gr5

I like Illuminarti's theory. A lot. It fits with what you see because Cura has the fan off for the first few layers and gradually turns the fan on (it also gradually speeds up the print). This part appears to have no stringing issues - meaning it appears that there isn't much retraction going on. So I would recomend a little more heat and a little less fan. Also since the part is nice and large you might be able to do without the fan. Can you turn fans off or run at 50%? Also raise temp to between 210C and 230C. Those two things (220C and less fan) will probably be enough.

Yay!!! :sad: Warping/shrinking is very complicated. If all you care about is the bottom layers this is very easy to fix. Assuming the part is the robot or larger and you are using the blue PLA that came with the UM2 then 70C bed temp is great. This will keep the lower layers of the robot hot enough that it never becomes solid and so it will be soft. It is also important to keep the fans off for the first 10mm or so. That way the entire lower portion of the robot stays above 55C and 55C is about where that ultimaker blue PLA turns from mush to solid. You can do this in cura advanced "cool" settings. It would be helpful to keep the air also hot so I would consider closing the front of the UM and covering the top with a box but this shouldn't be necessary. In addition, the "brim" feature in cura helps immensely. Also cleaning the glass (with soap and water or alcohol or windex or dish washing soap) and then a thin coat of glue stick. Make sure the glass plate cools to at least 50C before trying to remove the robot because at 55C or warmer you may destroy the robot (distort it). For ABS you need the glass MUCH hotter - I think around 110C maybe?

This seems unlikely but possible. Are you sure you aren't getting MINTEMP or MAXTEMP errors? Is this a um1 or um2? Search the gcode file for M104, M109. e.g. M104 S0 turns off the extruder heater. This is a common problem. The models have extra internal walls or holes in the walls. Experiment with the 4 checkboxes in the "check horrible" section. It's easy to try all 11 combinations of checkboxes to see if you can fix this. If not you have to look at the model in "xray view" instead of slice view and fix any red areas. But usually "fix horrible" can take care of it.

I mean that I can *usually* print on the UM original 190C and 50mm/sec but sometimes it under-extrudes. It's kind of on the edge. It will be minor under-extrusion and the part will be functional but ugly or it will have zero underextrusion and come out quite perfect it's just on the edge. But if all I care about is functionality then I print at 150mm/sec and 240C.

Well next time you are coming by Boston LePaul lets get together and fix your printer.

Well it isn't a problem on *every* UM2. For instance on my UM2 it just barely misses the clip and all is fine. So I think the first few UM2's that were built didn't have this issue. But not only does UM know about this problem - I saw a list of "bugs" they are fixing and this is on their short list.

Please encourage that person to translate to english. I only read the english pages and if you post a question in english you will get a fast response. There probably just aren't enough italian users yet that are nice enough and smart enough to answer all the questions yet. Most of them are probably not reading the forums and are enjoying their printer.

Other people have the same symptoms as you - they upgraded the UM firmware and now the green light comes on but not the front panel. For them the problem was that they loaded the UM1 Marlin firmware into the UM2. When you use the Cura wizard to upgrade the firmware you have to be very careful! You won't break anything but I suggest you re-load the firmware and be extra careful. For example you might want to use the expert menu - that way you can see the file names and choose one that says "um2".

I'm not sure what you mean. Are you clicking on print from the front panel or within cura. You should only be printing from the SD card. When you click print it shows a "progress bar". It doesn't print until the progress bar gets all the way to the right - this is because it is waiting to heat up. I'm not sure what you mean - but on my printer it also prints 2cm to the left.... from the center line. Is that what you mean? 3a: if the filament has retracted more than a little, then before you print, go to the advanced menu where you can extrude some filament until it gets back towards the head again. 3b: clicking is bad but not necessarily super bad. It means you will get underextrusion and not as good quality on your print. But you will still get an "okay" print. To reduce extruder clicking you must print either hotter or slower. Try raising to 240C or dropping your print speed in half. Just try it. You can do it while it is printing - change feedrate to 50% or change nozzle temp to a higher temp. This is a known bug. There's lots of posts about this. I think if you get the latest cura and re-install the firmware this is fixed. There are alternate fixes for now - one is to add a line that says simply "M25" to the end of your gcode file on the sd card before you print it. The bug has to do with Marlin not being able to read the last bit of the gcode including the part where it lowers the bed, turns off the heat. Another known bug. This wizard is for UM Original only. I suspect this will be fixed by ultimaker soon. They will either move the clips or somehow disable this wizard for the UM2. For now - just don't do it. In fact the only time you should ever connect to your UM2 with USB is to upgrade the firmware. Any other time is asking for trouble.

Richard - as Robert already mentioned - I already answered your question. Please read it again.

Nick is right on both counts. Stopping this leak by tightening is not easy. I think you have to do a complete disassembly. Either that or raise the 4 screws, remove heater and temp probe and rotate the whole aluminum block. But it needs to be well over 180C when you do this. Or you can take it apart and put teflon tape in all the threads - the problem isn't with the nozzle threads - it's higher up in the threaded brass tube. Another way to stop this leak is by printing with some abs for a few minutes and then switching back to pla. The ABS will leak out of the cracks, and then cook and boil and blacken and gum up and seal all those leaks. UM used to ship a meter of ABS with every machine and the purpose was to seal up the leaks. But be careful if you tighten with a wrench - brass is not very strong. Your other problem I agree is underextrusion. Try printing a little slower maybe. Or maybe tighten up the spring on your feeder. Or raise the temperature a little bit - maybe to 240C?

In the USA, printbl.com is excellent. I think it's a secret. But I'm pretty sure it is colorfabb.com. If you look on their web page and also on ultimaker web page you will see the spools that hold the filament are very similar.

The two side fans on the UM2 are hooked in series to 24V so they each receive 12V. Although if one shorts out the other will receive 24V. Also this means if one fails in the open state the other will shut off.

Yes, rotate the z screw by hand - you will need to clean the grease off your fingers afterwards. Also unplug the big powersupply until the blue light goes off (may be more than 5 minutes!) and then plug it back in. I think it might have a safety feature where once it detects an overload it stays off until a power reset.

Which version of Cura? In cura 13.11 go to "machine settings". I think maybe you have to check the box next to "Machine center 0,0". I think this might fix this: I don't know if Cura knows how to print the x3g format - I doubt it. I would stick to replicatorG for the final printing step after converting to x3g. The way Cura detects the baudrate and the way Cura detects if there is a printer is by sending a gcode and waiting for the response. So this will not work with an x3g format printer. So you should use cura *only* to slice and create the gcodes. Then convert to x3g (binary format). Then print with replicatorG.

OH! I thought he meant the first layer was rough. PICTURES PLEASE!

I don't know about replacements but you can peel back the paper and add a drop of oil. That will probably help greatly.

Oh - and when printing PLA and printing that slow you shouldn't have to mess with the flow.

Do you have a picture? um1 or um2? The first layer is very difficult to get perfect because having the bed flat *and* level is hard. I recommend the first layer be .3mm if you can. You need a first layer Z height accuracy of about 1/3 the height of the first layer. So if your first layer is .3mm then you need to level plus or minus .1mm error (the width of a sheet of paper). But if you print the first layer .05mm - well then you need accuracy of plus or minus about .02mm. That's pretty much impossible with the plastic bed as it has warps in it larger than that. So it just can't be done unless you have glass or MIC6 aluminum. Anyway you probably need to relevel after every print or at least once per day. Here is my levelling procedure for UM1: How to level: leveling here is defined as setting the Z height and also leveling. It's one procedure that does both at once. Optionally heat up the nozzle to 180C because a cold nozzle shrinks and you will be setting the bed to the wrong height. Make sure tip of nozzle doesn't have any plastic on it or you may level to the wrong height. I usually prefer to level with a cold nozzle but if you want extra accuracy then use hot nozzle. If you have a heated bed that should also be warm for the same reason. Home the z axis only. If you must home all 3 then you need to disable the steppers once it's done so you can move the print head by hand. Move the head as close as possible to each of the 4 screws in turn. Once at a screw tighten the screw and then slip a piece of paper between the nozzle and the print bed. Make sure the paper slides very freeley. Then loosen the screw until the paper gets slightly stuck. You want the paper to easily be able to slide in and out under the nozzle with one hand pushing the paper. If the paper gets stuck it's probably too tight under there. While levelling try rocking the bed across both opposite diagonals to see if one of the screws isn't touching the bed and to see if the bed is "hung up" or stuck on the threads of a screw instead of on the screw head. Repeat this procedure for the other 3 screws. Then go back to the first screw and repeat on all 4 screws again. Then repeat on all 4 screws again. Then again. It may take you 20 minutes to do this the first time but the second time you do this it should take much less time because you are both better at it, faster at it, and because there isn't much to adjust the second time. Note that the act of putting the screwdriver in the head can apply weight to the bed and change the height. You have to be careful to put as little weight as possible when testing with the paper. If you leveled with a cold nozzle you are done. If you leveled with a hot nozzle you should then loosen the 4 screws 1/8 of a turn to compensate for the thickness of the paper. Once done leveling rotate the z screw by hand to keep the nozzle off your bed. This makes it less likely to damage your bed surface and gives the nozzle room to leak. On a new ultimaker repeat this procedure before every print (at least every hour) because the print bed can move/droop like a new guitar string. After many months the droop slows down.

The head never leaves the top so the PLA never has a chance to cool enough to become solid. What temp were you printing at and were both side fans running? Assuming those settings are reasonable, the next trick is to print two of these at the same time - place two into cura and then under "machine settings" set the gantry height to zero which forces both prints to print simultaneously - that way each part has time to cool while it prints the other. Also make sure you don't have "support everywhere" turned on for this part. You can probably almost get by with zero support. Personally I would but a little support in the CAD model instead of letting Cura do it. Is there any chance you can lay it flat on it's back? Or is the back side as complicated as the front side?

The rear fan should always be on and it comes even before the lights. It should be quiet. What country do you live in? Illuminarti lives in USA and he found one quickly. It would be nice if you added your country to your profile settings.

It sounds like a fan. But it looks like the head fans are off. The 3rd fan should be on however. If you simply turn your printer off and then on, the 3rd, rear fan should come on and the axes should be loose. You should be able to grab the print head and push it around. See if you can duplicate the noise. If so see if it comes from that 3rd fan.

I got the impression from another posting that if you merely tighten the screws it fixes the problem (2/3 of my posts are just re-posting something I already read here - sometimes I feel that's all I offer - repeating what other's say).

All robots done by my on my UM2. To zoom in to above pictures, first click on a picture, then right click and choose "view image" then click again and it should be bigger than your monitor (1500 pixels wide). The robot on the left was done with the robot slice that came on the SD card so I don't know the settings. It involved a hot heated bed at 70C. The robots on the right were printed on blue tape on the glass. The blue tape was washed with isopropyl alcohol so the robots would stick well. They were printed at 205C at 20mm/sec and then lowered to 200C when the printer got to the support structure for the robot's hands. I don't remember if I did .1mm or .2mm layers. If you have 2 robots one printed .1 and one .2 you can count the layers on these robots' shoulders and figure it out.

You can definitely print the UM robot just fine on the UM2. I recommend re-slicing with Cura 13.11. Try printing slow. Try 40mm/sec or if you want flawless perfect quality go to 20mm/sec and 190C. But 214C at 40mm/sec should give you a large improvement. .2mm per layer is fine. .1mm per layer is fine also but will take longer. I'll post a picture in the next post...