Omni Wheel CNC Plotter Upgrade

The following improvements have been made to my instructable https://www.instructables.com/Omni-Wheel-CNC-Plot...

Improvements:

• The 1N4007 diode has been replaced with a MBR735 35V 7A diode.
• The plotter speed is now the same in both the X and Y directions.
• Higher resolution
• The ability to rotate

In addition the following commands have been added for use in future projects

• ML move 1-step to the left
• MR move 1-step to the right
• MF move 1-step forward
• MB move 1-step back
• RL rotate 1-step CCW (counter-clockwise)
• RR rotate 1-step CW (clockwise)

Arduino pins A0 and A1 may also be used for course correction.

• Pulling pin A0 low will cause the plotter to steer left.
• Pulling pin A1 low will cause the plotter to steer right.

The parts list is the same as for https://www.instructables.com/Omni-Wheel-CNC-Plot... except that the 1N4007 1A diode is replaced with an MBR735 35V 7A diode.

The cost of this project is the same.

The wiring changes are shown in green.

The Big Easy Driver M3 pin for wheel 1 is now connected to Arduino pin 7 instead of ground.

• Normal operation requires a wheel speed ratio of 2:1. This is achieved by setting Arduino pin 7 LOW.
• Rotation of the chassis requires a wheel speed ratio of 1:1. To achieve this we set Arduino pin 7 HIGH

Arduino pins A0 and A1 are now INPUT_PULLUP. This feature will be used in future projects.

• Dragging pin A0 LOW causes a rotate left (RL) instruction to be inserted between g-code instructions which cause the plotter to steer left.
• Dragging pin A1 LOW causes a rotate right (RR) instruction to be inserted betweeen g-code instructions which cause the plotter to steer right.

The current rating of the reverse voltage protection diode has also been increased. An MBR735 7amp diode replaces the original 1N4007.

Except for the rotate instructions, the attached software, is backward-compatible with my original plotter described in instructable https://www.instructables.com/Omni-Wheel-CNC-Plot...

Installation

• Download the attached file “omni_wheel_cnc_plotter_v9 “
• Copy the contents into a new Arduino sketch ... use a text editor NOT a word processor
• Save the sketch ... any name
• Now compile and upload the sketch to your Arduino.
• Left-click “Tools/Serial Monitor”
• Set the baud speed to 9600
• You should now see a menu shown in photo1

The following hardware and software changes have been made to the omni-wheel plotter described in instructable https://www.instructables.com/Omni-Wheel-CNC-Plot...

• Improved resolution
• The speed is now the same for the X and Y axes
• A wiring change allows the plotter to rotate
• The plotter may be steered using Arduino pins A0,A1
• The current rating of the reverse voltage protection diode has been increased

In addition the following instructions have been added to support future projects.

• ML move 1-step to the left
• MR move 1-step to the right
• MF move 1-step forward
• MB move 1-step back
• RL rotate 1-step CCW (counter-clockwise)
• RR rotate 1-step CW (clockwise)

  Click here   to view my other instructables.