P-CNC Plotter Disguised As a Quadruped Robot

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Introduction: P-CNC Plotter Disguised As a Quadruped Robot

About: PLC, Arduino - Do it yourself project

This is my P-CNC plotter which is laid out and disguised as a quadruped robot. Today, I'd like to share how I made it. It was quite simple, no 3D printer required, just need my meticulousness, care and a little patience.

Please check the brief description and how P-Plotter works in the video below before getting started.

Step 1: Supplies

Main components are as follows:

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  • 1pcs x Arduino CNC Shield V3 GRBL: Amazon - Banggood.
  • 3pcs x Stepper Motor Driver A4988: Amazon - Banggood.
  • 2pcs x Stepper motor NEMA 17: Amazon - Banggood.
  • 1pcs x Old CD/DVD Burner Writer Rom Player Drive - Compact Type: Amazon - Banggood.
  • 2pcs x Round Bar Shaft Rod Diameter 8mm, Length 400mm: Amazon - Banggood.
  • 2pcs x T8 Lead Screw 2mm Pitch, 8mm Lead , Length 400mm with Copper Nut: Amazon - Banggood.
  • 12pcs x Ball Flanged Shielded Bearings 8 x 22 x 7mm: Amazon - Banggood.
  • 1pcs x Aluminum Flexible Shaft Coupling, Inner Hole Size: 10mm x 10mm: Amazon - Banggood. It is used to clamp the pen/ pencil.
  • 2pcs x Aluminum Flexible Shaft Coupling, Inner Hole Size: 5mm x 8mm: Amazon - Banggood.
  • 2pcs x XH2.54mm – 4P 20cm Wire Cable Double Connector: Amazon - Banggood.
  • 1pcs x 5mm DC Female Power Plug: Amazon - Banggood.
  • 1pcs x Power Supply 12VDC: Amazon - Banggood.
  • 1pcs x Clear/White Acrylic, size A3, thickness 5~10mm: Amazon - Banggood.
  • 1 meter x 8P/16P Rainbow Ribbon Cable: Amazon - Banggood.
  • Some small cable ties, cable spiral wrap, bolts and nuts.

PVC pipes and its fittings:

  • 1 meter x PVC Pipe Ø42mm.
  • 1 meter x PVC Pipe Ø60mm.
  • 1pcs x Cross PVC Pipe Ø42mm.
  • 6pcs x End Cap PVC Pipe Ø42mm.
  • 6pcs x End Cap PVC Pipe Ø60mm.

Tools:

Softwares:

Step 2: Schematic

The schematic & connection diagram is very simple.

  • Plugging the CNC shield on the Arduino Uno R3.
  • Plugging three stepper motor drivers A4988 on the CNC shield at X, Y and Z label position.
  • Connecting the cables from stepper motor drivers to three stepper motors.

That's all!

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Step 3: Drilling and Cutting Works

Due to the COVID-19 pandemic, my city was locked down, I couldn't go out to buy materials and electronic equipments. So I had to use what remained in my hand, especially PVC pipes and its fittings.

Firstly, I imagined a robot-shaped CNC plotter and sketched it out on paper to estimate the pipe fittings. And I named it "P-Plotter" because it was made of PVC pipe. My P-Plotter shape looked like the picture below and my goal is to drill total 12pcs of PVC end cap Ø42 and Ø60mm to thread the leadscrews and shafts through these holes.

Drilling is the most important work of this project, deciding the success or failure. We should buy a few extra end caps in case of incorrect drilling. Because this inaccuracy is easy to happen when we drill by hand.

a. Drilling PVC end caps Ø42mm.

Firstly, I drilled a big 22mm diameter hole. I have marked its center by placing a bearing inside the end cap so that it was in contact with the wall of end cap. The small 8mm diameter hole's center was drilled with a distance of 23mm from the big hole's center. And two hole centers should align with the end caps center for a symmetrical mechanism.

Total 6pcs end caps Ø42mm were drilled with 2 holes.

b. Drilling PVC end caps Ø60mm.

  • I did the same way with end caps Ø60mm with total of 4pcs.

  • To mount the 2 stepper motors, I had to drill 4 more small holes on the end cap Ø60mm, around the big holes. Quantity needed: 2 pcs.

c. Cutting connecting pipes Ø42 & Ø60mm.

Connecting pipes should be cut in suitable length so that when we connected 2 end caps together, there is no gap between them.

  • Connecting pipe Ø42 quantity needed: 5pcs.
  • Connecting pipe Ø60 quantity needed: 3pcs.

After I connected 2 end caps together by a connecting pipe, it should be like this.

d. Cutting PVC cross Ø42mm

The PVC cross is a bit long so I had to cut it, about 28mm, to extend the XY axis working space.

Step 4: Inserting All Bearings and Copper Nuts Into the Drilling Holes

  • Inserting bearing into 22mm diameter holes.

  • Connecting 2 end caps and check whether it was aligned and symmetric together.

  • Inserting bearings and copper nuts into end cap Ø42 and connecting 4 end caps to PVC cross. We should check with lead screws and shafts before fitting all end caps tightly into cross. Note that, two lead crews and shafts of the X and Y axes should be arranged horizontally and vertically relative to each other. By this way, they could get through the PVC cross without touching each other.

  • The opposite side of cross.

  • And the side view.

Step 5: Y Axis Assembly Works

  • Mounting flexible coupling 5mm x 8mm on the steppers motor shaft.

  • Mounting stepper motor on the end cap and fixing lead screw into flexible coupling.

  • Connecting with another end cap and inserting a shaft into 8mm diameter hole.

  • Temporarily checking and aligning before fixing 2 end caps tightly at motor side.

  • Building Y axis by threading a lead screw and shaft through the PVC cross.

  • Locking the leadscrew end by one bearing and check the movement by hand.

Step 6: Control Board Pre-Assembly Works

I have mounted the control board in the center of P-Plotter. It is placed on the PVC cross as follows:

  • I cut a small acrylic sheet, drilled 4 holes for mouting Arduino Uno and other 2 holes for mounting to PVC cross.

  • I cut 2 small pipe support, 50mm diameter, about 25mm long. The pipe wall cutting side was used for clamping to PVC cross and the drilling holes side for mounting to Arduino Uno acrylic base above.

  • Connecting pipe supports to Arduino Uno acrylic base, just for testing.

  • These pipe supports should be clamped on the PVC cross before installing X axis, then later connected to the Arduino base by bolts.

Step 7: X Axis Assembly Works

  • I built X axis as same as the Y axis at stepper motor side. I mounted stepper motor on the end cap and fixed leadscrew into flexible coupling.

  • Clamping pipe supports on the PVC cross.

  • Installing X axis by threading its lead screw and shaft through the PVC cross.

Step 8: Z Axis Assembly Works

  • Soldering cable to CD drive stepper motor and mounting one flexible coupling 10 x 10mm on the front side to clamp the pen.

    • On the back, I attached the CD stepper motor frame to a small acrylic sheet and mounted this acrylic sheet to end cap Ø42mm.

    • Threading the lead screw and shaft through the end caps and locking the lead screw by bearing inside and outside of end cap.

    • Z axis was done!

  • Step 9: Control Board Mounting Works

    • Mounting control board base to pipe supports and tightening 2 bolts.

    • Connecting all cables from stepper motors to CNC shield. These cables are fixed by cable ties and cable spiral wraps.

    • With this design, when P-Plotter working, the X-axis would slide back and forth so I used a wall calendar cover which is very flat, smooth and hard enough, as a working surface. Or we can use an A4 size acrylic sheet.

    Step 10: GRBL Firmware Uploading and Parameter Setting

    1. Uploading GRBL firmware to Arduino Uno.

    • Download GRBL firmware files.
    • Copy GRBL folder to C:\Users\Administrator\Documents\Arduino\libraries\
    • Open Arduino IDE, from File menu click ExamplesGRBLgrblUpload.
    • Select the correct Port and Board (Arduino Uno) Compile and Upload the code to Arduino Uno.

    2. GRBL parameters setting for my P-Plotter are as follows:

    $010.000Step pulse time
    $125.000Step idle delay
    $20.000Step pulse invert
    $30.000Step direction invert
    $40.000Invert step enable pin
    $50.000Invert limit pins
    $60.000Invert probe pin
    $101.000Status report options
    $110.010Junction deviation
    $120.002Arc tolerance
    $13

    0.000

    Report in inches
    $20

    0.000

    Soft limits enable
    $21

    0.000

    Hard limits enable
    $22

    0.000

    Homing cycle enable
    $23

    0.000

    Homing direction invert
    $2425.000Homing locate feed rate
    $25500.000Homing search seek rate
    $26250.000Homing switch de-bounce delay
    $271.000Homing switch pull-off distance
    $301000.000Maximum spindle speed
    $310.000Minimum spindle speed
    $320.000Laser-mode enable
    $100200.000X-axis travel resolution
    $101200.000Y-axis travel resolution
    $10253.333Z-axis travel resolution
    $110500.000X-axis maximum rate
    $111500.000Y-axis maximum rate
    $112500.000Z-axis maximum rate
    $1205.000X-axis acceleration
    $1215.000Y-axis acceleration
    $1225.000Z-axis acceleration
    $130150.000X-axis maximum travel
    $131150.000Y-axis maximum travel
    $13240.000Z-axis maximum travel

    The parameters which I have done the calibrations are highlighted in table above.

    The acceleration parameters $120 and $121 should be set to a small value, to prevent shaking issues.

    Step 11: Inkscape & Universal Gcode Platform

    1. Inkscape

    To export Gcode files from a image, I followed these steps:

    - From the Inkscape menu go to FileProperties and in the Page Tab to set the Page Size.

    - Import a seleted image by using the menu File ‣ Import. In the menu, go to Path ‣ Trace Bitmap and convert the Object to Path.

    - Go to Extensions ‣ Gcodetools ‣ Tools Libary. Select Tools Type and click Apply.

    - Go to ExtensionsGcodetoolsOrientation Points

    • Orientation type: 2 - points mode.
    • Z Surface: 0.0mm. This is the top of your paper surface.
    • Z Depth: -1.0mm. This is working position of Z axis when P-Plotter is drawing object. This negative number ensure that the pen tip can touch the paper.

    - Go to Extensions ‣ Gcodetools ‣ Path to Gcode

    • Z safe height: 2mm. It is safety height above the plotting surface when moving between drawing points.
    • Click the Path to Gcode Tab before clicking Apply. This creates the G-code file.

    For the first testing, I expected my plotter to write its name "P-CNC PLOTTER" so I created a G-code file for this text.

    2. UGS - Universal Gcode Platform

    - Instructions:

    • Open Universal Gcode Platform, select Port and set Baud to 115200, click on Connect tab.
    • Select the appropriate position by moving X axis left - right, Y axis forward - backward and set the original coordinates by button Reset Zero.
    • Click OpenBrowse to the G-code file that generated by Inkscape.
    • Click Send and P-Plotter will perform drawing picture following the G-code.
    • Monitor the P-Plotter in action on the Visualizer tab.

    - I opened the G-code file for the above text "P-CNC PLOTTER".

    Step 12: Testings

    The result was not bad! You can check it on the introduction video. I loved its shape & movement during operating.

    And this is the second test.

    I have also tested with an image.

    Step 13: Conclusion

    I've seen a lot of projects related to XY plotters which were built with 3D printers. There are still many creative ways if we do not have a 3D printer at hand. Related to my P-Plotter, if we don't like the leadscrew driven system, we can switch it to a belt driven system like normal plotters that have been posted on many forums.

    Thank you for reading my works and hope you enjoyed my post this time!!!

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      16 Comments

      0
      trobins20200
      trobins20200

      1 year ago

      Impressive. Few people take enough time to document their projects like you have. You are to be commended for doing so. I have placed this one in my "someday" project file. Thanks.

      0
      tuenhidiy
      tuenhidiy

      Reply 1 year ago

      Thank you!

      0
      avinashk
      avinashk

      1 year ago

      good work dear. very neat clean and tidy... keep it up.. keep posting

      0
      tuenhidiy
      tuenhidiy

      Reply 1 year ago

      Thank you for being interested in my project!

      0
      masoud256
      masoud256

      1 year ago

      Very nice!
      it's a brilliant idea.

      0
      tuenhidiy
      tuenhidiy

      Reply 1 year ago

      Thank you!

      0
      kimtyson
      kimtyson

      1 year ago on Step 13

      Nice design! The criss-crossing axis idea is very cool.

      0
      tuenhidiy
      tuenhidiy

      Reply 1 year ago

      Thank you. I’m glad you liked it.

      0
      MaciejG17
      MaciejG17

      1 year ago

      +1 for showing ingenuity with the PVC pipes rather than just throwing a 3D printer at the problem at hand :)

      0
      tuenhidiy
      tuenhidiy

      Reply 1 year ago

      Thanks!

      0
      mwitherspoon
      mwitherspoon

      1 year ago

      Using PVC for the structure is awesome!
      Great work!

      0
      tuenhidiy
      tuenhidiy

      Reply 1 year ago

      Thank you!

      0
      anbuselvanp
      anbuselvanp

      1 year ago

      Awesome design and clear instructions! 👍

      0
      tuenhidiy
      tuenhidiy

      Reply 1 year ago

      Thank you!!!

      0
      AlexandreD64
      AlexandreD64

      Tip 1 year ago on Step 13

      Bonjour,
      votre projet semble intéressant, je vais certainement testé, merci.

      0
      tuenhidiy
      tuenhidiy

      Reply 1 year ago

      Thank you and have fun with your own-built P-Plotter ASAP.