tomnagel

Several testprints are made with every printer that leaves the factory, and one of them is in your styrofoam packaging (dual color piece). The metal shaft is supposed to be clicked in the black sliderblock. Feel free to click it in. Seems to me your printer had a rough ride on its way to you. How did the box look like? How much do you want to do yourself to get the printer running? I have some tips for you. The front fan bracket should be hinged on the back of the printhead. Is the bracket attached to the hinge points? Secondly, the front fan bracket may be bent a little. See this illustration. You may carefully bend your bracket slightly to get it to click right. Of course, you have every right to not do this and ask your reseller for support. You paid for a premium product, and I'm sorry to hear it did not arrive right.

SunnyB, you mention that you run into problems with PVA printing. Can you describe the problems that you see? Pictures help a lot! Some tips in advance: 1) Use Cura, and no other slicer, to print PVA. At least until you know what you are doing. 2) Use the default quality profiles that come with Cura. Don't mess around with settings that are under "advanced" until you have made good prints with the defaults. 3) Use Ultimaker materials. The quality printing profiles in Cura have been adjusted to Ultimaker filaments. 4) Watch ambient temperature and humidity. PVA prints unreliable at higher temperatures and humidities. Stay below 28 degC and 55% RH. If you want any extra help, please post what slicer, settings and material you are using. Good luck! Oh, about the cold pulls: the elongated one might be caused by pulling at a too high temperature. At what temperature did you pull?

Are you already up and running?

Results with Ultimaker PLA and PVA are amazing. Really. It is vital to use the quality profiles that come with Cura. Don't play around with the settings until you have gotten good results with the default profiles. Yesterday I have been busy making spare parts for a marble track. The part is pretty small, 25*13*12mm. The shape of this part makes it impossible to print without support. Perfect job for my UM3, with PVA support. The next picture shows layer 51, which is about halfway in the part. You see the PVA structure. A few layers later (layer59) , the PVA gets a roof, where the PLA will sit on: And in layer 60, you see the PLA is deposited on the PVA: In reality, this looks like this: In the final picture, you see on the left side 1 layer of PLA on the PVA, and on the right already 2 layers have been deposited. As stated above by ultiarjan, the horizontal expansion feature is crucial. But you get that automatically when using the default. To save a little bit of printing time, I set horizontal expansion to 0 one time, resulting in a print I had to stop halfway

If the right nozzle is not lifted when the left nozzle is printing, you may need to recalibrate the switching bay location. Head to system->maintenance->diagnosis and run the switching test. Look whether or not the nozzle is lifting. If not, you can calibrate the switching bay location in system->maintenance->calibration. During this procedure, the printer asks you to move the print head such that the lever on the right side of the printhead is in the switching bay, on the right side of your printer. After that, the printer switches the right nozzle up and down, for verification.

That is not how a good print with PVA should look like. Below a humidity of 55% the Ultimaker PVA stays ok to print with for months. Above that, reliability problems start to occur. So indeed, keep an eye on ambient conditions. Furthermore, if you have had an incident with PVA, please clean the BB nozzle according to the instructions. Although it may be extruding when you push the filament by hand, my experience is that it is not easy to determine whether or not the nozzle is clean. When in doubt, clean it. Oh and last but not least: start with using the default quality profiles. A lot of time have gone into these, the settings are really good. Only start experimenting with settings after you have become familiar with the printer and the new materials.

The quality profiles from Cura 2.3 should work very reliably with the UM3 and UM PLA. Did you use the so called "recommended" mode (in slightly older version it was called "simple mode")? What's the history of your printer? Have you had an incident where the printer has been "air printing" for a long time? In that case your hot end might be clogged, and you have to clean it (see UM website for instructions).

* There is some difference in adhesion between the 2 sides of the glass (it's not coated or treated or anything, but it has to do with the way the glass is produced). You can try to flip your build plate. * I'm curious to see the video you posted above, but "the video is marked as private" * Could you make a close up of the brim? I think the brim will tell whether or not the distance between your bed and your nozzle is ok.

Have you checked your pulleys (all tightened?) or your short belts (not loose)? What I see in your picture reminds me of what is described in the troubleshooting guide of 3Dverkstan under "Circles not round / Lines not touching"

Both issues mentioned here are on the backlog. Not scheduled yet, however, so no promises.

Experience in Ultimaker R&D is that PVA stays fine for months when humidity stays in "normal office conditions". Let's say 20-25degC, up to 55% RH. This holds for Ultimaker PVA, other PVA's we have tested are much more sensitive to moisture! Here in the Netherlands in summer, sometimes humidity goes above 55%, and temperatures sometimes rise to 30degC or even hotter. The reliability of printing PVA then drops to unacceptable levels: too many prints fail. Cause for failures is that the filament gets too soft for the feeder. The statement that PVA gets brittle with moisture is opposite to our experience. Both temperature and moisture make PVA soft.

Nylon and PLA can be combined with PVA as support material. Other combinations are not officially supported. But feel free to experiment!

The combination ABS and PVA will not work reliably. The 2 materials simply don't stick well enough to each other, even if you would manage to stick both to your build plate. Ofcourse in some cases you can get it to work. For example, if you need to support a piece of overhang, which is connected to the rest of the object. But if a piece of the object needs a start on the PVA, you have to have a build material that sticks well to PVA. And ABS does not do that.

Why would you combine PVA with BuildTak? PVA and PLA stick to glass just fine.

You can put your PVA spool on the heated bed at 55 degC for a few hours. That will drive out the moisture. If you use the PVA in a climate of RH<55%, then it stays in good shape. Above that, the chance of jams becomes higher, because the PVA becomes soft. Temperature has the same effect by the way, stay under 30 degrees. Don't trust the dial of your oven at such low temperatures, as it is probably not accurate. You may ruin your spool. Is your hotend in good shape? If you have had an incident where the hotend was hot when there was no flow (jam, end of roll, ...) the PVA will have transformed into a brown sugarlike substance that (partly) blocks your nozzle. see this page on the Ultimaker website to unclog your nozzle. Don't be afraid to use multiple hot-pulls before trying a cold pull.

The Active Leveling measurement procedure raises the bed until it detects hitting the nozzle. The first probe with each nozzle is done with a hot nozzle, so that the measurement stays fairly accurate even when there is ooze on the nozzle (result is better with a clean nozzle). So damage to the buildtak because the nozzle is hot is very well possible, but has not been researched by R&D (yet). You could of course disable Active Leveling, but my recommendation is to use materials which don't need BuildTak.

The Auto leveling has seen limited testing with BuildTak, tape and avery sheets. In those limited tests we saw no negative effects. If you need ABS in your application, try Ultimaker ABS. Bed adhesion is almost too good, that's why we tell users to use a glue stick. The glue forms a breaking layer, preventing chips of glass to break from your printbed! PLA and PVA should stick to your bed very well. Make sure the bed is clean!

Look for the file fdmprinter.def.json In that file, the default adhesion type is set to 'brim'. Most of the quality profiles for the UM3 do not contain a value for adhesion type, meaning that the default value in fdmprinter definition is used. (I think that only one nylon profile is set to 'raft'). So if you change that value to 'skirt', in almost all profiles a skirt is applied. For advanced users who do not mind spending some time in this: What you have to know is that all settings that are used for slicing may come from multiple definition and profile files. There's definitions for machines, extruders, nozzles, materials, quality etcetera. Currently, there is no way to know where your current setting is defined. It can even be defined in multiple files, so you have to know the hierarchy to know where to change it. I think there will be some documentation on this later on. What I recommend: use the default profiles. A lot of testing has gone into these, and they shoulp perform well in most cases.

My suspicion goes to the z-bearings. If you decouple the spindle from the bed, or at least the z-motor from the spindle, does the bed move smoothly? Without points where it feels like there's sand in the bearings? Such friction points in the z-bearings can hold the bed at a certain position while printing. It just hangs there for 2-3 layers, until the play between spindle and nut runs out, so that the bed is forced past this friction point. Since it then drops multiple layers, the next layer that is printed looks underextruded, and may cause separation as you describe.

I have set Vmax z to 24 instead of 10, and Amax z to 400. This is especially noticable in the 15mm z-move at the beginning of each print. I have yet to see whether it decreases the z-scar.

On the Ultimaker Original? That is interesting. Which values are you using?

I wish to decrease acceleration, to see the effect on the ringing artefact. Browsing through my UltiController Menu (on UMO), I see a parameter " Accel" on 3000, and a bit further down I see "Amax n" for n={x,y,z,e}. Values at 9000, 9000, 100, 10000. What is the meaning of the first "Accel" parameter, which is set at 3000?

I have a home made heated bed on an UM1. I use hardened glass, so I don't think the hot nozzle against the plate is a problem. I'll modify the startup lines to heat up the bed first. Related question; what does T0 mean in the line

Most of the time I print with a heated bed, which takes a few minutes to warm up. The GCode that is generated by Cura makes the printer warm up the bed and the nozzle at the same time. The nozzle is at setpoint within a minute, and starts oozing for a few minutes, because the bed is not ready yet. This causes a bad start of the print. The trick that I am doing manually is that I put the (glass) bed against the nozzle, so that it is closed. I do this when the nozzle is at the XY home position. This is important, otherwise the homing action of the printer after heating would drag the head accross the glass bed to the home position. Today, I thought that this simple trick (closing the nozzle with the glass bed) could be done automatically. This might be built into Cura. How do other folks handle the oozing of the nozzle during heating of the bed?

In Cura, I have a tab called "Start/End-GCode". If I compare the GCode that is generated by Cura with the lines on that tab, I notice there are some lines in the GCode even before the Startcode. I copied them both below. I want to do some actions with the printer before it starts warming up. Currently, this is not possible, because the lines in StartCode are executed AFTER the warming commands. Can I somehow influence these first few lines? Where do they come from? Below the actual GCode: And here is the StartCode: