gr5

First load the PLA setting. Then go CUSTOMIZE. Then change the values, then SAVE, then select PLA. This last step, if not done, means your save step didn't complete. You probably need the bleeding edge latest firmware for all this to work. For me it's flaky - if you create more than two custom profiles there is a bug also. I'm not sure how to delete them. But it usually works even without me doing anything with the LED settings.

This is partly solved. When I power on my UM2, lights and software comes on but the head won't home, no extruders move, and no heat comes on. The problem is with K1 - it's not closing. If I give the controller board a hard rap with my finger, the relay closes and the UM2 is fine until the next time I power it up. I will look at K1 more carefully in the future (check solder joints etc.) but right now I am printing something.

I still think you are printing too fast. But also the retraction speed is different in the UM1 I'm sure. What was the retraction speeds for the ulticode method versus the Cura-sets-retraction speed method. It's possible your retraction speed is too fast although I have been using the max - 35mm/sec on every print.

>By the way i was wondering how many UM2 are you producing and sending every week? I don't know this but I'm pretty sure the number dwarfs the quantity of people posting in this topic. I've seen a single day's shipment of ultimakers fill a DHL truck (or maybe it's more than one truck).

Interesting thought. Well - one thought - if you do it by height then when you change the layer height it you don't have to change it in the plugin. A small consolation I suppose. Maybe someone will write a plugin that does that. The layers are in comments in the code which in theory could change in a future version of Cura whereas the Z height is not in comments as it is part of the actual gcode that controls the printer.

Both the stepper drivers and the 12V regulator get very hot and will self destruct if you don't actively cool them. You can add a heat sink the the 12V part or buy a switching regulator part the plugs right in the same spot. But the stepper drivers will still get very hot. I think if you check the 12V regulator it's probably well above boiling temp (100C). It's the part you are supposed to lift off the board into the cooling fan. Of course if you print in an environment that is well below 0C you might be okay. Anyway I don't think any of that has anything to do with your current problem.

I have (a few times) aborted a print, figured out where exactly it aborted, removed the start of the gcode, added a G92 to set the extruder position properly and continued a print where it left off. It's a pain though. Only worth while if it will save you at least an hour of printing.

I doubt it. Be aware that the layers in Cura start at 1 but in the gcode start at 0 so they are always "off by one". Be aware that it will pause the first time the layer height is greater or equal to the height you specify. If you print 2 objects "one at a time" a well written "pauseAt" plugins will pause both time you pass through the Z threshold but I think the one posted on the wiki might not have this feature. Certainly there is a "tweakAtZ" that will tweak both times you pass through the Z threshold.

Go to Machine settings. Do you have "machine center 0,0" checked? It should not be checked. This would explain the problem potentially. If not that then I have 3 theories but none of them quite seem to fit the data. Basically tighten all your set screws. But more likely this is a Cura thing and not a "set screw" thing.

It happens on both. But the photo is of a UM2 which is doing a 36 hour (maybe much longer - maybe 48 hour?) print.

When I was printing a V shaped part where the middle of the V was filled in, I got this. The overhang of the V arms I assumed were shrinking and pulling/rotating at the base of the V and causing this problem. But I like foehnsturms explanation much better now. The PLA doesn't want to come out in a perfect rectangular stripe of filament. It would rather be skinnier and thicker but normally the head is pushing down on the part slightly so it flows into the proper rectangular shape. But if the part isn't well supported it bends and lets the PLA be every so slightly thicker than desired (maybe 5%). So you get .105mm of filament where you expected a height of .100. This adds up over a few layers and eventually the pressure is enough for everything to equalize but it means you have these "raised edges". Sometimes the head hits these and knocks over a part. To lower the pressure one might do better with thicker layers as you might need less pressure to spread out a layer of PLA. Or maybe underextruding by 5% will help. I really don't know the solution. Yet.

This explanation (plus the overextrusion explanation) both make sense. I've been using 6mm diameter supports in meshmixer - partly for this very reason. Interesting. The lack of fan may have made no difference because I got to a different section of the print then where parts "came together". I'm going to lower the temp from 220 to 210 to hopefully underextrude a bit. I want to set up a full scale test at some point but right now I'm in a multi-day print. I guess I could test on the UM1 but I am "working" right now. So maybe tonight.

Maybe I should reduce flow to 90% for a few minutes?

It's always overextruding on the lip because the lip is sticking up. But the plastic ends up going somewhere and it should fix itself after a few layers. I guess maybe because the part bends a little - that must have something to do with it - it bends down and then the nozzle leaves and when it comes back it's stuck up even further. So I can see how it doesn't correct too quickly but it seems like it should still self correct after a few layers.

Oh - and before anyone mentions it: I have bed at 70C, head 220C, this is about 20mm off the bottom. This print is huge - this is a tiny area of the print. Each layer takes several minutes to print so by the time the print head comes back to one of these shapes the part has had a few minutes to cool. Fan was on but I just turned it off to see if this makes it better or worse. edit: with fan off it seems better. We shall see...

Okay - I've seen this since I first started making prints - an overhang edge lifts too high and potentially the print head hits it and knocks it over. The worst ever was when I printed a propeller which was very difficult to print because of this but I prevailed and got a very nice print eventually. Anyway I always thought it was caused due to shrinking sides pulling and rotating the overhang upwards. But that theory makes no sense with this print. Every shape you see is identical to the layer below but shifted. The problem is occuring as usual on the leading edge of overhangs. This is very zoomed in by the way, these are .1mm layers. I've seen this on many of my own prints and also on other people's prints. Can someone explain what causes this and how do you fix this? If this print fails I'm going to set up an experiment and play with fan/temp/etc. But meanwhile - does anyone have a theory as to why the edge hanging over space would stick *up* instead of droop down? You might want to skip right to post #37 where we all started figuring out finally what is really going on!

No it does. As soon as you dial the new temp it starts changing temp. Even before you "set it" by clicking. But it's true that it won't print until you exit tune.

It is true that there are at least 3 people who have problems with clogging heads. There are probably at least 100 who have never experienced any. There just isn't much data out there on how much of a problem this is. This is a problem with many 3D printers unfortunately and the UM2 is very well designed to minimize this. Two of those 3 people seem to have finally solved their problem. In completely different ways (one had a problem with a teflon piece that had melted slightly, the other didn't have his bowden tube situated firmly enough). 3D printers unfortunately are not at the level of plug and play as say an HP inkjet printer. Check out the makerbot community if you want to see unhappy customers. But I think the UM1 and UM2 are a good product for the price. I'm sure in 10 years they will be considered junk.

That clicker is called a "limit switch". It detects when you have "hit the limit". I think Zax correctly identified the problem (but I'm not certain) - it appears to be a bug in the firmware if you cut power during homing. Hopefully Daid will fix this some day.

There are a few bugs related to the filament settings where they get corrupt, and changing the filament settings. I know Daid fixed one of them very recently. I recommend you get the latest Cura either now, or wait until the next one comes out (not sure if the fix is available yet) and then upgrade your Marlin. Until it's fixed, just do it on the tune menu.

The nozzle diameter is .4mm and that restricts your "resolution" more than anything else. The Z resolution is fantastic - you can get down to .05mm without too much trouble. So sometimes things are printed "on their side" to increase resolution at least in one axis. So back to the .4mm - diameter - that's actually a .2mm radius so if for example you print a square in the XY plane the corners will have a radius of .2mm. This is by far the limiting factor. Some people have bought/built .25mm nozzles (you can by them cheap). The problem however is that it prints much slower and gets jammed more easily. But I've seen fantastic results. Things like ringing in the photo above are easy to remove - just lower your acceleration. Basically speed and quality are a constant tradeoff. If you are patient and don't mind printing for several days you can get pretty amazing quality.

Basically if you hear the extruder clicking back/slipping/losing steps - rather than reduce flow, instead reduce feedrate.

With thick .2 layers you really need to print a bit slower. I think 50mm/sec is pushing it (60mm/sec is too fast I think) for a UM2. Try 30 or 40mm/sec - this should reduce the underextrusion. If you were doing .1mm layers then 60mm/sec is fine!

Robert speaks truth but more details: >That change is only temporary and only effects the current print. It's worse - it might only affect the current layer if you are below the 5mm (or whatever it's set to) threshold because any fan commands in the gcode will override your manual setting until you set it again. And each layer has a slightly different fan speed until you get to the "full" speed (whatever it is set to in Cura). I believe the whole point for this feature is that for the UM2 the fans were bouncing air off the heated bed and cooling the nozzle too much resulting in underextrusion on the lower levels. I could be wrong about this. What is the fan good for anyway? With very large prints that take a minute per layer you probably have zero need for it. For small things where a layer takes only 10 seconds or less it is important to cool the layer below before you add the next layer. It also seems to help bridging and unsupported overhangs as you want the filament to cool almost instantly as you are laying it down sideways in thin air. It helps immensely fight "pillowing" which happens on the top layer after covering infill on layers below. Similar to the bridging issue.

By the way avi, if you are planning to print very small, very precise details, at some point you might want to get a smaller nozzle diameter. It sounds like you might have the equipment to make your own nozzles. Some people have printed with .25mm nozzles and you get much better detail but they print much slower - the volume of nozzle is going to be related to the square of the change in diameter so .4mm to .25 will have a max print speed 2.56X slower. Another disadvantage of .25mm nozzles is they clog much more easily. I have a .65mm nozzle and love it. But I switch back and forth depending what I print and how much patience I have.