DrawBot – Calibration

Polargraph Calibration by Sandy Noble

Polargraph Calibration by Sandy Noble

Calibrating my DrawBot was apparently important to its operation.  Who knew?!  If you’re following along at home, you’ll definitely want to check out Sandy Noble’s instructible on Polargraph calibration.  I’ll put my settings here, but they probably won’t be that helpful to you unless you’re using the same exact equipment and hardware as I am.

  • Setup->MM per Rev = 50
    • Based on the actual spool center diameter, this should be 47.  But, with some line wound onto the spool, it should be more like 54.  So, of course, I chose something that was neither.
  • Setup->Steps Per Rev = 400
  • Setup->Machine Width = 844
    • Although the “Machine Width” is defined by Sandy as “The distance between the two closest points on the sprockets,” I used a different figure.1  Since my machine uses spools, rather than sprockets, and the spools are unwound on the far side of the spool, I measured from the far edge of the spool’s core the the other far edge of the other spool’s core.  I figure this is probably the best measurement of the width of the line available to the machine.
  • Setup->Machine Height = 848
    • This is a relatively arbitrary specification given that my spools have about four times as much filament than I could use in my current configuration.  I intended this to be 844, but must have typed it in wrong.  :)
  • Setup->Page Width = 216
    • Rounded up from 215.9, which is 8.5 inches converted to millimeters.
  • Setup->Page Height = 279
    • Rounded from 279.4, which is 11 inches converted to millimeters.
  • Setup->Pen Tip Size = 0.12
    • With my 2’x4’x0.5″ board covered in butcher paper, I’ve marked out on the paper the locations of the various important lines for my machine.
Posts in the DrawBot Adventure Series
  1. Wanna make a DrawBot?
  2. DrawBot, the Adventure Begins
  3. DrawBots for the slow learner
  4. DrawBot - Parts Ordered!!!
  5. DrawBot - The Breakdown
  6. DrawBot - Parts Shipped!!!
  7. DrawBot - The Plan!
  8. DrawBot - The Hacks
  9. DrawBot - The Delivery, Part II
  10. DrawBot – The Delivery, Part III
  11. DrawBot – The Assembly, Part I
  12. DrawBot – The Software, Part I (and an existential conversation)
  13. DrawBot – The Delivery, Part IV
  14. DrawBot – The Assembly, Part II
  15. DrawBot – The Assembly, Part III
  16. DrawBot – The Assembly, Part IV
  17. DrawBot – Halp!!! No - seriously, a little help?
  18. DrawBot – The Face Palm
  19. DrawBot – The Delivery, Part V
  20. DrawBot – The Silver Lining of Failure
  21. DrawBot – The Delivery, Part VI
  22. DrawBot – The Assembly, Part V
  23. DrawBot – The Assembly, Part VI
  24. DrawBot – Printed Parts
  25. DrawBot – The Assembly, Part VII
  26. DrawBot – The Breakdown, Part II
  27. DrawBot – Printing!
  28. DrawBot – Printing, Part II
  29. DrawBot – Why are you crying?
  30. DrawBot – Calibration
  31. DrawBot – Pen Selection
  32. DrawBot – How to Recover from a Stalled Print!
  33. DrawBot – Drawing Success(ish)!!!
  34. DrawBot – Pen Selection, Part II
  35. DrawBot – Onwards and Upwards!
  36. DrawBot – Another Successful(ish) Drawing!, and an Update
  37. Restarting a Stalled DrawBot Drawing
  38. Speedier DrawBot Drawings
  39. Two new DrawBot links! And an update!
  40. Excellent DrawBot Slides
  41. Another Drawing Robot!!!
  42. DrawBot Practice Tip: A Watched Pot
  43. The biggest inkjet printer ever
  44. Why do DrawBots draw on walls?
  45. Maze Code + Polargraph?
  46. Ideas for improving my DrawBot
  47. DrawBot Aesthetic Re-Design Ideas
  48. The Eagle Has Landed
  49. I think I know what I want to draw next...
  50. This project is not going to overengineer itself
  51. Overengineered Spools
  52. Overengineered Stepper Motor Mounts, Filament Guides
  53. Overengineered Bolt Endcaps, Case Holder
  54. Sourcing DrawBot Parts
  55. DrawBot - A Tour!
  56. DrawBot - A Preview
  57. Arduino Powered Drawing Robot Poll
  58. Building an Arduino Drawing Robot - On The Cheap
  59. DrawBot - Printed Parts Tour
  60. Unidentified Foam Object
  61. DrawBot, now ACTUALLY wall mounted!
  62. A Study of Drawing Robot Pen Holders and Design Considerations
  63. Drawing Robot Pen Holders, Calligraphy Pens, and Thought Experiments
  64. Ideal Qualities in a Drawing Robot Pen Holder
  65. Enough talk! Finally a pen holder!
  66. DrawBot Pen Holder Post Mortem
  67. To Maker Faire!!!
  68. Skipping! How could I forget the skipping?!
  69. Drawing Robot Penmanship
  70. PlotterBot at Maker Faire Bay Area 2013!
  71. PlotterBot.com - a new site dedicated to drawing robots
  1. Heaven forbid I do something normal, right? []

2 Responses to “DrawBot – Calibration”

  1. terance says:

    I just built a drbo. Any suggestions on how to calibrate it? I am trying to use the directions for the polargraph, but it seems wonky. In the drbo, the sprokets are below the drawing area and I can’t seem to find anything online.

  2. MakerBlock says:

    @terance: Have you reached out to Stuart Childs? He designed the DRBO robot to use Sandy Noble’s polargraph software. I would think that if you used Stuart’s design files and built yours accordingly, you could just use his setup?

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