2 of my Triple Z motors moving twice as far
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So, I originally started with a Vulcanus 40, but changed it several times. Now I have kind of a combination of BLV and a Ratrig CoreXY. I was having some problems with my bed and decided to eliminate the 4 pieces of 2020 and 4mm aluminum plate (about 5 lbs.) from the original Vulcanus design and change from 2 leadscrews with 4 linear rails to a Triple motor kinematic style. I also added a Duex5
I used my old config file and edited it for 3 Z motors. Now my rear single motor is moving correctly, but the right and left front motors are moving exactly twice the distance. Their are probably other issues in my file, but I want to get the Z axis working first.
Any assistance is appreciated.
Config.g
; Configuration file for Duet WiFi (firmware version 3)
; executed by the firmware on start-up
;
; generated by RepRapFirmware Configuration Tool v3.1.3 on Sun Jun 14 2020 23:31:14 GMT-0500 (Central Daylight Time); General preferences
G90 ; send absolute coordinates...
M83 ; ...but relative extruder moves
M550 P"The Plastic Beast" ; set printer name
M669 K1 ; select CoreXY mode; Network
M552 S1 ; enable network
M586 P0 S1 ; enable HTTP
M586 P1 S0 ; disable FTP
M586 P2 S0 ; disable Telnet; Drives
M569 P0 S0 ; physical drive 0 goes forwards
M569 P1 S0 ; physical drive 1 goes forwards
M569 P2 S0 ; Z front left physical drive 2 goes backwards
M569 P3 S1 ; physical drive 3 goes forwards
M569 P5 S0 ; Z front right physical drive 5 goes backwards
M569 P6 S0 ; Z middle rear physical drive 6 goes backwards
M584 X0 Y1 Z2:5:6 ; three Z motors connected to driver outputs 2, 5 and 6
M671 X-60:460:205 Y5:5:445 S0.5 ; leadscrews at front left, rear middle and front right
M350 Z16 E16 I0 ; configure microstepping without interpolation
M350 X16 Y16 I1 ; configure microstepping with interpolation
M92 X79.40 Y79.40 Z800.00 E399.40 ; set steps per mm
M566 X1000.00 Y1000.00 Z100.00 E120.00 ; set maximum instantaneous speed changes (mm/min)
M203 X24000.00 Y24000.00 Z300.00 E1200.00 ; set maximum speeds (mm/min)
M201 X3000.00 Y3000.00 Z100.00 E250.00 ; set accelerations (mm/s^2)
M906 X1400 Y1400 Z1400 E950 I30 ; set motor currents (mA) and motor idle factor in per cent
M84 S30 ; Set idle timeout; Axis Limits
M208 X0 Y0 Z0 S1 ; set axis minima
M208 X399 Y410 Z400 S0 ; set axis maxima; Endstops
M574 X1 S1 P"xstop" ; configure active-high endstop for low end on X via pin xstop
M574 Y1 S1 P"ystop" ; configure active-high endstop for low end on Y via pin ystop
M574 Z1 S2 ; configure Z-probe endstop for low end on Z; Z-Probe
M950 S0 C"duex.pwm1" ; create servo pin 0 for BLTouch
M558 P9 C"^zprobe.in" H5 F100 T4000 ; set Z probe type to bltouch and the dive height + speeds
G31 P500 X-26 Y1.7 Z1.135 ; set Z probe trigger value, offset and trigger height
M557 X5:372 Y7:405 S20 ; define mesh grid; Heaters
M308 S0 P"bedtemp" Y"thermistor" T100000 B3950 ; configure sensor 0 as thermistor on pin bedtemp
M950 H0 C"bedheat" T0 ; create bed heater output on bedheat and map it to sensor 0
M307 H0 B1 S1.00 ; enable bang-bang mode for the bed heater and set PWM limit
M140 H0 ; map heated bed to heater 0
M143 H0 S120 ; set temperature limit for heater 0 to 120C
M308 S1 P"e0temp" Y"thermistor" T100000 B4725 C7.06e-8 ; configure sensor 1 as thermistor on pin e0temp
M950 H1 C"e0heat" T1 ; create nozzle heater output on e0heat and map it to sensor 1
M307 H1 B0 S1.00 ; disable bang-bang mode for heater and set PWM limit
M143 H1 S285 ; set temperature limit for heater 1 to 285C; Fans
M950 F0 C"fan0" Q500 ; create fan 0 on pin fan0 and set its frequency
M106 P0 S0 H1 T45 ; set fan 0 value. Thermostatic control is turned on
M950 F1 C"fan1" Q500 ; create fan 1 on pin fan1 and set its frequency
M106 P1 S1 H1 T45 ; set fan 1 value. Thermostatic control is turned on; Tools
M563 P0 D0 H1 F0 ; define tool 0
G10 P0 X0 Y0 Z0 ; set tool 0 axis offsets
G10 P0 R0 S0 ; set initial tool 0 active and standby temperatures to 0C; Custom settings are not defined
; Miscellaneous
M575 P1 S1 B57600 ; enable support for PanelDue
M911 S10 R11 P"M913 X0 Y0 G91 M83 G1 Z3 E-5 F1000" ; set voltage thresholds and actions to run on power loss
M912 P0 S1 ; set cpu temp offset
M501
T0 : select first toolbed.g
; bed.g
; called to perform automatic bed compensation via G32
;
; generated by RepRapFirmware Configuration Tool v3.1.3 on Sun Jun 14 2020 23:31:14 GMT-0500 (Central Daylight Time)
M561 ; clear any bed transform
G28 ; home
G30 P0 X370 Y5 Z-99999 ; probe near left front leadscrew
G30 P1 X30 Y5 Z-99999 ; probe near right front leadscrew
G30 P2 X205 Y380 Z-99999 S3 ; probe near a rear middle leadscrew and calibrate 3 motors -
@cdsmith12 are the stepper motors the same e.g 1.8 or 0.9 deg per step?
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@moth4017
yes all three stepper motors are the same -
@cdsmith12 Are you 3 lead screws the same Pitch? turn each one manually 1 full turn and see if each corner moves the same amount.
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The config is correct and each motor driver will be getting the same steps. So the difference must come from a physical characteristic. Either the motors or the lead screws are not identical.
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That was it. I bought 2, then bought 2 more a couple years later. I thought they were the same since there wasn't any issues with the lead screw nuts. I'll order a new one with the right pitch
Thanks
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I take that back, about the coupler being the same. I had this thing all the way apart and all the pieces laying everywhere. I don't know how the heck I picked up the right coupler and leadscrew all those times and never had a mismatch until i just tried it.
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@cdsmith12 Be careful when talking about pitch with regard to lead screws. The important thing is "lead" which is how far a nut will travel in one revolution of the screw. With single start threads, the lead and the pitch happen to be the same. But many lead screws have multi start threads and the lead is the pitch multiplied by the number of thread starts. So for example 2mm pitch single start thread will have a lead of 2mm, but a 2mm pitch, 2 start thread will have a lead of 4mm and a 2mm pitch 4 start thread will have a lead of 8mm. If they were laid side by side, they would look very similar because the pitch is the same. So you have to look closely at the helix angle, or at the end of the screw to notice the difference. Oh and for the Z axis of a 3d printer, 2mm lead is the optimal for reasons which I will gladly explain if necessary.
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@deckingman Thank you and everyone for their input.
