I have two lasers running Smoothie that are having the same issues and i’m hoping someone could shed some light on the problem. Here is the gcode that is giving my lasers a hard time:
G0 X280 Y89 F7500
G1 X281.127200 Y89.204800 S0.000000
G1 X281.178000 Y89.204800 S0.400000
G1 X289.153600 Y89.204800 S0.000000
G0 X206.502000 Y89.255600 F15000
G1 X198.526400 Y89.255600 F15000
G1 X184.708800 Y89.255600 S0.400000
G1 X156.565600 Y89.255600 S0.000000
G0 X280 Y89 F7500
and here is the config I am running on the latest edge and master branch :
Basic motion configuration
default_feed_rate 8000 # Default speed (mm/minute) for G1/G2/G3 moves
default_seek_rate 8000 # Default speed (mm/minute) for G0 moves
mm_per_arc_segment 0.1 # Fixed length for line segments that divide arcs, 0 to disable
#mm_per_line_segment 5 # Cut lines into segments this size
mm_max_arc_error 0.01 # The maximum error for line segments that divide arcs 0 to disable
# note it is invalid for both the above be 0
# if both are used, will use largest segment length based on radius
Arm solution configuration : Cartesian robot. Translates mm positions into stepper positions
See
alpha_steps_per_mm 157.4802 # Steps per mm for alpha ( X ) stepper
beta_steps_per_mm 157.4802 # Steps per mm for beta ( Y ) stepper
gamma_steps_per_mm 159.5 # Steps per mm for gamma ( Z ) stepper
Planner module configuration : Look-ahead and acceleration configuration
See
acceleration 3000 # Acceleration in mm/second/second.
#z_acceleration 500 # Acceleration for Z only moves in mm/s^2, 0 uses acceleration which is the default. DO NOT SET ON A DELTA
junction_deviation 0.05 # See #junction-deviation
#z_junction_deviation 0.0 # For Z only moves, -1 uses junction_deviation, zero disables junction_deviation on z moves DO NOT SET ON A DELTA
Cartesian axis speed limits
x_axis_max_speed 30000 # Maximum speed in mm/min
y_axis_max_speed 8000 # Maximum speed in mm/min
z_axis_max_speed 300 # Maximum speed in mm/min
Stepper module configuration
Pins are defined as ports, and pin numbers, appending “!” to the number will invert a pin
See
alpha_step_pin 2.0 # Pin for alpha stepper step signal
alpha_dir_pin 0.5 # Pin for alpha stepper direction, add ‘!’ to reverse direction
alpha_en_pin 0.4 # Pin for alpha enable pin
alpha_current 0.6 # X stepper motor current
alpha_max_rate 30000.0 # Maximum rate in mm/min
beta_step_pin 2.1 # Pin for beta stepper step signal
beta_dir_pin 0.11 # Pin for beta stepper direction, add ‘!’ to reverse direction
beta_en_pin 0.10 # Pin for beta enable
beta_current 0.6 # Y stepper motor current
beta_max_rate 8000.0 # Maxmimum rate in mm/min
I think this might be a bug in Smoothieware because I can run all kinds of speed, acceleration, and jerk tests at higher speed without issue. This bit of gcode will cause the x axis to skip. If i turn down the acceleration and/or junction_deviation the problem only gets worse… but if i turn up the junction_deviation to .1 and the acceleration to 4000 the problem goes away. That’s counter intuitive. Turning up the acceleration makes all my arc wavy and zig-zagy… so not a great workaround.
Any help would be greatly welcome. also if someone could reproduce the issue that would help prove it’s not mechanical problem. I have a K40 and a converted Full Spectrum laser cutter both running Smoothie with the issue and I have done all of the belt, wheels etc adjustments I can think of.