Z Axis again

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  • April 3, 2018 at 7:29 pm #10944
    dustin davis
    Member

    So here I am trying to cut a 2.5d sign. My machine cuts good when plunging the z axis. This project has the z axis moving as the X axis moving in a raster cut. The Z keeps changing the zero position. The Z zero moves up by .125 – .200 inches. I have to reset the machine and restart the cut, but the Z axis keeps moving. I am not sure that I have my TinyG configured correctly. I have 8mm leadscrews on all my axis, but I had to set the travel much higher than the actual measurement. My Z Axis travel is set at 1.27”, but the actual revolution travel is .316”. I will try to post my setting if I can figure out how to capture it.

    April 3, 2018 at 9:13 pm #10945
    cmcgrath5035
    Moderator

    The $$ command will list your parameters in a console window.

    What do you use to interface to tinyG and send Gcode?
    Chilipeppr, CoolTerm, cnc.js, etc
    Running Windows, Mac, Linux, ?
    That will help us suggest additional debug strategies.

    April 3, 2018 at 9:27 pm #10946
    dustin davis
    Member

    I have used Chilipepper and CNC.Js, both are getting the same result of the Z axis moving the zero point higher. If I stop the machine over the top of in cut material place the Z back at zero the end mill is above the surface. It started touching.

    Windows 7 HP Pavilion DV7 laptop

    If there is a way to capture the TinyG parameters from Windows 7 I will post those so you can see them. Otherwise I will have to type them into a post. I can do that tomorrow afternoon.

    April 4, 2018 at 7:08 pm #10947
    dustin davis
    Member

    [fb] firmware build 440.20
    [fv] firmware version 0.97
    [hp] hardware platform 1.00
    [hv] hardware version 8.00
    [id] TinyG ID 5X3848-VDS
    [ja] junction acceleration 50000 in
    [ct] chordal tolerance 0.0004 in
    [sl] soft limit enable 0
    [st] switch type 1 [0=NO,1=NC]
    [mt] motor idle timeout 2.00 Sec
    [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]
    [js] json serialize style 1 [0=relaxed,1=strict]
    [tv] text verbosity 1 [0=silent,1=verbose]
    [qv] queue report verbosity 1 [0=off,1=single,2=triple]
    [sv] status report verbosity 1 [0=off,1=filtered,2=verbose]
    [si] status interval 250 ms
    [ec] expand LF to CRLF on TX 0 [0=off,1=on]
    [ee] enable echo 0 [0=off,1=on]
    [ex] enable flow control 1 [0=off,1=XON/XOFF, 2=RTS/CTS]
    [baud] USB baud rate 5 [1=9600,2=19200,3=38400,4=57600,5=115200,6=230400]
    [net] network mode 0 [0=master]
    [gpl] default gcode plane 0 [0=G17,1=G18,2=G19]
    [gun] default gcode units mode 0 [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 1 [0=X,1=Y,2=Z…]
    [1sa] m1 step angle 1.800 deg
    [1tr] m1 travel per revolution 0.2950 in
    [1mi] m1 microsteps 8 [1,2,4,8]
    [1po] m1 polarity 1 [0=normal,1=reverse]
    [1pm] m1 power management 2 [0=disabled,1=always on,2=in cycle,3=when moving]
    [2ma] m2 map to axis 1 [0=X,1=Y,2=Z…]
    [2sa] m2 step angle 1.800 deg
    [2tr] m2 travel per revolution 0.2950 in
    [2mi] m2 microsteps 8 [1,2,4,8]
    [2po] m2 polarity 1 [0=normal,1=reverse]
    [2pm] m2 power management 2 [0=disabled,1=always on,2=in cycle,3=when moving]
    [3ma] m3 map to axis 0 [0=X,1=Y,2=Z…]
    [3sa] m3 step angle 1.800 deg
    [3tr] m3 travel per revolution 0.3140 in
    [3mi] m3 microsteps 8 [1,2,4,8]
    [3po] m3 polarity 1 [0=normal,1=reverse]
    [3pm] m3 power management 2 [0=disabled,1=always on,2=in cycle,3=when moving]
    [4ma] m4 map to axis 2 [0=X,1=Y,2=Z…]
    [4sa] m4 step angle 1.800 deg
    [4tr] m4 travel per revolution 1.2700 in
    [4mi] m4 microsteps 8 [1,2,4,8]
    [4po] m4 polarity 0 [0=normal,1=reverse]
    [4pm] m4 power management 3 [0=disabled,1=always on,2=in cycle,3=when moving]
    [xam] x axis mode 1 [standard]
    [xvm] x velocity maximum 150 in/min
    [xfr] x feedrate maximum 100 in/min
    [xtn] x travel minimum 0.000 in
    [xtm] x travel maximum -20.000 in
    [xjm] x jerk maximum 25 in/min^3 * 1 million
    [xjh] x jerk homing 25 in/min^3 * 1 million
    [xjd] x junction deviation 0.0020 in (larger is faster)
    [xsn] x switch min 0 [0=off,1=homing,2=limit,3=limit+homing]
    [xsx] x switch max 0 [0=off,1=homing,2=limit,3=limit+homing]
    [xsv] x search velocity 20 in/min
    [xlv] x latch velocity 4 in/min
    [xlb] x latch backoff 0.197 in
    [xzb] x zero backoff 0.039 in
    [yam] y axis mode 1 [standard]
    [yvm] y velocity maximum 150 in/min
    [yfr] y feedrate maximum 100 in/min
    [ytn] y travel minimum 0.000 in
    [ytm] y travel maximum -20.000 in
    [yjm] y jerk maximum 25 in/min^3 * 1 million
    [yjh] y jerk homing 25 in/min^3 * 1 million
    [yjd] y junction deviation 0.0020 in (larger is faster)
    [ysn] y switch min 0 [0=off,1=homing,2=limit,3=limit+homing]
    [ysx] y switch max 0 [0=off,1=homing,2=limit,3=limit+homing]
    [ysv] y search velocity 20 in/min
    [ylv] y latch velocity 4 in/min
    [ylb] y latch backoff 0.197 in
    [yzb] y zero backoff 0.039 in
    [zam] z axis mode 1 [standard]
    [zvm] z velocity maximum 31 in/min
    [zfr] z feedrate maximum 31 in/min
    [ztn] z travel minimum -3.000 in
    [ztm] z travel maximum 3.000 in
    [zjm] z jerk maximum 25 in/min^3 * 1 million
    [zjh] z jerk homing 25 in/min^3 * 1 million
    [zjd] z junction deviation 0.0200 in (larger is faster)
    [zsn] z switch min 0 [0=off,1=homing,2=limit,3=limit+homing]
    [zsx] z switch max 0 [0=off,1=homing,2=limit,3=limit+homing]
    [zsv] z search velocity 5 in/min
    [zlv] z latch velocity 4 in/min
    [zlb] z latch backoff 0.197 in
    [zzb] z zero backoff 0.125 in
    [aam] a axis mode 0 [disabled]
    [avm] a velocity maximum 230400 deg/min
    [afr] a feedrate maximum 230400 deg/min
    [atn] a travel minimum 0.000 deg
    [atm] a travel maximum -1.000 deg
    [ajm] a jerk maximum 218059 deg/min^3 * 1 million
    [ajh] a jerk homing 286461 deg/min^3 * 1 million
    [ajd] a junction deviation 0.0500 deg (larger is faster)
    [ara] a radius value 0.0000 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 deg/min
    [alv] a latch velocity 100 deg/min
    [alb] a latch backoff 5.000 deg
    [azb] a zero backoff 2.000 deg
    [bam] b axis mode 0 [disabled]
    [bvm] b velocity maximum 3600 deg/min
    [bfr] b feedrate maximum 3600 deg/min
    [btn] b travel minimum -1.000 deg
    [btm] b travel maximum -1.000 deg
    [bjm] b jerk maximum 20 deg/min^3 * 1 million
    [bjd] b junction deviation 0.0500 deg (larger is faster)
    [bra] b radius value 0.0394 deg
    [cam] c axis mode 0 [disabled]
    [cvm] c velocity maximum 3600 deg/min
    [cfr] c feedrate maximum 3600 deg/min
    [ctn] c travel minimum -1.000 deg
    [ctm] c travel maximum -1.000 deg
    [cjm] c jerk maximum 20 deg/min^3 * 1 million
    [cjd] c junction deviation 0.0500 deg (larger is faster)
    [cra] c radius value 0.0394 deg
    [p1frq] pwm frequency 2500 Hz
    [p1csl] pwm cw speed lo 500 RPM
    [p1csh] pwm cw speed hi 12000 RPM
    [p1cpl] pwm cw phase lo 0.125 [0..1]
    [p1cph] pwm cw phase hi 100.000 [0..1]
    [p1wsl] pwm ccw speed lo 1000 RPM
    [p1wsh] pwm ccw speed hi 2000 RPM
    [p1wpl] pwm ccw phase lo 0.125 [0..1]
    [p1wph] pwm ccw phase hi 0.200 [0..1]
    [p1pof] pwm phase off 0.100 [0..1]
    [g54x] g54 x offset 0.000 in
    [g54y] g54 y offset 0.000 in
    [g54z] g54 z offset 0.000 in
    [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 2.953 in
    [g55y] g55 y offset 2.953 in
    [g55z] g55 z offset 0.000 in
    [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 in
    [g56y] g56 y offset 0.000 in
    [g56z] g56 z offset 0.000 in
    [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 in
    [g57y] g57 y offset 0.000 in
    [g57z] g57 z offset 0.000 in
    [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 in
    [g58y] g58 y offset 0.000 in
    [g58z] g58 z offset 0.000 in
    [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 in
    [g59y] g59 y offset 0.000 in
    [g59z] g59 z offset 0.000 in
    [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 in
    [g92y] g92 y offset 0.000 in
    [g92z] g92 z offset 0.000 in
    [g92a] g92 a offset 0.000 deg
    [g92b] g92 b offset 0.000 deg
    [g92c] g92 c offset 0.000 deg
    [g28x] g28 x position 0.000 in
    [g28y] g28 y position 0.000 in
    [g28z] g28 z position 0.000 in
    [g28a] g28 a position 0.000 deg
    [g28b] g28 b position 0.000 deg
    [g28c] g28 c position 0.000 deg
    [g30x] g30 x position 0.000 in
    [g30y] g30 y position 0.000 in
    [g30z] g30 z position 0.000 in
    [g30a] g30 a position 0.000 deg
    [g30b] g30 b position 0.000 deg
    [g30c] g30 c position 0.000 deg
    tinyg [inch] ok>
    tinyg [inch] ok>

    April 4, 2018 at 7:14 pm #10948
    dustin davis
    Member

    I have nema 23 187oz 1.8 2.5A motors on all axis. I am using 2 on the Y, 1 on X and 1 on Z. My power supply is a 24VDC I want to say 350W. I have 8mm leadscrews on all axis. It’s not overheating, my garage has been in the 40’s all week. It’s 37 right now. I am running a HP laptop probably 2007 model with Windows 7. I have tried to run the gcode with Chilipepper and CNCJs results are the same. I saw a forum post somewhere that was talking about the junction deviation causing this, but I am not exactly sure what to try at this point. Thanks for any help.

    April 5, 2018 at 6:41 am #10949
    cmcgrath5035
    Moderator

    A typical value of $xjd is 0.01mm for legacy ShapeOko machines, that translates to $xjd = 0.01/25.4 = 0.0004in (approx). Your values are much larger (therefor faster), but not necessarily a problem.

    Think of it this way – you want your machine to mill a straight line in the X direction for a bit, then make a 90 degree turn and mill straight in Y direction. To manage the required deceleration of the mass of your spindle in the X direction, TinyG will begin slowing the X Velocity before the spindle reached the 90 degree turn because the spindle cannot be instantaneously stopped and restarted in a different direction.
    A larger $xjd (or $yjd) says “it’s OK to start accelerating Y when the spindle gets close to the junction”, thus causing your 90 degree turn to become an arc. A larger $xjd value says that you accept more imprecision in these corners in order to keep you machine in manageable motion, thus reducing the overall time for your job to run.
    That is what motion control is all about.

    I’ll suspect your Z zero creep is a result of your $_pm=3 setting, you should try $_pm=2, in-cycle. In-cycle says that motor is energized when any axis is moving. You need to keep Z energized to provide holding torque for the spindle as you move X and Y around, so $4pm=2. I’ll guess that X,Y motion is pushing the spindle up (away from) the work surface due to lack of holding torque.
    $_pm=3 is really only useful when you have a machine that has no holding torque demands on axes that are not moving.

    As for $4tr=1.27in when other identical leadscrews are =0.3, that is just strange, implies that Z motor driver is sending step pulses approx 4 times as often as it should be. Could be wiring (but doubtful), could be corrupted internal parameter, could be a driver defect or short on the board. For example, You have $4mi=8, but if the driver device is stuck at mi=2, tinyG fw would be calling for 4 times as many steps as would be required. Try setting $4mi=2 and see what value of $4tr is required.

    Make the $_pm change first to see if that corrects behavior

    April 5, 2018 at 3:32 pm #10950
    dustin davis
    Member

    CMCGRATH5035 I tried all your suggestions and one of them I think is right on. My Z axis is very grainy sounding. So I switched the Z axis driver motor 4 with the X axis and the X axis is very grainy now. It is not a smooth motor sound like the other drivers. Maybe that Driver is bad. I only recently changed my machine to use 4 motors rather than the 3 I had built it with. So I never used the 4th motor driver. Even adjusting the amps on the driver only makes it quiet when it is so low the motor is not turning. Maybe I just got a bad board. I only had it sense last August and haven’t really had time to play with it very much.

    April 5, 2018 at 5:31 pm #10953
    cmcgrath5035
    Moderator

    Try this
    1. Connect to tinyG(logically)
    2. From the console, enter G21 to switch to mm mode
    3. Run $$ command and copy/paste the resulting parameters list to a file for reference(in mm mode).
    4. From Command interface, enter defa=1 followed by carriage return
    This will reset all tinyG parameters, including hidden ones, to a factory default set.
    5. Reconnect to tinyG, stay in mm mode.
    6. Re-enter your parameters, in mm,from the file you made, one at a time, via the Command Line

    Retry your motion tests.

    April 14, 2018 at 10:02 am #10964
    dustin davis
    Member

    OK I fixed my issue. I ordered a new board and the machine is running perfect. I am assuming the motor 4 driver went bad somehow. My Z axis was missing steps and running erratic so I changed the z to motor 3 and x to motor 4. The x started acting erratic. That is what led me to replacing the board.

    April 15, 2018 at 6:06 pm #10965
    cmcgrath5035
    Moderator

    Yes, swapping the logical connects is probably the quickest and easiest way to test that sort of behavior.

    Good luck from here

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