Zero Backoff occasionally not working

mabel Mar 27, 2013 #

When homing with the x-axis, it occasionally does not do the movement for Zero Backoff. It backs off the latch until it opens and then goes on to homing the y-axis without moving the zero backoff distance. I went through the homing sequence 20 times, and 3 of those times it did not do the Zero Backoff. I am going to continue to test it and try to get it working, but I wanted to know if you had any ideas as well. Below is a copy of the x-axis settings.

Thank you!

[xam] x axis mode 1 [standard]

[xvm] x velocity maximum 50.000 mm/min

[xfr] x feedrate maximum 600.000 mm/min

[xtm] x travel maximum 150.000 mm

[xjm] x jerk maximum 20000000 mm/min^3

[xjh] x jerk homing 20000000 mm/min^3

[xjd] x junction deviation 0.0500 mm (larger is faster)

[xsn] x switch min 3 [0=off,1=homing,2=limit,3=limit+homing]

[xsx] x switch max 2 [0=off,1=homing,2=limit,3=limit+homing]

[xsv] x search velocity 150.000 mm/min

[xlv] x latch velocity 150.000 mm/min

[xlb] x latch backoff 5.000 mm

[xzb] x zero backoff 5.000 mm

RileyStaff Apr 2, 2013 #

Can you post the results of a $$ command and also hit reset and give us the build / version number info.

Thanks,

Riley

mabel Apr 10, 2013 #

Here are the results of a $$ command. It gave the build and version number first as build 370.08 and version 0.95.

[fb] firmware build 370.08
[fv] firmware version 0.95
[hv] hardware version 7.00
[id] TinyG ID 9H3906-SQE
[ja] junction acceleration 100000 mm
[ct] chordal tolerance 0.010 mm
[st] switch type 0 [0=NO,1=NC]
[ej] enable json mode 0 [0=text,1=JSON]
[jv] json verbosity 4 [0=silent,1=footer,2=messages,3=configs,4=linenum,5=verbose]
[tv] text verbosity 1 [0=silent,1=verbose]
[qv] queue report verbosity 0 [0=off,1=filtered,2=verbose]
[sv] status report verbosity 2 [0=off,1=filtered,2=verbose]
[si] status interval 100 ms
[ic] ignore CR or LF on RX 0 [0=off,1=CR,2=LF]
[ec] expand LF to CRLF on TX 0 [0=off,1=on]
[ee] enable echo 0 [0=off,1=on]
[ex] enable xon xoff 1 [0=off,1=on]
[baud] USB baud rate 5 [1=9600,2=19200,3=38400,4=57600,5=115200,6=230400]
[gpl] default gcode plane 0 [0=G17,1=G18,2=G19]
[gun] default gcode units mode 1 [0=G20,1=G21]
[gco] default gcode coord system 1 [1-6 (G54-G59)]
[gpa] default gcode path control 2 [0=G61,1=G61.1,2=G64]
[gdi] default gcode distance mode 0 [0=G90,1=G91]
[1ma] m1 map to axis 0 [0=X,1=Y,2=Z...]
[1sa] m1 step angle 1.800 deg
[1tr] m1 travel per revolution 20.290 mm
[1mi] m1 microsteps 8 [1,2,4,8]
[1po] m1 polarity 1 [0=normal,1=reverse]
[1pm] m1 power management 1 [0=off,1=on]
[2ma] m2 map to axis 1 [0=X,1=Y,2=Z...]
[2sa] m2 step angle 1.800 deg
[2tr] m2 travel per revolution 20.290 mm
[2mi] m2 microsteps 8 [1,2,4,8]
[2po] m2 polarity 1 [0=normal,1=reverse]
[2pm] m2 power management 1 [0=off,1=on]
[3ma] m3 map to axis 2 [0=X,1=Y,2=Z...]
[3sa] m3 step angle 7.500 deg
[3tr] m3 travel per revolution 0.044 mm
[3mi] m3 microsteps 8 [1,2,4,8]
[3po] m3 polarity 1 [0=normal,1=reverse]
[3pm] m3 power management 1 [0=off,1=on]
[4ma] m4 map to axis 3 [0=X,1=Y,2=Z...]
[4sa] m4 step angle 1.800 deg
[4tr] m4 travel per revolution 360.000 mm
[4mi] m4 microsteps 8 [1,2,4,8]
[4po] m4 polarity 0 [0=normal,1=reverse]
[4pm] m4 power management 1 [0=off,1=on]
[xam] x axis mode 1 [standard]
[xvm] x velocity maximum 50.000 mm/min
[xfr] x feedrate maximum 600.000 mm/min
[xtm] x travel maximum 150.000 mm
[xjm] x jerk maximum 20000000 mm/min^3
[xjh] x jerk homing 20000000 mm/min^3
[xjd] x junction deviation 0.0500 mm (larger is faster)
[xsn] x switch min 3 [0=off,1=homing,2=limit,3=limit+homing]
[xsx] x switch max 2 [0=off,1=homing,2=limit,3=limit+homing]
[xsv] x search velocity 150.000 mm/min
[xlv] x latch velocity 150.000 mm/min
[xlb] x latch backoff 5.000 mm
[xzb] x zero backoff 5.000 mm
[yam] y axis mode 1 [standard]
[yvm] y velocity maximum 200.000 mm/min
[yfr] y feedrate maximum 600.000 mm/min
[ytm] y travel maximum 150.000 mm
[yjm] y jerk maximum 20000000 mm/min^3
[yjh] y jerk homing 20000000 mm/min^3
[yjd] y junction deviation 0.0500 mm (larger is faster)
[ysn] y switch min 3 [0=off,1=homing,2=limit,3=limit+homing]
[ysx] y switch max 2 [0=off,1=homing,2=limit,3=limit+homing]
[ysv] y search velocity 50.000 mm/min
[ylv] y latch velocity 50.000 mm/min
[ylb] y latch backoff 5.000 mm
[yzb] y zero backoff 10.000 mm
[zam] z axis mode 1 [standard]
[zvm] z velocity maximum 40.000 mm/min
[zfr] z feedrate maximum 500.000 mm/min
[ztm] z travel maximum 75.000 mm
[zjm] z jerk maximum 200000 mm/min^3
[zjh] z jerk homing 200000 mm/min^3
[zjd] z junction deviation 0.0500 mm (larger is faster)
[zsn] z switch min 3 [0=off,1=homing,2=limit,3=limit+homing]
[zsx] z switch max 2 [0=off,1=homing,2=limit,3=limit+homing]
[zsv] z search velocity 40.000 mm/min
[zlv] z latch velocity 40.000 mm/min
[zlb] z latch backoff 2.000 mm
[zzb] z zero backoff 3.000 mm
[aam] a axis mode 1 [standard]
[avm] a velocity maximum 3600.000 deg/min
[afr] a feedrate maximum 3600.000 deg/min
[atm] a travel maximum -1.000 deg
[ajm] a jerk maximum 20000000 deg/min^3
[ajh] a jerk homing 20000000 mm/min^3
[ajd] a junction deviation 0.0500 deg (larger is faster)
[ara] a radius value 1.0000 deg
[asn] a switch min 0 [0=off,1=homing,2=limit,3=limit+homing]
[asx] a switch max 0 [0=off,1=homing,2=limit,3=limit+homing]
[asv] a search velocity 600.000 deg/min
[alv] a latch velocity 100.000 deg/min
[alb] a latch backoff 10.000 deg
[azb] a zero backoff 2.000 deg
[bam] b axis mode 0 [disabled]
[bvm] b velocity maximum 3600.000 deg/min
[bfr] b feedrate maximum 3600.000 deg/min
[btm] b travel maximum -1.000 deg
[bjm] b jerk maximum 20000000 deg/min^3
[bjd] b junction deviation 0.0500 deg (larger is faster)
[bra] b radius value 1.0000 deg
[cam] c axis mode 0 [disabled]
[cvm] c velocity maximum 3600.000 deg/min
[cfr] c feedrate maximum 3600.000 deg/min
[ctm] c travel maximum -1.000 deg
[cjm] c jerk maximum 20000000 deg/min^3
[cjd] c junction deviation 0.0500 deg (larger is faster)
[cra] c radius value 1.0000 deg
[p1frq] pwm frequency 0.000 Hz
[p1csl] pwm cw speed lo 0.000 RPM
[p1csh] pwm cw speed hi 0.000 RPM
[p1cpl] pwm cw phase lo 0.000 [0..1]
[p1cph] pwm cw phase hi 0.000 [0..1]
[p1wsl] pwm ccw speed lo 0.000 RPM
[p1wsh] pwm ccw speed hi 0.000 RPM
[p1wpl] pwm ccw phase lo 0.000 [0..1]
[p1wph] pwm ccw phase hi 0.000 [0..1]
[p1pof] pwm phase off 0.000 [0..1]
[g54x] g54 x offset 0.000 mm
[g54y] g54 y offset 0.000 mm
[g54z] g54 z offset 0.000 mm
[g54a] g54 a offset 0.000 deg
[g54b] g54 b offset 0.000 deg
[g54c] g54 c offset 0.000 deg
[g55x] g55 x offset 75.000 mm
[g55y] g55 y offset 75.000 mm
[g55z] g55 z offset 0.000 mm
[g55a] g55 a offset 0.000 deg
[g55b] g55 b offset 0.000 deg
[g55c] g55 c offset 0.000 deg
[g56x] g56 x offset 0.000 mm
[g56y] g56 y offset 0.000 mm
[g56z] g56 z offset 0.000 mm
[g56a] g56 a offset 0.000 deg
[g56b] g56 b offset 0.000 deg
[g56c] g56 c offset 0.000 deg
[g57x] g57 x offset 0.000 mm
[g57y] g57 y offset 0.000 mm
[g57z] g57 z offset 0.000 mm
[g57a] g57 a offset 0.000 deg
[g57b] g57 b offset 0.000 deg
[g57c] g57 c offset 0.000 deg
[g58x] g58 x offset 0.000 mm
[g58y] g58 y offset 0.000 mm
[g58z] g58 z offset 0.000 mm
[g58a] g58 a offset 0.000 deg
[g58b] g58 b offset 0.000 deg
[g58c] g58 c offset 0.000 deg
[g59x] g59 x offset 0.000 mm
[g59y] g59 y offset 0.000 mm
[g59z] g59 z offset 0.000 mm
[g59a] g59 a offset 0.000 deg
[g59b] g59 b offset 0.000 deg
[g59c] g59 c offset 0.000 deg
[g92x] g92 x offset 0.000 mm
[g92y] g92 y offset 0.000 mm
[g92z] g92 z offset 0.000 mm
[g92a] g92 a offset 0.000 deg
[g92b] g92 b offset 0.000 deg
[g92c] g92 c offset 0.000 deg
[g28x] g28 x location 0.000 mm
[g28y] g28 y location 0.000 mm
[g28z] g28 z location 0.000 mm
[g28a] g28 a location 0.000 deg
[g28b] g28 b location 0.000 deg
[g28c] g28 c location 0.000 deg
[g30x] g30 x location 0.000 mm
[g30y] g30 y location 0.000 mm
[g30z] g30 z location 0.000 mm
[g30a] g30 a location 0.000 deg
[g30b] g30 b location 0.000 deg
[g30c] g30 c location 0.000 deg

aldenStaff Apr 10, 2013 #

I have a suspicion of what's going on here. I suspect that the latch operation takes the switch to a point where it's right on the edge of firing. Then the backoff fires the switch again and ends the backoff. I think it's worth an experiment to lock out switch detection during the backoff and see if that doesn;t prevent this. I'll add it to my list, or you can hack the code in cycle_homing.c if you want to experiment yourself.