ShapeokoCNC

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Shapeoko light cnc.jpg
Description Shapeoko Light CNC
Make Shapeoko
Manufacturer Link http://www.shapeoko.com/
Category Mechanics
Operational Status BROKEN
Received at 2012/11/20
Acquisition Details
Owner User:Peter

Overview

This machine has been taken home by Peter again, so there is currently NO CNC mill at TechInc. I (Wally) have ordered a ShapeOko2 (http://www.shapeoko.com/wiki/index.php/ShapeOko_2) and will be building that up, which will be at TechInc part of the time, for general use.

This is a light duty CNC based on the Shapeoko mechanics, which is itself based on the MakerSlide linear bearing system. Both are open hardware projects.

The mechanics are just the assembled version of the Shapeoko kit, as sold by Inventables. The X and Y-axes are belt/pulley driven and the Z-axis is driven by an M8 threaded rod. The effective working area is approximately 200mm x 200mm x 90mm.

Separately I had also purchased some NEMA-17 stepper motors, a 24V/15A power supply, and Arduino Uno and a grblShield (a motor shield designed to work with an Arduino-based g-code intepreter called GRBL, apparently pronounced like the English word "garble"). Together with the mechanics (and eventual software running on a computer), this should cover what is needed to set up a complete CNC platform.

I also have some extra bits of MakerSlide, V-wheels, etc. to allow for eventual modifications.

This is a generic light duty CNC platform and could in principle be used for a number of things. At least initially my idea is that we can set this up as a basic PCB milling platform that space members can use for quick PCB prototypes.

Status

The mechanics, with the stepper motors attached, is sitting on a shelf in the main room of the space. The 24V power supply, the Arduino/grblShield, cables and some extra mechanical bits are all in a project box labeled "PETER CNC Stuff". There is also a MDF "wasteboard" on top of the project box.

Additional notes

The stepper motor (Vexta PK243-01A) specs are: NEMA 17, 200 steps/revolution, 6-wire unipolar wired as bipolar (green goes with black as one coil, red goes with blue as the other coil, leave white/yellow center tap wires unconnected). The rated voltate is 5.6V and the rated current/phase is 0.67A. Each motor thus has 4 wires to connect to one of the grblShield connectors, as in the Connector Pinout. This implies the wires should be connected in the order {Green, Black, Red, Blue}, up to swapping the pairs corresponding to one or the other coil to get the polarities correct.

In the "PETER CNC Stuff" project box there is also a power strip with an on/off switch. Since the power supply itself doesn't have an on/off switch, the power supply should be plugged into the power strip in order to have a master switch (useful if there is some problem).

Things to do

Basic

  • Proper cabling (with some 4-conductor cables instead of the mish-mash which used some excessive ones I had around) and properly labeled cables/connectors
  • General tightening of bolts, belt tension adjustment and proper alignment (e.g. using eccentric nuts on the carriage plates)
  • Better clamps for the belts
  • I have a V2 grblShield, this requires the z-axis modification
  • Changes to the GRBL configuration
  • Adjusting the motor current
  • Attach a basic baseboard, e.g. a more solid piece of wood with some sacrificial MDF on top, plus some means of clamping things to the baseboard.
  • Small enclosure for Arduino/grblShield (+ perhaps power supply?) to protect them from debris
  • Testing/document some software workflow chain (such as this example, perhaps with TechInc logo)
  • Make adaptor for Dremel-tool or engraver (plus perhaps a pen/dial-indicator for testing)
  • Undoubtedly other things I've not thought of yet

Extra

  • Proper cable management
  • Add contact switches for limiting and perhaps to facilitate homing
  • Add a simple tooling plate to allow for quick placement/clamping of copper clad PCB's to a standard location
  • Build or acquire a proper mountable spindle (as opposed to an adapted hand-tool like a dremel)

Sun 4 May

We (friso and others) made the X motor move through the Printrun program.

Sun 27 Okt 2013

Today I (Wouter):

  • Hooked up the belts again
  • Hooked up all cables
  • Changed the grbl settings to:

$0=43.74453193350831 $1=43.74453193350831 $2=320 $3=30 $4=750 $5=1100 $6=64 $7=0 $8=9.8 $9=0.05

  • Adjusted the motor current for X axis. (Needs more testing)
  • Ran some test programs successfully!