@Slzer said in 600mm bowden setup pressure advance calibration:

Have i done something wrong here?

That was pretty much my feeling when I set up pressure advance, and I'm still not completely convinced. FWIW I have a similar length bowden (can't measure it because I'm at work). I ended up converging on S1.4 just by printing some square towers and watching the corners. I'm replacing the stepper though, so that could change soon. For background, my extruder is non-geared, 1.75mm, and currently uses a 1.8 degree stepper that is barely strong enough.

I had the same observation that the E stepper kind of goes crazy on small areas. High S values can be demanding. I found that it is very important to dial in E axis current/speed/acceleration/jerk properly. If the stepper can't keep up, the E axis can become the limiting factor for overall print speed, or it can miss steps.

Thanks guys. I am running 3.1.1 now with 16x microstepping (with interpolation) and it is working fine. I noticed that this version can't handle full speed on X and Y at 256x microstepping like version 2.02 did, but it sounds like 16x is kind of the norm.

In retrospect, that was really old firmware. I just didn't think to check, since the board was a relatively new purchase.

Noise is the biggest thing for me.

Would you guys expect much of a noise difference between 16x with interpolation and 256x assuming the CPU can keep up? I'm on a Duet2 running 0.9 degree steppers and rapid movements get limited when I go to 256x. For whatever it's worth, I feel like the Prusa mk3 machines are quieter than mine for rapids, but I realize there are a lot of other variables as well.

When the printer retracts to make a rapid travel move, it then has to un-retract before it can keep putting down plastic. By re-extrusion, I guess what I really mean is the un-retraction event and the extrusion immediately after.

I found that after the un-retraction, it would often take some time for the plastic to start flowing again, but the printer would already be started on the perimeter or whatever. This would tend to leave gaps and thin spots. The problem was worse with PLA, as you would expect with heat creep.

@jens55 said in Slice RepRap Heat Break in E3Dv6:

I am assuming that you are trying this to improve heat break performance ?

Pretty much this. With the previous hotend I had problems with re-extrusion after retraction. It was one of the early E3Dv6 models, and I know some of those had issues. Maybe a new standard heat break would be fine, but I wanted to give the bi-metal one a try. The boron nitride is still drying, but I'll run some PLA through it this weekend and report.

Has anyone tried using the RepRap version of the Slice Copperhead heat break in an E3Dv6? Mine just came. Apparently the Copperhead heater block has a longer threaded section than E3D. It sticks out a bit, but I'm going to to grease it with boron nitride and try it anyway.

Thanks guys. I am running 3.1.1 now with 16x microstepping (with interpolation) and it is working fine. I noticed that this version can't handle full speed on X and Y at 256x microstepping like version 2.02 did, but it sounds like 16x is kind of the norm.

In retrospect, that was really old firmware. I just didn't think to check, since the board was a relatively new purchase.

Maybe I answered my own question. I'm going to upgrade the FW to 3.0 and see what happens.

The behavior occurs if I run the macro after a reset, home Z, and execute a G0 Z10 to provide room for travel. Using H1 vs. S1 doesn't make a difference.

My firmware version is 2.02(RTOS) (2018-12-24b1)

Config file:

; General preferences
G90                                     ; send absolute coordinates...
M83                                     ; ...but relative extruder moves
M550 P"OwlFab1000"                      ; set printer name



M667 S1                                 ; select CoreXY mode

; Network
M552 S1                                 ; enable network
M586 P0 S1                              ; enable HTTP
M586 P1 S0                              ; disable FTP
M586 P2 S0                              ; disable Telnet

; Remove these for DHCP
M552 S0 
M552 S1 P192.168.0.10

; Drives
M569 P0 S1                          
M569 P1 S0                        
M569 P2 S1                             
M569 P3 S1                             
M569 P4 S1                              
M584 X0 Y1 Z2:4 E3                         ; set drive mapping
M350 X256 Y256 Z256 E16 I0                 ; configure microstepping without interpolation
M92 X2560.00 Y2560.00 Z25600.00 E268.63    ; set steps per mm M203 X9000.00 Y9000.00 Z1000.00 E3000.00   ; max speed (mm/min)
M566 X800.00 Y800.00 Z150.00 E1500.00      ; jerk (mm/min)
M203 X9000.00 Y9000.00 Z1000.00 E3000.00   ; max speed (mm/min)
M201 X1000.00 Y1000.00 Z150.00 E1800.00    ; set accelerations (mm/s^2)
M906 X800 Y800 Z1200 E1200 I30             ; set motor currents (mA) and motor idle factor in per cent
;M906 X500 Y500 Z600 E600 I30              ; stealth mode
M84 S10                                    ; Set idle timeout

; Axis Limits
M208 X0 Y0 Z0 S1                        ; set axis minima
M208 X250 Y195 Z268 S0                  ; set axis maxima

; Endstops
M574 X1 Y1 Z2 S1                        ; set active high endstops

; Z-Probe
M558 P0 H5 F120 T6000                   ; disable Z probe but set dive height, probe speed and travel speed
M557 X15:215 Y15:195 S20                ; define mesh grid

; Heaters
M305 P0 T100000 B4138 R4700             ; set thermistor + ADC parameters for heater 0
M143 H0 S120                            ; set temperature limit for heater 0 to 120C
M305 P1 T100000 B4138 R4700             ; 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

; 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


T0                                      ; select first tool 
M203 X9000.00 Y9000.00 Z1000.00 E3000.00   ; max speed (mm/min)
; Stall detection
; M915 X Y S5 R2 

; Pressure advance
M572 D0 S1.

My Z home macro is:

; homez.g
; called to home the Z axis
;
; generated by RepRapFirmware Configuration Tool v2.1.8 on Tue Mar 31 2020 14:27:47 GMT-0700 (Pacific Daylight Time)
G91              ; relative positioning
;G1 S2 Z5 F600   ; lift Z relative to current position
G0 S1 Z295 F800  ; move Z up until the endstop is triggered
G92 Z268         ; set Z position to axis maximum 
G1 S2 Z-5 F6000  
G90              ; absolute positioning

Something is limiting my Z homing feed rate, and I can't figure out what. Is there anything other then the G0/G1 F argument or G203 that could do this? I made a macro that demonstrates my issue:

G91              
G0 S1 Z100 F1000  ; This seems to run at about 500 mm/min
G90 

G0 Z0 F1000  

G91              
G0 Z100 F1000     ; This runs at full speed      
G90 

G0 Z0 F1000

@Phaedrux
Thanks for the tip. I will give it a try.

@Slzer
It does seems weird that your towers look the same. When I was printing the hollow towers, the main thing I was watching was the corner where the layer transition happened. On my printer, I was getting a blob there without using advance. Turning it up too high resulted in a gap. If it wasn't for that blob, I probably wouldn't have even bothered.

One thing I appreciate about the Duet is that you can change most of the motion settings on the fly. If you paste it into the web interface while printing, you can observe the effects immediately without having to start a new print. Then when you have something that works, you can edit config.

I just replaced all of my steppers. Things are still kind of in flux, but the benchy printing right now looks good so far. Here are the relevant lines from my config.g. As you can see, I went down to S1.

M584 X0 Y1 Z2:4 E3                         ; set drive mapping
M350 X256 Y256 Z256 E256 I0                ; configure microstepping without interpolation
M92 X2560.00 Y2560.00 Z25600.00 E4298      ; set steps per mm 
M566 X1000.00 Y1000.00 Z500.00 E1000.00    ; jerk (mm/min)
M203 X18000.00 Y18000.00 Z1000.00 E3000.00 ; max speed (mm/min) 
M201 X2000.00 Y2000.00 Z300.00 E1200.00    ; accelerations (mm/s^2)
M906 X800 Y800 Z1200 E1200 I30             ; set motor currents (mA) and motor idle factor in per cent
M84 S10                                    ; Set idle timeout

; Pressure advance
M572 D0 S1

Edit: I should say that my extruder max speed probably needs to be reduced, since I'm seeing some missed steps.