Retract problem (Flex3Drive)

vapvap

After installing the "Flex3Drive" extruder (on delta), I cannot set up the retract. Printing occurs with strong under-extrusion. When I printing with an increase in the length of the retraction, the sound of the "stalling motor" increases.
Please tell me where my mistake could be?

P.S. The installation of the extruder was done strictly according to the instructions from the official website.

video_2020-12-24_13-37-27.mp4

Carlo

@vapvap
Can you post your config I have the flex3 working flawless may be able to help also what motor are you using ?

dc42

Try reducing the extruder acceleration setting in the M201 command.

vapvap

@Carlo

; Configuration file for Duet WiFi (firmware version 1.21)
; executed by the firmware on start-up
;
; generated by RepRapFirmware Configuration Tool on Mon Aug 06 2018 00:13:45 GMT+0100 (IST)

; General preferences
G90 ; Send absolute coordinates...
M83 ; ...but relative extruder moves
M555 P1 ; Set firmware compatibility to look like RepRapFirmare

;*** The homed height is deliberately set too high in the following - you will adjust it during calibration.
M665 R105.6 L288 B105 H250 ; Set delta radius, diagonal rod length, printable radius and homed height
M666 X0 Y0 Z0 ; Put your endstop adjustments here, or let auto calibration find them

; Network
M550 PMy printer ; Set machine name
M552 S1 ; Enable network
;*** Access point is configured manually via M587
M586 P0 S1 ; Enable HTTP
M586 P1 S0 ; Disable FTP
M586 P2 S0 ; Disable Telnet

; Drives
M569 P0 S0 ; Drive 0 goes forwards
M569 P1 S0 ; Drive 1 goes forwards
M569 P2 S0 ; Drive 2 goes forwards
M569 P3 S1 ; Drive 3 goes forwards
M350 X16 Y16 Z16 I1 ; Configure microstepping with interpolation
M350 E8 I0 ; Configure E axis microstepping to x8 with interpolation OFF
M92 X80 Y80 Z80 E2081 ; Set steps per mm
M566 P1 X240 Y240 Z240 E6 ; Set maximum instantaneous speed changes (mm/min)(Jerk)
M203 X12000 Y12000 Z12000 E2400 ; Set maximum speeds (mm/min)
M201 X660 Y660 Z660 E120 ; Set accelerations (mm/s^2)
M906 X1000 Y1000 Z1000 E400 I30 ; Set motor currents (mA) and motor idle factor in per cent
M84 S30 ; Set idle timeout

; Axis Limits
M208 Z0 S1 ; Set minimum Z

; Endstops
M574 X2 Y2 Z2 S1 ; Set active high endstops

; Z-Probe
M558 P5 R0.4 H2 F1200 T6000 ; Set Z probe type to effector and the dive height + speeds
G31 P100 X0 Y0 Z-0.1 ; Set Z probe trigger value, offset and trigger height
M557 R90 S20 ; Define mesh grid

; Heaters
M307 H0 B0 S1.00 ; Disable bang-bang mode for the bed heater and set PWM limit
M307 P0 A191.5 C1032.9 D5.1 ; CALIBRATION my
M305 P0 T100000 B4138 C0 R4700 ; Set thermistor + ADC parameters for heater 0
M143 H0 S120 ; Set temperature limit for heater 0 to 120C
M305 P1 X200 ; Set thermistor + ADC parameters for heater 1
M143 H1 S280 ; Set temperature limit for heater 1 to 280C

; Fans
M106 P0 S0 I0 F500 H-1 ; Set fan 0 value, PWM signal inversion and frequency. Thermostatic control is turned off
M106 P1 S1 I0 F500 H1 T45 ; Set fan 1 value, PWM signal inversion and frequency. Thermostatic control is turned on
M106 P2 S0 I0 F35 H-1 ; Set fan 2 value, PWM signal inversion and frequency. Thermostatic control is turned on

; Tools
M563 P0 D0 H1 F2 ; Define tool 0 + DEFAULT Fan0 ->forwarded to-> Fan2!!!
G10 P0 X0 Y0 Z0 ; Set tool 0 axis offsets
G10 P0 R0 S0 ; Set initial tool 0 active and standby temperatures to 0C

; Automatic saving after power loss is not enabled

; Custom settings are not configured

; Miscellaneous
T0 ; Select first tool
M501 ; new commands override the ones earlier in your config.g

arhi

you need to reduce the M201 E120 to something smaller
F3D is 40:1 so you need super fast motors in order to get super high speeds

This works for me

M566 E6.00                ; JERK 
M203 E1000.00       ; speed
M201 E120.00            ; accel

but I changed 4-5 different motors till I found a motor that can handle this speeds .. with regular nema17 I could not handle even half ... note jerk6 is important

vapvap

@dc42 Thanks for your advice, but in your opinion, how much (mm/s or may be "steps") can acceleration be reduced?

vapvap

@arhi Wow!
Could you share more information about your wonderful motor?

arhi

@vapvap said in Retract problem (Flex3Drive):

@arhi Wow!
Could you share more information about your wonderful motor?

no .. can show you image but it looks like all the others ... I have ton of new and second hand motors and this one was second hand, probably taken from a 2d printer or copier .. no data on the motor itself... most of the second hand motors I have are "brand name" as they are "saved" from some expensive big copier, printer's etc... usually made in japan or made in USA .. problem is that number of them have those markings "lost" as the sticker quality was not that high and oil content in storage containers was

I tried originally 400 steps/rev motor and it was awful, I could not get anything to work and firmware was shooting out the errors about back emf.. than I tried few other and none worked, I had issues with acceleration, max speed etc... then I lineup all the nema17 I had and measured inductance of each of them and used the one with smallest inductance and that one works. I think 120mm/sec/sec is too much even for this motor but it kinda works, rest is ok. JERK is important, anything higher than 6 and it will not work, 6 is highest value that works, this was copied from my "backup" IIRC the running config on the printer is jerk 4 and accel 90 as those values are much more stable

arhi

@vapvap btw Jason from f3d is selling some nema8 motors that are supposed to have super low inductance and can accelerate and run super fast. you might want to contact him about that, it's possible best solution for this (he also have a way of using them as "direct drive" with flex3drive as they are very light, so you don't need the cable but have motor directly on the G5)

Carlo

@vapvap

Apologies for the delay Chrimbo an all
your steps should be set to 1900 measure your filament at a few places over a few meters take the average and change your slicer filament setting to the average.

M201 X660 Y660 Z660 E40 is what it should be
Also what slicer are you using ?
try Prusa if not using it already with firmware retractions on
and the following in your config.g
below ; Custom settings
;Retraction settings
M207 S1.5 R0 F900 Z0.4 ; G5 retraction setting
Let me know if this helps or not I also am able to run extruder motor @300ma for .4 and
400ma for .8 nozzles my motor is from an old Anet A8 and is basically silent with those settings

Try upping you extruder motor to 600ma just to see if the stalling reduces if the settings above don't help with stalling if having to up the motor power helps get a lower inductance motor but those accel settings should work

gnydick

You need the following to make remote drive work

low micro stepping
low current
low acceleration
1.8° motors

The 40:1 gear ratio is not really well matched to our standard stepper motors. In order to get any speed at the print end, the motor has to go RIDICULOUSLY fast. Once the stepper is going that fast, it has no torque. So high acceleration is impossible.

I have the same flex 3 drive and found it unusable because retractions and extrusions were so slow.