Gaps, Under-extrusion after long travel move

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    Hi Stepan,

    I’m having what I believe is a pretty unique issue.

    Printer: Hictop i3
    Filament: Amz3d PLA – Yellow
    Temp: 240c
    Bed Temp: 65c

    I’m using mostly your stock values for Simplify3D – with my own retraction and speed settings that have been tested through what is now 45 tests of one of the wing profiles for the Stearman.

    The problem is that the very start of a new outer shell on a thin wall segement after a relatively long travel move – say from the leading edge spar back to the trailing edge start, the first several MM of the line are under extracted. I’ve gone through 45 revisions of my settings to try and get rid of this issue.

    I’ve increased the prime amount after retraction – I’m currently at 0.14mm – but if I increase it much beyond that, I get bulges in other areas that go through the wing. It does not under-extrude at any other time, only after a long delay (like a long travel move). I’ve also mitigated it somewhat by increasing my travel speed to pretty much maximum for my machine (140mm/s). I’ve also increased the bonding on thin sections like that by increasing the temperature, but much beyond 240c and it will be pretty terrible at bridging. 240c is already 30c above the maximum advised temperature for this filament.

    I’m at a loss, I don’t know what else to try at this point. My extrusion values are 0.40 nozzle, 1.03x multiplier which gives me EXACT weights for wings. 0.42 extrusion width.

    Underextrusion at Line Start

    Stepan Dokoupil

    Hello David, yes this looks like start point under-extrusion, there is two reason: a filament leak when nozzle is traveling (in detail look you can see it) increasing retraction distance or lowering temperature should solve it.
    Or increased resistence in HotEnd/Nozzle (delayed delivery of the filament) so when starting printing just after retraction we dont have enough amount of filament. When is our Extruder/HotEnd/Nozzle in good condition this should not have happened (also filament have some role). This deficiency becomes visible when you start with our Thin Wall printing… you can have a look here in retraction topic

    Now the solution (I guess the second reason ): try decrease retraction speed to 15-20mm/s OR decrease print speed to 40mm/s or set layer height to 0.2mm instead default 0.25mm OR try different PLA brand

    You can also post here your Factory file I can have a look on it, let me know… (also your retraction distance is impprtant we recomment 0.7-1.5mm for direct drive)


    Hi Stepan,

    Last night I tried replacing the nozzle and throat, despite them being in what I assumed was good working order. It seems to have completely eliminated the issue. I believe it was pulling air into the nozzle perhaps because it wasn’t fully seated or the threads were worn. I noticed there were a lot of air bubbles in my thin wall prints previously which also seem to be completely gone after the replacements.

    Now I have to re-dial my settings, I’ll be turning down the prime value a lot, I was up to .16 and it leaves a lot of zilts on the wing. What is the reason your files are set at .12? Is that just for extra filler on the wing support?

    I’ll also be turning it down from 240c since its a little stringy inside the wing. VERY strong though.

    Ricardo Mola

    Hi, I have the same problem with some of parts, so I will send my printer details and FFF file , as you had mentioned in the videos.

    Firmware – Marlin

    Material – pla
    temp – 200c

    I´m try to upload the FFF file but I got an error message , how can I send it


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    Stepan Dokoupil

    helo, ZIP it, and please Factory file is better, and your printer spec or brand, thank you

    Ricardo Mola

    ok , here the print specification and the FFF file . thanks again

    Printer – 3DMachine ONE

    Printing Area (1 Extruder):
    300 mm x 200 mm x 200 mm (x, y, z)
    Filament Diameter:
    1,75 mm
    Print head nozzle:
    0.4 mm
    Print Speed:
    Average Print Speed:
    35mm / s – 80mm / sec
    Positioning resolution:
    X – 0.0125mm
    Y – 0.0125mm
    Z = 0.05 mm
    Layer height:
    0.06 mm – 0.35 mm
    Maximum Temperatures:
    Heated table:
    Up to 110ºC
    Print Head:
    Up to 250ºC
    110V / 220V
    12v 25A
    Maximum consumption:
    150w / H (PLA)
    250w / H (ABS)

    Printer Console:
    Repetier Host

    CURA (Repetier Host Version)
    File Extension (3D):
    .STL (StereoLithography)
    .OBJ (Object)

    SD card
    Custom Marlin

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    Stepan Dokoupil

    Hello, thanks for informations, it looks like your printer si compatible with our Gcodes, try open the printer doors there is maybe to hot air in inner space of the printer it can helps. I suppose you did use our prepared Gcodes, yes? If yes, please try decrease bed temperature by 5 celsius, you an do this just before print on your printer LCD panel…
    Or try different PLA brand

    Kai Krzyzanowski


    I’m from germany and new here.
    I am printing the Spitfire and very happy with the parts. But if I print more parts at the same time I have the same problem:
    After a long travel from one part to the other I have under extrusion on the first 10mm at the beginnend on every Layer on every Part. If I print only one part, I dont have this problem. Instead I have sometimes very small overextrusion where the inner walls touch the outer perimeter.

    I have a Geeetech Prusa I3 Pro B with direct extruder.
    Printing speed: 50 mm/s
    Travel speed: 120 mm/s
    Retraction: 2 mm with 40 mm/s and z hop
    Temp: 210/60 C with depron around the printer works good to prevent warping.
    Other slicer settings like yours in cura.
    But in cura there is no Setting like “extra extrusion after travel” I think ?!

    Thanks for your help.
    Best regards,

    Stepan Dokoupil

    Hello and thanks, try lower retraction to 1mm, 230 is a good temperature for PLA or 220…, did you try our prepared Gcodes already (included in package)? It should work on your machine…

    Kai Krzyzanowski

    Okay i will Test this 🙂
    I am now printing the Fuselage 2 Gcode of your ready gcodes (Spitfire) and the Printer is printing two Perimeters ? Is this normal ? I thought the outer Perimeter is always 1 perimeter thick?
    Trank you,

    Kai Krzyzanowski

    Okay sorry ist only the first 15 layers that are double-printed 🙂

    Ricardo Mola

    some of tips were very helpful and I have good results printed now , one modification from my side was change layer from 0.25 to 0.2 and new nose section ( long ) for my spitfire been amazing, but my concern is the weight, into the documentation you mentioned that part should have 48g and I got 56g.

    thanks in advance

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