same thing, except the hip_pitch motor is mounted this way (important for the zero position)

Assemble the hips

Mount left_roll_to_pitch or right_roll_to_pitch, here the parts are symmetrical so you have to use the right one.

Mount roll_motor_top to the hip_yaw servo (screw from the bottom). Don't mount the servo to the trunk yet.

Then mount hip_roll like this

And insert the sub assembly like this

Screw everything you can (with the plastic screws provided with the servos)

You can now mount the leg like this :

And do the same for the other leg :)

Your duck should now look like this

Assemble the neck

You know the drill

Assemble the head mechanism

First, mount head_pitch_to_yaw like this

Then, independently mount head_yaw_to_roll and head_roll_mount to head_roll dof

(You can insert head_bot_plate and body_middle_top now too to avoid having to disassamble the head later)

Then

Then

Your duck should now look like this

Electronics

this is out of scope for makerworld,
but you can find a wireing and software guide here:
https://tnkr.ai/explore/docs/open-duck-mini/open-duck-mini-v2#electronics--wiring
https://github.com/apirrone/Open_Duck_Mini/blob/v2/docs/assembly_guide.md

Source:
https://github.com/apirrone/Open_Duck_Mini/tree/v2

Created by:
https://github.com/apirrone