3D Printed RC Excavator (UPDATED)

I love what ProfessorBoots (https://www.printables.com/@ProfJohnny_823077) has done for the 3D printing community.  Please support ProfessorBoots for all of his work to make these models come to life.  It does take hundreds of hours to make these models, electronics, and software.  https://professorboots.com/products/professorboots-workshop-pass

This is an excavator that is scaled to work with the 3D Printed RC Skidsteer (https://www.printables.com/model/721244-3d-printed-rc-skidsteer-v30) and 3D Printed RC Articulated Dump Truck (https://www.printables.com/model/1189649-3d-printed-rc-articulated-dump-truck).  

I like to create 3D models that follow these criteria:

• Do not require supports – I HATE supports.
• Print quickly – optimized for 0.4mm nozzle diameter with 2 exterior wall thickness
• Are easy to access for maintenance – I like to upgrade parts, but I hate to disassemble the entire model just to change out one part.
• Are chamfered on the bottom layer – this helps those who don't have a perfectly aligned bed and may still have “elephant foot” artifacts.
• Do not waste plastic – many designers make parts that are WAY thicker than are required for structural strength.  This just makes the parts bulky and take longer to print.

Notes

• NO SUPPORTS REQUIRED
  • All parts print without supports.
• Parts 1 - 13 are printed in gray PLA.
• Part 14 is printed in 95A Flexible TPU filament,
  • I recommend slowing down print speed and adding extra retraction.
• Parts 15 - 20 are printed in your favorite PLA color (I used construction yellow).
• Parts 21 - 29 are printed in black PLA.
• There are 2 options
  • Bucket - part 30 is printed in black PLA.
  • Claw - parts 31 - 38 are printed in black PLA.
• Part 39 can be printed in any color PLA to match your circuit board.
• You will need a controller compatible with BlueStack32 (XBox One, Playstation 4/5, etc.)
  • Refer to https://bluepad32.readthedocs.io/en/latest/supported_gamepads/

Building Instructions

• Bill of Materials, Software, Printed Circuit Board, and Assembly instructions can be found here: https://github.com/swholmstead/Excavator

Compatibility of Circuit Board

For most of my models, you can interchange my PCB with Prof Boots' PCB.  Unfortunately, this does not work for the Excavator software.  You can use Prof Boots' PCB (it will fit), but you need to use his software.  If you use my PCB, you need to use my software.

Prof Boots said that there were not enough GPIO pins to drive all of the outputs needed, so he decided to multiplex several of the DRV8833 inputs from a single GPIO pin with an additional chip. 

I was able to redesign the board and get enough GPIO pins to drive everything without needing to add an additional chip. For example, he was using 2 GPIO pins to drive the LEDs, and one GPIO pin was ALWAYS set to LOW. I wired that side to ground and freed up that GPIO. I was also able to use one of the GPIO pins that is used during boot and is not normally recommended for use. If used with a motor, the motor would randomly spin during boot, which would not be good. I found that you can use that GPIO pin to drive the LEDs with the only side effect being that the LEDs turns on during boot. Otherwise, it works just fine.

So, our use of GPIO pins is very different and are not directly interchangeable. That is not to say that you couldn't change my software to use the same GPIO configuration that Prof Boots used, but that task would not be trivial.

Updates

• 30 September 2025 - Added screws to keep cab in place.  Parts 15, 28 changed.
• 28 September 2025 - Made swivel motor and lock much stronger.  Parts 21, 22, 23 changed.
• 23 September 2025 - Reversed claw open/close buttons on controller.  File Excavator_Bluepad.ino changed.
• 22 September 2025 - Modified parts so Boom can raise higher.  Parts 12, 23 changed.
• 21 September 2025 - Updated schematics to switch connectors for swing and claw.  File Gerber_Excavator_PCB.zip changed.
• 20 September 2025 - Completed assembly instructions.

I redesigned so that it can be printed with NO SUPPORTS REQUIRED and is optimized for 0.4mm nozzle to minimize print times.