3d Benchy Question

wingtip

Hello all,
Ive recently got my custom printer up and running with a duet wifi and the duex expansion. Other key features are a BMG extruder w/V6. The file in question is the infamous benchy.
Settings:
slicer- S3D
speed-50mm/s
Nozzle-.3
Layer Height- .15
Retraction Distance- 1.0mm
Retraction Speed- 30mm/s
Temps- 236/90
Part Fan Speed- 0% first layer, 50% layer 3 and beyond
Material- Zylatec PETG

Accel and Jerk settings

M566 X300     Y600     Z180    E120            ; set maximum instantaneous speed changes (mm/min)
M201 X500     Y500     Z20     E250            ; set accelerations (mm/s^2)

This was the first benchy printed on this machine having only printed calibration cubes before it. The print came out exceptionally well for the first real print on the machine. It had almost no stringing. However, there are two areas I'd like to fix if anyone has some input.

First and foremost the bow area has an issue. Looking at the photo, would this be from under extrusion or a part cooling issue, or something else ???? Other parts of the model show good extrusion with no holes or gaps. This makes me lean towards a cooling issue...

The other minor issue are these 3 tiny bumps on the roof. I printed a second benchy and it looks like the nozzle sat there to long. Should i increase the retraction distance? Or is there no solution to this as its just S3D way of doing things?

The reflections off of petg always make closeups look like total crap but I assure you in person these benchys look pretty amazing and zero stringing. I should primer one to dull it for more detail.

The benchy looks very small on my printer lol, like its out to sea.

cosmowave

@wingtip
The "not nice bow" of the benchy in the first picture seems to be a cooling issue.
I think, it's the opposite side of your cooling duct which have a bad surface.

You can try to run the cooler faster (if it is possible), improve the airflow or add a cooler on the opposite side...

wingtip

@cosmowave Interesting... i will increase the fan on the next print for sure but i may also turn the model around. This isnt the best cooler and im still looking for a better design that will work with my setup.

Blacksheep99

Agree with the cooling comment. It may be your pictures but looks like possibly over extruding as well?

wingtip

@blacksheep99
Hmm, i'm not sure its over extruding and here's why i think that... i started printing 20mm calibration cubes to rough dial in the machine. the top layers were having gaps and holes. I slowly bumped up the extrusion till the tops had no gaps or holes... my extrusion multiplier right now is at 1.10. I wouldn't think that's to high but i'm no expert and is why i'm here to get some guidance.

Blacksheep99

@wingtip 1.1 is a lot in my experience, normally I'm below 1. What's your infill on those cubes? how many top layers?

Decent site for helping get this setup. Sorry if I'm teaching you to suck eggs....

https://teachingtechyt.github.io/calibration.html

edit: also, is your filament new? or at least at your sure it is dry?

wingtip

@blacksheep99
It is older filament at the end of the spool..wanted to burn it up before opening another spool.
Infill- 20%
top layers-4
bottom layers-3
outline layers-4

Phaedrux

Can you post your full config.g?

The hull is definitely cooling and overhang performance issue. It's the hardest part of the model to print. I would suggest trying to print 2 of them side by side to increase the layer times and allow for more cooling. Unless you're always going to be printing single tiny boats on that giant printer I don't think it will be much of an issue.

The top surface bumps I think are likely due to excessive dwell time on retractions/travels due to the slow Z and E limits you've got set.

wingtip

@phaedrux

; config.g
; executed by the firmware on start-up
 
; general preferences

G90                                            ; send absolute coordinates...
M83                                            ; ...but relative extruder moves
M550 P"The Big One"                            ; set printer name
 
; communications

M552 S1                                        ; enable network
M586 P0 S1                                     ; enable HTTP
M586 P1 S0                                     ; disable FTP
M586 P2 S0                                     ; disable Telnet
M575 P1 S1 B57600                              ; enable support for PanelDue
 
; drives

M569 P0 S0                                     ; physical drive 0 goes reverse
M569 P1 S0                                     ; physical drive 1 goes reverse
M569 P2 S1                                     ; physical drive 2 goes forwards
M569 P3 S0                                     ; physical drive 3 goes reverse
M569 P4 S1                                     ; physical drive 4 goes forwards
M569 P5 S0                                     ; physical drive 5 goes reverse

M584 X0:3 Y1 Z2:5 E4                           ; set drive mapping

M92  X391.113 Y78.812  Z392.117 E397.022      ; set steps per mm
M203 X4000    Y4000    Z800    E1200           ; set maximum speeds (mm/min)
M566 X300     Y600     Z180    E120            ; set maximum instantaneous speed changes (mm/min)
M201 X500     Y500     Z20     E250            ; set accelerations (mm/s^2)
M906 X1400    Y1000    Z700   E1000     I30    ; set motor currents (mA) and motor idle factor in per cent

M84 S30                                        ; set idle timeout

M350 X16 Y16 Z16 E16 I1                        ; configure microstepping with interpolation
 
; axis limits

M208 X0:655 Y0:440 Z0:400                      ; set axes min/max
 
; endstops

M574 X1 S1 P"!xstop+!e0stop"                   ; configure active-high endstops for low end on X
M574 Y1 S1 P"!ystop"                           ; configure active-high endstop  for low end on Y

; Z probe

M98 P"probe_config.g"                          ; configure Z probe by invoking gcode file
 
; bed heater

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 R0.257 C549.0 D2.37 S1.00              ; disable 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

; tool heater

M308 S1 P"e1temp" Y"thermistor" T100000 B4725 C7.06e-8 ; define E1 temperature sensor
M950 H1 C"e1heat" T1                           ; create nozzle heater output on e0heat and map it to sensor 1
M307 H1 R1.373 C172.7 D8.28 S1.00 V11.7        ; disable bang-bang mode for heater  and set PWM limit
M143 H1 S280                                   ; set temperature limit for heater 1
 
; part cooling fan

M950 F0 C"fan0" Q500                           ; create fan 0 on pin fan0 and set its frequency
M106 P0 S0 H-1                                 ; set fan 0 value. Thermostatic control is turned off

; tool cooling fan

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
 
; tool 0

M563 P0 D0 H1 F0                               ; define tool 0
G10 P0 X0 Y0 Z0                                ; set tool axis offsets
G10 P0 R0 S0                                   ; set tool active and standby temperatures
T0                                             ; set tool active

Phaedrux

I'd try these changes.

M203 E6000
M566 E3000 P1
M201 Z200 E3000

These changes would make your extruder and z axis a bit more responsive. M566 P1 enables jerk between all move types which basically makes transitions to and from travel moves a bit quicker, which can help on those blobs on the surface.

Now might also be a good time to tube retraction and pressure advance.

I know your axis are fairly large and slow, so conservative jerk and accel on the X and Y are understandable. But you may still want to play with that a bit to see what you can get away with.

These macro files can help in live tuning things.

https://forum.duet3d.com/topic/6181/tuning-macros-menus-accel-jerk-retraction-pressure-advance?_=1622238917018

wingtip

@phaedrux
When the current print finishes i will upload these changes. However, what did you mean by its time to tube retraction??

Phaedrux

tune! Not Tube.. sorry.

droftarts

@wingtip what is the printing order per layer? I’m not familiar with S3D, but you can change it on other slicers. It can help overhangs if you print inner perimeter before outer perimeter. But can negatively effect the dimensions, as outer perimeter can be pushed out further if overextruding.

Ian

wingtip

@droftarts
in S3D its called outline direction and the options are outside-in, or inside- out.
Mine is defaulted to inside-out.

The print i had going last night finally finished. I will implement some of the changes suggested in the thread now for the next print. Its very close to being dialed in. The part last night came out great and was dimensionally accurate. It had very few minor defects that doesn't affect the usability of the part at all.

Will make the changes and post the results.

Phaedrux

@wingtip said in 3d Benchy Question:

Nozzle-.3

Are you going to be using a 0.3mm nozzle long term? Seems an odd choice for such a large printer?

wingtip

@phaedrux
I was planning on using it for detail... i care more about detail than speed. However, when i plugged in my model i built this printer for into S3D, I was quite shocked at the print time. It was like 13 days! Soooo I will more than likely break it into sections.

Here is another benchy i just finished after making some of the adjustments suggested. I also turned the benchy 90 deg to aid in the cooler nozzle hitting the bow. Those first tests again were with zylatec black petg, this is matterhackers white petg. Also older filament and white isnt the easiest to print in.

Phaedrux

13 days... wow. You'd be surprised the detail you can get from a 0.6mm nozzle. Unless you're printing minis with very fine features.

wingtip

@phaedrux
can you even run a .6 on a v6 or would i have to switch to a volcano, which means also making another new part cooler and a new bl touch bracket.... uggg lol

Phaedrux

@wingtip I run a 0.6 on a V6 titan aero. No problem. 10 to 12 cubic mm per sec of flow without issue. Gets me 60-70mm/s and 0.3 layer heights.

wingtip

@phaedrux
using your numbers i plugged them in to see what the time difference would be.. holy cow.. 300 hours to 55 lol.... but im worried about the detail ... i want to take this finished part and make a fiberglass mold... the .3 nozzle parts when printed look fine for the detail.... a .6 though i worry.. can you post some pics of some .6 nozzle prints??? Cause the print time does look wayyyy better.. Other wise im going to have to split this down to more manageable print times.