Jacks Crafts

Wood Working

CNC Tips and Help

JacksCrafts CNC G Code Post Processor

I made my own processor to use in VCarve. It is a nice simple program for Do It Yourself CNC users like me who built their own CNC router. The generic g-code processors on and VCarve / Vectric Aspire did not have the tool notes on the top. And since I do not have a tool changer ( ATC ) I did not see the since in using other post processors that had the extra stuff I did not need.

I made one for Inches and one for MM with arcs. I set the file extension to .nc but I can change it to .tap (Mack3/4) if you want. I use an Arduino GRBL machine with NetBeans ( Universal G-Code Sender ) Click the thumbnail to enlarge.

I own the copyright to this program but you are welcome to use if for free for your own personal use. Use this at your own risk – so make sure you test it with a dry run before trying it out on an actual project.

Here are some links:

Go to GRBL and click on the code tab, then you will see the download button.
https://github.com/gnea/grbl/wiki

How do you pronounce Grbl!?

This is probably the number one question, and the answer is: “It depends on who you ask.”

When Simen Svale Skogsrud first sat down and wrote Grbl in 2009, he named it after a bigger version of a computer mouse. It’s small, useful, and doesn’t do much other than what its designed to do. So, if you ask him, it’s pronounced like “gerbil“. If you ask Sonny Jeon, the developer since 2011, he’d say it’s pronounced ‘grr-ble‘, because he was teased too many times by his wife when working on the project. quote from GitHub.

Go to github to get UGS. I like the nightly build myself.

https://winder.github.io/ugs_website/

NotePad++ is a nice free editor for your gcode

https://notepad-plus-plus.org/

Prusa has some calcualtors for setting your resolutions. https://www.prusaprinters.org/calculator/

Adding a Zero or Corner Touch Plate with CNC Shield

I decided to build a new CNC machine with all Ball Screws

Found out I needed bigger drivers so I am using the TB6600. This meant I can use Arduino UNO but without the cnc shield. For the touch plate / Z probe use the A5 with GND.

If you are using a CNC shield on an Arduino UNO you may wonder why everyone tells you to use the A5 pin on the arduino when it is covered up by the shield.

This diagram of the CNC shield shows where the A5 pin connects the 2 together. So you use the 1st and 3rd pin. Dupont connectors are used, where you see the red and green dot on this diagram. The blue dot (I believe) can be used to run an indicator light.

Here is the GRBL settings on my machine.

Copied from UGS 05-20-2019

**** Connected to COM3 @ 115200 baud ****

Grbl 1.1f [‘$’ for help]

>>> $$

$0 = 10 (Step pulse time, microseconds)

$1 = 255 (Step idle delay, milliseconds)

$2 = 0 (Step pulse invert, mask)

$3 = 0 (Step direction invert, mask)

$4 = 0 (Invert step enable pin, boolean)

$5 = 0 (Invert limit pins, boolean)

$6 = 0 (Invert probe pin, boolean)

$10 = 1 (Status report options, mask)

$11 = 0.010 (Junction deviation, millimeters)

$12 = 0.002 (Arc tolerance, millimeters)

$13 = 1 (Report in inches, boolean)

$20 = 0 (Soft limits enable, boolean)

$21 = 0 (Hard limits enable, boolean)

$22 = 0 (Homing cycle enable, boolean)

$23 = 0 (Homing direction invert, mask)

$24 = 25.000 (Homing locate feed rate, mm/min)

$25 = 500.000 (Homing search seek rate, mm/min)

$26 = 250 (Homing switch debounce delay, milliseconds)

$27 = 5.000 (Homing switch pull-off distance, millimeters)

$30 = 30000 (Maximum spindle speed, RPM)

$31 = 0 (Minimum spindle speed, RPM)

$32 = 0 (Laser-mode enable, boolean)

$100 = 80.000 (X-axis travel resolution, step/mm)

$101 = 80.000 (Y-axis travel resolution, step/mm)

$102 = 400.000 (Z-axis travel resolution, step/mm)

$110 = 1500.000 (X-axis maximum rate, mm/min)

$111 = 1500.000 (Y-axis maximum rate, mm/min)

$112 = 600.000 (Z-axis maximum rate, mm/min)

$120 = 93.750 (X-axis acceleration, mm/sec^2)

$121 = 93.750 (Y-axis acceleration, mm/sec^2)

$122 = 400.000 (Z-axis acceleration, mm/sec^2)

$130 = 760.000 (X-axis maximum travel, millimeters)

$131 = 600.000 (Y-axis maximum travel, millimeters)

$132 = 85.000 (Z-axis maximum travel, millimeters)

>>> $G

[GC:G0 G54 G17 G21 G90 G94 M5 M9 T0 F0.0 S0]

You can change the settings right in UGS.

How to set a macro for Z probe in Universal Gcode Sender

Here is my Macro setting in UGS:

Set Z

G20 G38.2 Z-.75 F2; G92 Z.057; G91 G0 Z.343

This will stop 0.4 inches from the surface.

For an inside corner plate you could use:

Set XY

G20 G38.2 X-1.50 F2; G92 X0.125; G91 G0 X0.875; G38.2 Y-1.50 F2; G92 Y0.125; G91 G0 Y0.875

Note: the G20 indicates inches, if you use MM use G21.

Say Alexa open browser.

Shoot I did not know what I was missing. I knew there was a button that said pendant in universal g code sender but I kind of assumed you had to buy a special piece of equipment for it. But no… you can use your cell phone or browser on you PC or Woo Hooo! I can use my HD8 Amazon tablet with Alexa.

You can do a lot with the pendant,.. jog, send files, reset to zero or use your macros.

I still have my PC connected directly to the CNC, I really would not suggest to run the machine wireless, but all the other stuff sure. My computer is on the other side of a wall so this makes it so much easier and faster to get a job done.

Reference to G Code Numbers

G00	Rapid positioning
G01	Linear interpolation
G02	Clockwise circular/helical interpolation
G03	Counterclockwise circular/helical interpolation
G04	Dwell
G10	Coordinate system origin setting
G17	XY Plane select
G18	XZ Plane select
G19	YZ Plane select
G20/G21	Inch/millimeter unit
G28	Return home
G28.1	Reference axes
G30	Return home
G38	Straight probe
G40	Cancel cutter radius compensation
G41/G42	Start cutter radius compensation left/right
G43	Apply tool length offset (plus)
G49	Cancel tool length offset
G50	Reset all scale factors to 1.0
G51	Set axis data input scale factors
G53	Move in absolute machine coordinate system
G54	Use fixture offset 1
G55	Use fixture offset 2
G56-58	Use fixture offset 3, 4, 5
G59	Use fixture offset 6/ use general fixture number
G61/G64	Exact stop/Constant Velocity mode
G73	Canned cycle – peck drilling
G80	Cancel motion mode (including canned cycles)
G81	Canned cycle – drilling
G82	Canned cycle – drilling with dwell
G83	Canned cycle – peck drilling
G85	Canned cycle – boring, no dwell, feed out
G86	Canned cycle – boring, spindle stop, rapid out
G88	Canned cycle – boring, spindle stop, manual out
G89	Canned cycle – boring, dwell, feed out
G90	Absolute distance mode
G91	Incremental distance mode
G92	Offset coordinates and set parameters
G92.x	Cancel G92 etc.
G93	Inverse time feed mode
G94	Feed per minute mode
G95	Feed per rev mode
G98	Initial level return after canned cycles
G99	R-point level return after canned cycles