2D Plotter Table Project

Overview

• I want to make a table with a 2d plotter inside that will be used to roll a marble through sand like a japanese garden Sisyphus industries made one that I am basing my design off of.

Current Status

• Prototype created
  • only the robit part has been made, tabletop and legs still need to be made
    • Add pictures here
• Code is basically completed just needs some optimization

Tasks

• Build Table
• Build Bot
  • ProtoType
  • Write Gcode Generator
  • make bot quiet
    • Replace controller
    • Remake rails?
  • [ ]
• Add Bot to table
• Completed Task

Log

2024-05-30

• Started working on motor calibration
• Encountered noise issues with motors

2024-05-19

• Implemented vpype library
• Removed deprecated scripts (main.py, svgConverter.py)

Resources

• vpype-gcode

Future Plans

• Implement custom functions in main.py
• Improve motor noise reduction
• Replace motor driver
• Make bot with higher quality plywood
• Optimize vpype script

Dependencies

• Raspberry pi:
  • flask
  • venv
  • python
  • grbl
  • UGS
  • pyserial
  • tmux

flask server is accessible from here: http://raspberrypi.local:5000

Notes Pre reformatting:

Printer: Monoprice Maker Select V2

Overview

• X and Y Axis Plotter: 250mm each

Firmware

• Type: Marlin G-code
• SD Card: Must be FAT32 formatted

Current Workflow

• drawing.gcode: Used as a buffer due to library limitations (returning an array)
• Library to Explore: vpype-gcode

File Usage

• main.py and svgConverter.py: No longer in use
• vpype.py: Utilizes the vpype library for current functionalities
  • Future Use of main.py: Writing custom functions callable at any time during the program

General Flow of main.py

1. Zero
2. Flatten sand
3. Pick up marble
   • Choose marble size
4. Start drawing at the closest point to the curve from the marble parking spot
5. Draw
6. Finish drawing
   • Options:
     • Flatten sand
       • Return marble
       • Do whatever flattens sand
     • Continue another drawing over it
     • Park marble

TODOS

• Motors Loud as Hell
  • Adjust current (lowered 10%)
  • Adjust feed rate (none worked)
    • 300 too quick
    • 100 too quick
    • 10 too slow
  • Replace control board with something better
• List Dependencies
  • Track correct files from vpype library
• Fix Curves from vpype
  • Starting
  • Optimize travel between curves

Trying to Make Motors Quiet

• Board: Melzi Hybrid A4988 V3.5 (embedded A4988 motor drivers)
  • Adjusting current: if unsuccessful, explore using an Arduino with robust motor controllers
  • Potential controllers: TMC2208 for smoother movements, R100 Resistors
• Motors: C17HD40102-01N BiPolar
  • 1.8 degrees per step
  • 1.02A
  • 0.62NM

Tuning Drivers for Noise Reduction (DID NOT WORK)

• Following this guide: Adjusting stepper motor current on Melzi Board
  • Target: 90% max current
  • Formula: VREF = Current(A) * 8 * SenseResistor(RS)
    • 0.82 = 1.02 * 8 * 0.1
    • 0.74 = 90% power
  • Initial values for each potentiometer: 0.67 (lower than max)
  • Reduced to 0.60 (by 10%) to see if it helps
  • Result: Noise reduction was minimal; further steps needed

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