Dim3nsioneer

It might be something you already thought of days ago, but is it actually the same with any filament?

illuminarti was right once more... After being away from my UM1 for more than a week I finally found the time this morning to find a proper solution for the central bore closing issue. The last time I added a lateral movement I indeed caught the wrong direction and produced a perpendicular movement... :wacko: This time I added a movement in exactly the same direction as the last printing move. I skipped the velocity and the extrusion argument (F and E). Obviously, the E jerk was large enough to allow the additional G0 movement to be performed without decelerating the print head. And this is the result: So the issue is solved. It's now printing the whole thing including the 133mm I cut off for the test...

@G0ultimaker: Would you mind setting the permission of your sketches to 'public'? They look quite interesting from the thumbnails...

It might even be necessary to thicken it up to 0.41mm...

Mainly the travel speed in the advanced section. Set it to 150mm/s.

An dieser Stelle hat es ziemlich flache Überhänge. Mit einem kühlenden Luftstrom ist das schon anspruchsvoll genug; ohne wirds extrem schwierig.Was passiert ist, dass sich das überhängende Material stark nach oben rollt. Die heisse Düse macht die Rolle immer schlimmer. Ein Lüfter würde das Material schnell abkühlen und hart werden lassen, bevor es sich rollen kann. Meine Empfehlung: So rasch wie möglich einen Lüfter mit geschicktem Fanduct an den Druckkopf dran machen. Und bis dahin eine provisorische Kühlung z.B. mit einem Kaltluftfön oder sonst einem Tischventilator von der Seite. Dabei muss allerdings um die Düse herum (z.B. mit Kaptontape oder auch mit dem blauen Malerklebband) eine Luftbarriere improvisiert werden. Ohne richtige Kühlung wird keine echte Freude aufkommen.

Most probably the white PLA has a larger diameter than the UM material. If you leave the diameter setting on your UM2 as it is, it will of course extrude more material per time. Or rather enough per time in your case as you suffered from underextrusion with the UM original material. However, gr5 described the way how to deal with underextrusion.

it sometimes leaves a string, yes. But in most cases this string can be cut away easily. Putting a standard behaviour in end gcode seems a bit risky to me as if forgotten there, it can do more harm than good with other prints. btw: I don't have to switch the flavour as I have an UM1...

The steps per mm value can be slightly different according to my own experience. I derived the 'correct' number for my UM1 by moving 150mm or 200mm and measuring the real distance. Maybe this works as well for you?

That's more or less what I've done so far. I will not print the whole part before I get reasonable results for the top. And I even found a tiny bug in Cura by doing so. And Daid already fixed it...

It's maybe worth mentioning that there are different types of stepper drivers. AFAIK the Ultimaker stepper driver have their own board design. It is pin compatible with the Pololu driver boards (and also run with a Pololu A4988) but may have a different way to set up the current and a different reference voltage maybe. On the Wiki page of which you posted the link, you have the different types on the bottom. Make sure you're not driving the driver significantly into overcurrent otherwise you really have to replace them. Although they are not too expensive, you would have to wait for the new drivers to arrive and couldn't use your machine... :sad:

Apropos Screenshots: Könntest Du die Bilder bitte noch auf 'public' setzen, sonst müssen wir uns mit den Thumbnails begnügen... danke! Die Werte passen zueinander. Zum Schichtenhaftungsproblem könntest Du ausprobieren, ob es besser ist, wenn Infill und und Shell gleich schnell gedruckt werden. Sonst hast Du die Situation, dass durch die Beschleunigung bei Beginn der neuen Shell das deponierte Material 'ausgedünnt' wird für etliche Zentimeter. Dadurch könnten solche Haftungsprobleme entstehen. Probier auch mal aus, ob bei einem anderen Object mit deutlich anderer Grundfläche die Haftungsprobleme exakt auf der gleichen Höhe auftreten. Falls ja, dann klemmt wahrscheinlich irgendetwas beim Drucktisch (Kupplung überprüfen; Starrkupplung, wenn ich es richtig sehe auf dem Thumbnail, oder?) und Du bekommst einen leicht zu hohen Layer mit entsprechend zu wenig Material.

Vielleicht habe ich es verpasst oder aber es fehlt immer noch die Angabe der Druckgeschwindigkeit? 210°C kann durchaus zu kalt sein. Bei 150mm/s würde ich jedenfalls kein schlaues Ergebnis erwarten. Das gleiche gilt für die Schichthöhe. Wie gross ist die?

There are two types of this item profile. The one shown and printed by nudelmannrichter is the light one. The heavier one is also more sturdy. Maybe that one has some more use cases when printed... However, there are additional plastic parts for item profiles which might actually be printed.

Hmmm... could be I added a movement perpendicular to the last printed segment...silly me... :roll: I have to check. The x/y jerk should be big enough as the last segment is printed with 10mm/s (I think I have it on 20mm/s). Immediate retraction certainly is a no-go as Marlin then makes the print head stop after the last segment (due to what I call synchronizing; it's the trapezoid thing in planner.cpp; do you mean this with 'blending'?). btw: would the fw retraction (G10/11) also cause this...?

You're absolutely right. I thought of that as well. The 'problem' is the synchronization of the axes in Marlin for both G0 and G1 moves. :huh: Within the very last G1 cmd of the print itself, there is a small lateral movement and a positive e movement. If I now add another G0 or G1 cmd with a lateral movement and a non-positive e movement (i.e. no e or negative e) then Marlin stops not only the e axis but all other axes as well due to synchronization. However, only the shortest stop on the top makes the material (_XT, that's the reason why I didn't show an image as you would see nothing due to partial transparency) melting again, at least enough to partially close the bore. The only way around I see right now is to add another G0/G1 lateral movement with a positive e step, i.e. keeping the extrusion going on as long as the nozzle is close to the top, e.g. for a few mm and then retract the filament and so on... But there may be other options I haven't thought of... :???:

Meine Erkenntnisse gehen in eine ähnliche Richtung wie die von Burki. Zwar drucke ich auf Basalt und nicht auf Glas, dürfte aber kein allzugrosser Unterschied sein. Die Wichtigkeit des Levellings kann ich nur unterstreichen. Mit Spülmittellauge habe ich schon gute Erfahrung gemacht; mit Alkohol eher nicht. Grundsätzlich versuche ich, möglichst die Glasoberfläche nicht mit den Fingern zu berühren.

I assume you mean 30mm/s print speed, not travel speed. Travel speed is the speed your UM2 uses when moving between printing. Travel speed should be 150mm/s or even higher. Actually 210°C is ok for PLA, however you might even lower it a bit, maybe to 200°C if you're really printing @ 30mm/s. Or you could increase the print speed while staying @ 210°C to something like 50mm/s. Lowering the temperature is also what you should do for improving the antennae. I suggest you use the TweakAtZ plugin which is part of Cura 14.03 and change the temperature to 190°C at the height where the antennae begin.

Suboptimal PID parameters... you may try to use M303, but please only if you feel safe with it...

Hi there Various people had difficulties with printing a very small top layer without getting a blob at the end. A good way around that problem usually is to reduce speed and temperature. I now have a print to do with a small dome on the top and exactly in the center of the dome is a vertical bore which must not be closed. As it is very difficult to see it from the actual print, I show you a screenshot of the layer view. The problem now is that after printing the last bit of the last layer, the print head stops, retracts and then lifts. The time the hot nozzle spends there is enough to melt enough material for at least partially closing the central bore. These are the constraints: - the central bore has to be there with this size - the print has to be oriented like that What would you do to solve this situation? Any idea for tweaking, by plugin, manually in the Gcode or by hardware is welcome, especially if it based on your personal and practical experience. For me, the long term solution is clearly a distinguished implementation of the G0 commands in Marlin which allows direction change in one axis (extruder) without changing the speed on other axis (x/y). But that's something for the future... and not the work-around I'm looking for right now.

And print speed in mm/s please...

Klingt jetzt ein bisschen nach klassischer dummer Support-Rückfrage: Ist der lock-Riegel der SD-Karte sauber auf der richtigen Position?

Die Reduktion des Retract-Sppeds könnte durchaus einen Unterschied machen. Bei meinem UM1 versagt 40mm/s, 30mm/s geht aber. Ist aber nicht bei allen UM1s gleich. Viel Glück!

I never used the word "easy", I wrote "easier" which means something like "less difficult" without actually stating how much less difficult... :lol: No, seriously, I see your point... let me just think aloud... if the polygons (triangles in an STL, right? I'm absolutely no expert for the stl format) are sufficiently small, let's say much smaller than the deformations applied by the transformation function, straight polygons would be deformed in size but would stay straight in first approximation. Larger polygons however would have to be split up in sufficiently small polygons before transformation. There should be some good algorithms for this step used in e.g. FEM. If you think I'm writing bs, just let me know please. I can stand it... :smile:

Hallo scenic01 Zuerst mal herzlich willkommen im Ultimaker-Forum. Und da die Übersetzung von gr5 gar nicht so schlecht war, bekommen wir wohl auch bald noch die Bilder zu sehen, die Du vorbildlicherweise gleich gemacht hast. Ich bin gespannt darauf, denn wenige stellen die Einzelteile des UM selbst her und starten gleich mit einer modifizierten Version. So als erster, ziemlich blinder Schuss würde ich von der Beschreibung her entweder auf ein deutlich zu dick eingestelltes Filament tippen oder aber auf ein Problem mit dem Feeder. Wie hoch war denn die Drucktemperatur und die Geschwindigkeit?