Sainsmart RYC GRBL V2 Upgrade

May 3, 2019

Huy Le

3 minute read

PROJECT LAYOUT

GRBL has been optimized for Ardunio’s ATmega328p. So most configurations out there will use the Arduino Uno and a CNC shield. I decide to go with the Sainsmart RYC-GRBL-V2 hoping it would work out of the box.

The reason why this is a long post is because it didn’t work out of the box.

To get it up and running these are the list of things I changed to get it working.

Adjusted stepper current
Adjusted stepper speed to keep it from skipping
Setup limits to X and Y axis
Changed GRBL firmware to set negative home, after zeroed
Negative Homing
- https://github.com/grbl/grbl/wiki/Frequently-Asked-Questions#why-is-grbl-in-all-negative-coordinates-after-homing-or-it-so-annoying-and-not-what-im-used-to
  - had to set a var in the config.h file and recompiled
  - HOMING_FORCE_SET_ORIGIN uncommented out in code, allow for machine to zero, zero when homed
    - this is not default, because of the legacy of CNC machines. GRBL wanted to keep it consistent
Set “Min” spindle speed to get corners to cut through
Weak power control
Homing Switches
- Had to invert $5
Motor speed - in mm/min not mm/s
- setting the motors speed limit on Lightburn, watch for mm/min vs mm/s
Change laser enable pin to Z+ (limit switch in code)
- change in source to take on the Z+ as the pin
Min “Spindle” speed - 25 - allow to cut through corners
- or else, the corners wont be cuts
  - ideally, we want to to set this value to be minimum as possible to reduce burn in the corners
Weak power control
- S-power setting in Lightburn gets changed to 2000, twice that of the $30 value in GRBL of 1000
  - This 2000 is doubled of the 1000 value, which is the limit set in the config.h file

NOTES: #

About the firmware GRBL 1.1 #

Laser Mode
- https://github.com/gnea/grbl/wiki/Grbl-v1.1-Laser-Mode
  - enabling it will require you to send Grbl $32=1 command

Good overall tutorial here #

http://www.oak600.com/2018/03/19/upgrading-a-k40-laser-cutter-part-1-control-board-upgrade/ Has all the settings..

need to enable laser pin #

inverting the pwm signal with hardware https://github.com/gnea/grbl/issues/22

Flashing #

use Arduino IDE, and UNO board (indeed has a ATmega328p)
- success from user in Amazon review

Worked on #

Negative Homing
- https://github.com/grbl/grbl/wiki/Frequently-Asked-Questions#why-is-grbl-in-all-negative-coordinates-after-homing-or-it-so-annoying-and-not-what-im-used-to
- had to set a var in the config.h file and recompiled
- HOMING_FORCE_SET_ORIGIN uncommented out in code, allow for machine to zero, zero when homed
  - this is not default, because of the legacy of CNC machines. GRBL wanted to keep it consistent
Homing Switches
- Had to invert $5
Motor speed - in mm/min not mm/s
- setting the motors speed limit on Lightburn, watch for mm/min vs mm/s
Change laser enable pin to Z+ (limit switch in code)
- change in source to take on the Z+ as the pin
Min “Spindle” speed - 25 - allow to cut through corners
- or else, the corners wont be cuts
- ideally, we want to to set this value to be minimum as possible to reduce burn in the corners
Weak power control
- S-power setting in Lightburn gets changed to 2000, twice that of the $30 value in GRBL of 1000
- This 2000 is doubled of the 1000 value, which is the limit set in the config.h file

FINAL CONFIGURATION #

  $0=10
  $1=25
  $2=0
  $3=2
  $4=0
  $5=1
  $6=0
  $10=1
  $11=0.010
  $12=0.002
  $13=0
  $20=0
  $21=1
  $22=1
  $23=3
  $24=25.000
  $25=1000.000
  $26=250
  $27=1.000
  $30=1000
  $31=50
  $32=1
  $100=158.000
  $101=158.000
  $102=158.000
  $110=3000.000
  $111=3000.000
  $112=3000.000
  $120=300.000
  $121=300.000
  $122=200.000
  $130=300.000
  $131=200.000
  $132=200.000