Nicolinux

From my experience this is due to the heating algorithm for the heated bed. Try and print the same object with the heated bed turned off (temperature 0°). I am pretty sure you'll see a big improvement... Use plently of glue stick to make it stick (maybe also add brim).

Wenn du Zugriff auf den anderen UM2 hast, dann tausche einmal das Board und probiere es wieder. Ich wette es liegt daran. Und sag bescheid bitte.

Just a little info on that. I've printed with 1.75mm on the UM2 (experimental Olsson Block) and the was no under extrusion, even at weird angles. I think this is an inherent problem of 2.85mm filament. It is just too stiff.

Simon, Just to check the basics, could you post a closeup picture of the UM2 head? Also check the feeder at the back of the machine. Maybe, after many hours of printing, the feeder is full of filament debris and so the new filament has trouble passing through. Then inspect your bowden tube for any big/ugly scratches (can happen if you pull out the filament that formed a plug). Take a look at the marks on the filament where the knurled mantle of the feeder turns. Does it grind down the filament there when you experience under extrusion? Sometimes there are some odd circumstances where a clean looking nozzle simply won't let filament pass through. Even if you take the nozzle off and you can look through the tip, there could be some gunk stuck to the inner walls. I borrowed a heat gun from a friend and I am using it to clean up the nozzles (using the Olsson Block here and it is great). I think a heat gun is way better then burning the nozzle with a Bunsen burner.

OctoPrint, Raspberry Pi, Raspberry Pi Camera Module. If you ditch UltiGcode in Cura you can use OctoPrint to controll your UM2 and print/archive the .gcode files.

Ok, here is an idea. Access the expert settings in Cura and untick "solid infill top/bottom". Then you can set the infill to controll the raster density.

Ok, here is another idea. Check (somehow) that your temperature sensor sends proper values. I'd imagine that it would lead to the problems you describe if the printer tries to extrude filament and thinks he has the right temperature even if that is not the case.

Usually this should be no problem as this is the standard procedure for most UM2 (that is if they updated their firmware). I guess your problem is the teflon coupler that is deformed and needs to be inspected/replaced. Usually you'd have problems with under extrusion too when the coupler is deformed allowing the filament to expand creating a "plug".

Hey guys, Any news on the new hardened nozzles? I have a huge project to print in XT-CF20 and the steel nozzle is troublesome. Now would be a good time to release the awesomeness... just sayin'

Check out page 64 of the assembly manual: https://github.com/Ultimaker/Ultimaker2/blob/master/um2%20assembly%20manual%20V1.1%20_english.pdf But I'd say, the nozzle could be saved with a heat gun. Just make sure you melt it

Alright, will try. thx

Well my problem is not so much the stuff that I have to trim away, but rather the weak inter-layer bonding. Have any of you experienced this problem?

Getting close, but not there yet. As I've said, thanks to 3DLac the prints now stick to the bed. But they are not sturdy and break easily along the x/y plane (layer). Seems like the inter-layer adhesion is off. I have two huge rolls of XT-CF20 here and when I started experimenting with it, I wanted to print this spool holder: http://www.thingiverse.com/thing:767737 The sturdiest print I've got so far was with a 0.8mm nozzle and the following settings: layer height: 0.4 shell thickness: 1.6 bottom/top: 1.2 infill: 30 speed: 30 initial layer thickness: 1.6 This print is ugly, but very sturdy. There were lots of filament strands that I needed to trim off (retraction is an issue - too much and you get under extrusion, too little and it looks like it needs a shave). But since I can't keep using brass nozzles because I don't want to loose longer prints due to nozzle failure, I started tinkering with the 0.4mm steel nozzle again. Always printing at 260° and without fans or else the temp error kicks in because the heater can't keep up. Print settings: layer height: 0.3 shell thickness: 1.6 bottom/top: 1.2 infill: 100 speed: 25 initial layer thickness: 0.3 initial layer line width: 120(%) Looks better and there is barely a need to trim stuff off. But, there is always a but... It breaks easily along the x/y axis. Keep in mind that it was printed at 100% infill. No way that would have happened with PLA. Even if those "ears" are the predetermined breaking points, I'd expect XT-CF20 to at least perform like PLA (if not better) in this regard. That's why I think there is still something fishy.

The bed adherence problem is no more! This 3DLac stuff is awesome. I'll try your solution when I run out of it. http://www.ebay.de/itm/3DLac-Spruhkleber-Haftspray-Einfuhrungsangebot-/321841529662 I tried printing at lower temperatures (with a brass nozzle and steel) but there was under extrusion. Even at 260° (with the steel nozzle) I've had a ruined print because of it. I'll post some pics soon.

The thinner filament is easier to handle. I've had some experience with a Delta printer where the extruder was able to pull the filament no matter what (even if the roll was just sitting on the floor or was tangled). It always worked and there was no skipping or under extrusion. Also 3mm filament is stiff and stubborn. 1.75mm isn't likely to poke your eye out

Ok, nicht schlecht. Berichte mal wie die Druckqualität ist, wenn du so weit bist.

Yes I was about to order the 35W heater. But I didn't think about the firmware... What do I need to do? Somehow I managed all these years to not have to build my own UM2 firmware

@exteban-pacheco: I will. In the mean time, here is something new. I am experimenting with colorFabb XT-CF20 and while printing with a 0.8mm nozzle, it got so full of filament on the outside that I had to pause the print and wipe the nozzle clean. Check this out: Right before I paused the print, the filament strands did touch. Then after the pause they didn't and after a while they touched again. Now the standard pausing procedure on the UM2 is to retract some filament and move the nozzle to the front left while holding the temperature (fan was off for that print). When the print is resumed, it would extrude some filament first and then continue the print. However, there is some oozing involved and even with the extruding right before resuming the print, some filament is "lost". I guess this reinforces the theory that this issue is strongly related to under extrusion because "losing" filament is the same as "not enough filament extruded".

Here's a little update. Increasing the flow did not have a big impact, but increasing the "Initial layer line width" helped because the extruded strands of filament are much wider thus allowing for more surface to stick to the bed. XT-CF20 still barely sticks, but at least I've got some successful prints at last. I have also ordered 3DLac and will try that too. I have tried different nozzles (the 0.8mm one is fun to watch... looks like toothpaste smeared on the heated bed ) but I will stick to the stainless steel one for now because I have a huge project to print in XT-CF20. I could use brass nozzles until they degrade but then I'd have bad prints if the nozzle decides to fail mid-print. But now something else came up. No matter what nozzle I use (steel or brass), I can't print with fans on because the heater can't catch up quickly enough with the difference in temperature and the temp error kicks in. I guess the heater is not strong enough to keep the temperature at 260° no matter what. I tried different "Fan full on at height" settings, but without success so far. Anybody else had this problem?

Nein die Annahme ist nicht falsch aber der Extended wurde nach dem normalen UM2 veröffentlich, Zeit genug damit Verbesserungen die in der Zwischenzeit aufgekommen sind, zu erhalten.

Hi, schau mal im Ultimaker-Shop rein. Dort müsstest du die meisten Teile finden: https://shop.ultimaker.com/5/Spare-parts

Thanks guys, I now have some success. I switched to a brass nozzle (even if it will break after a while). I have also increased the first layer height. It sticks better now, although at some points it just won't. I suspect that my heated bed is not entierly flat. Slowing the first layer is a good idea too. Gijs from colorFabb also suggested to increase flow to too. I'll try both and report back.

Hi, I am trying to print with XT-CF20 but I can't make it stick to the bed. For the nozzle I tried temp. ranges from 250° to 260°. For the heated bed 70° to 75°. I have (over)used the glue stick to no avail. One thing I learned - the bed leveling is key. So I leveled the bed/nozzle to be really really close to each other but still no luck. Also tried tampering with the leveling mid-print. There is a sweet spot somewhere but if I get it to stick at one far end, the filament deataches itself at the front (or somewhere else). I am using the Olsson Block with an stainless nozzle (0.4mm). I have uploaded a video: Do you have any ideas?

I have the Olsson Block and the issue is still there. I've also changed the temperature sensor and fan shroud. The next thing would be to swap boards but my motivation is kinda low.

Hi, das liegt daran dass der UM2 sog. Profile für diese Einstellungen direkt auf dem Drucker verwaltet. Schau dir den Menüpunkt "Material" -> "Settings" an. Dort wählst du aus mit welchen Filament-Einstellungen du drucken möchtest. Neben den vorhandenen Profilen wie PLA und ABS, kannst du auch eigene erstellen. Einfach auf "Customize" gehen und dann die Werte verändern. Danach auf "Store" (oder so) und enweder ein vorhandenes Profile auswählen zum überschreiben oder als neues Profil. Das neue Profil heisst "Custom 2", "Custom 3" usw. Es gibt noch die Möglichkeit eine .txt Datei anzulegen auf der SDKarte und dort die Profile umzubenennen und zu verwalten. Aber das war mir auch zu fancy und ich habe es nicht benutzt. Ich denke Ultimaker wird sich bald von diesen Profile verabschiden in dieser Form. Sie sind zwar praktisch weil du damit einen Objekt nur einmal slicen musst, und dann mit mehreren Filament-Sorten drucken kannst - aber in der Praxis kommt das eher seltener vor. Es gibt zudem noch die Möglicheit in Cura die "GCode-Flavor" umzustellen auf "RepRap/Marlin". Dann werden die Profile nicht mehr beachtet und du kriegst in Cura weitere Eingabefelder für Filamentdurchmesser usw. Aber dann verlierst du z.B. den Startup-Vorgang beim Aufheizen der Düse. Das ist momentan relativ ausgeklügelt und nützlich (zu erst wird das Heizbett aufgeheizt, dann die Düse, dann wird etwas Filament ausgespuckt damit es an der linken Ecke hängen bleibt und nicht an der Nozzle klebt und die erste Schicht ruiniert).