Egg bot

Setup of my egg bot

Technical data:

  • My motor driver can only run a half step mode which is too coarse for the rotation axis
  • X is the rotation axis, scaled to 360 units / turn.
    Stepper motor = 200 steps/turn = 400 half-steps / turn
    $100 = 400 / 360 = 1.111
  • Y is the axis with the pen holder with a range of 110°
    Driven by a worm gear 1/50
    $101 = 50 * 400 / 360 = 55.555

Example object is a table tennis ball.
Attention: when using an egg, be sure to lift and lower the pen enough - the elipse form of the egg is tricky.

https://github.com/evil-mad/EggBot/blob/master/example%20files/General/worldmap.svg

Example patterns can be found on github repository for software to drive The original EggBot, by Evil Mad Scientist Laboratories: https://github.com/evil-mad/EggBot/tree/master/example%20files

Find the settings, used here, at the end of this page:


Related video:

 

 

 

 

 

 

 

 

 

 

 

 


Source comes from https://github.com/cprezzi/grbl-servo, needs to be compiled via Arduino-IDE. Uploadable hex-file 'grbl_v1.1f_Servo.hex' is included in GRBL-Plotter zip file. This is a special version with servo support (switchable in config.h)

  • The PWM frequency is set to 61Hz (prescaler 1/1024).
  • The pulse width range is 0.5 - 2.5ms.
  • S0 does not deactivate the PWM, but instead send min pulse width.
  • Set the max. S-value to $30=255 to get a S-value range of 0-255.
  • You should have a M3S0 at the start of your gcode to activate the servo and M5 at end to deactivate it.

 


Setup values can be applied via copy & paste on the Serial-COM window of GRBL-Plotter.
$0=10          (Sets time length per step. Minimum 3usec.)
$1=25          (Sets a short hold delay when stopping to let dynamics settle before disabling steppers. Value 255 keeps motors enabled with no delay.)
$2=0           (Inverts the step signal. Set axis bit to invert (00000ZYX).)
$3=0           (Inverts the direction signal. Set axis bit to invert (00000ZYX).)
$4=0           (Inverts the stepper driver enable pin signal.)
$5=0           (Inverts the all of the limit input pins.)
$6=0           (Inverts the probe input pin signal.)
$10=1          (Alters data included in status reports.)
$11=0.010      (Sets how fast Grbl travels through consecutive motions. Lower value slows it down.)
$12=0.002      (Sets the G2 and G3 arc tracing accuracy based on radial error. Beware: A very small value may effect performance.)
$13=0          (Enables inch units when returning any position and rate value that is not a settings value.)
$20=0          (Enables soft limits checks within machine travel and sets alarm when exceeded. Requires homing.)
$21=0          (Enables hard limits. Immediately halts motion and throws an alarm when switch is triggered.)
$22=0          (Enables homing cycle. Requires limit switches on all axes.)
$23=0          (Homing searches for a switch in the positive direction. Set axis bit (00000ZYX) to search in negative direction.)
$24=25.000     (Feed rate to slowly engage limit switch to determine its location accurately.)
$25=500.000    (Seek rate to quickly find the limit switch before the slower locating phase.)
$26=250        (Sets a short delay between phases of homing cycle to let a switch debounce.)
$27=1.000      (Retract distance after triggering switch to disengage it. Homing will fail if switch isn't cleared.)
$30=1000       (Maximum spindle speed. Sets PWM to 100% duty cycle.)
$31=0          (Minimum spindle speed. Sets PWM to 0.4% or lowest duty cycle.)
$32=0          (Enables laser mode. Consecutive G1/2/3 commands will not halt when spindle speed is changed.)
$100=1.111     (X-axis travel resolution in steps per millimeter.)
$101=55.556    (Y-axis travel resolution in steps per millimeter.)
$102=250.000   (Z-axis travel resolution in steps per millimeter.)
$110=10000.000   (X-axis maximum rate. Used as G0 rapid rate.)
$111=600.000   (Y-axis maximum rate. Used as G0 rapid rate.)
$112=500.000   (Z-axis maximum rate. Used as G0 rapid rate.)
$120=500.000   (X-axis acceleration. Used for motion planning to not exceed motor torque and lose steps.)
$121=500.000   (Y-axis acceleration. Used for motion planning to not exceed motor torque and lose steps.)
$122=10.000    (Z-axis acceleration. Used for motion planning to not exceed motor torque and lose steps.)
$130=200.000   (Maximum X-axis travel distance from homing switch. Determines valid machine space for soft-limits and homing search distances.)
$131=200.000   (Maximum Y-axis travel distance from homing switch. Determines valid machine space for soft-limits and homing search distances.)
$132=200.000   (Maximum Z-axis travel distance from homing switch. Determines valid machine space for soft-limits and homing search distances.)

 


GRBL-Plotter Settings:

For quick success when setting up GRBL-Plotter for this application, this INI file can be used (e.g. by drag & drop).

Note: This INI files includes custom-button settings and color-scheme, which will overwrite the current settings.

Egg Bot INI File for RC Servo Note: a different grbl version is needed!

 

We use our own or third party cookies to improve your web browsing experience. If you continue to browse we consider that you accept their use.  Accept  More information