I've built a 300 x 300 x 300 D-Bot and I'm using an E3D V6 full with a Titan extruder. Build recently finished and I'm working on the tuning and calibration. I've gone through calibrating extruder, X, Y, and Z steps, everything checks out as far as I can tell. The problem I had (but never resolved) with PLA was jamming in the heat break, so I switched to PETG. Results are marginally better - definitely get a better first layer, but the PETG also apparently jams after less than 10 min of printing and the Titan starts clicking. I've tried: - bumping temperature up and down - reapplying thermal paste to the heatbreak - repositioning the fan - setting retraction to 0.8mm Here are some pictures of the setup: PTFE Tube is fully seated - this is a picture when I was taking apart the hotend: The most recent test was with PETG - print temp 250c, bed 70c. This first layer generally looks good until the filament stopped extruding and the Titan started clicking. General build is: "D-Bot Blue" D-Bot build 300 x 300 x 300 Hotend: E3D V6 (full) Nozzle: 0.4mm Extruder: Titan Print Bed: Mic6 Aluminum (8 x 325 x 325) Print Bed Heater: Keenovo Silicone heater (120v, 750w) Controller: DuetWiFi (firmware 1.19) Steppers: 1.8 degree, 2.0 amp, 84 oz Leadscrews: 8mm x 400mm - single start, 2mm / turn - w/anti-backlash nuts Filament width: 1.75mm Slicer: Simplify3D Layer Height: 0.2mm Extrusion Multiplier: 1.0 Extrusion width: 0.5mm Tuning To Date: X, Y, Z steps / mm Extruder steps / mm Autotune PID Extruder Autotune PID Bed Pressure Advance: M572 D0 S0.1 Here is the config.g from the firmware: ; Configuration file for Duet WiFi (firmware version 1.19) ; executed by the firmware on start-up ; ; generated by RepRapFirmware Configuration Tool on Sun Oct 22 2017 14:48:43 GMT-0500 (Central Standard Time) ; General preferences M111 S0 ; Debugging off G21 ; Work in millimetres G90 ; Send absolute coordinates... M83 ; ...but relative extruder moves M555 P2 ; Set firmware compatibility to look like Marlin M667 S1 ; Select CoreXY mode M208 X0 Y0 Z0 S1 ; Set axis minima M208 X296.5 Y295 Z298 S0 ; Set axis maxima ; Endstops M574 X1 Y2 Z1 S0 ; Define active low and unused microswitches M558 P0 X0 Y0 Z0 H5 F120 T6000 ; Set Z probe type to switch, the axes for which it is used and the probe + travel speeds G31 P600 X0 Y0 Z2.5 ; Set Z probe trigger value, offset and trigger height M557 X15:265 Y15:265 S20 ; Define mesh grid ; Drives M569 P0 S1 ; Drive 0 goes forwards M569 P1 S1 ; Drive 1 goes forwards M569 P2 S1 ; Drive 2 goes forwards M569 P3 S1 ; Drive 3 goes forwards M350 X16 Y16 Z16 E16 I0 ; Configure microstepping without interpolation M92 X100 Y100 Z1600 E400.97 ; Set steps per mm (estimate for Titan Extruder) M566 X900 Y900 Z12 E120 ; Set maximum instantaneous speed changes (mm/min) M203 X900000 Y900000 Z300 E1740 ; Set maximum speeds (mm/min) M201 X1500 Y1500 Z250 E259 ; Set accelerations (mm/s^2) M906 X1200 Y1200 Z1200 E1600 I30 ; Set motor currents (mA) and motor idle factor in per cent M84 S30 ; Set idle timeout ; Heaters M143 S260 ; Set maximum heater temperature to 260C M301 H0 S1.00 P10 I0.1 D200 T0.4 W180 B30 ; Use PID on bed heater (may require further tuning) M305 P0 T100000 B3950 C0 R4700 ; Set thermistor + ADC parameters for heater 0 M305 P1 T100000 B4138 C0 R4700 ; Set thermistor + ADC parameters for heater 1 ; Tools M563 P0 D0 H1 ; 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 ; Network M552 S1 ; Enable network M586 P0 S1 ; Enable HTTP M586 P1 S1 ; Enable FTP M586 P2 S0 ; Disable Telnet ; Fans M106 P0 S1 I0 F500 H-1 ; Set fan 0 value, PWM signal inversion and frequency. Thermostatic control is turned off M106 P1 S1 I0 F500 H0:1 T45 ; Set fan 1 value, PWM signal inversion and frequency. Thermostatic control is turned on M106 P2 S1 I0 F500 H0:1 T45 ; Set fan 2 value, PWM signal inversion and frequency. Thermostatic control is turned on ; Custom settings ;Endstop set to Active Low ;Geometry refined (X, Y, Z max) ;Z home trigger height at z axis = 0.1 ;Motor milliamps = 1200 ; Selected preset thermistor coefficient (e3D) ; Extruder - 400.97 steps / mm (calcuated) ; X and Y motor steps / mm set to 100 (calculated) ; Z steps / mm = 1600, set Extruder fan to 100% ; M501 to load override params ; Keenovo Bed parameters - P0 T100000 B3950 C0 R4700 ;Enable Pressure Advance M572 D0 S0.1 ; Miscellaneous M501 ; Load saved parameters from non-volatile memory T0 ; Select first tool Any recommendations would be greatly appreciated.