gr5

I would have predicted same quantity of clicks but since everything is slower it would happen less often in a given minute. But swordriff experienced something different. You're going to have to experiment yourself some time I guess. The UM2 is new for all of us and it is making the "clicks" more obvious so we are learning new things about under extrusion.

Don't know but someone else might: 1) Turn off your machine. With the power off try pushing the head back and forth in Y direction. It's safe to do this even when powered on but easier when the servos are off. Does it make the same noise? Or a similar noise? 2) Please take a short (10 second?) video of the issue so everyone can hear it.

Illuminarti - if for example flow is at 200% and you print something normal, you are likely to get those kick backs no matter how slow you go.

I believe you. This is possible and makes sense only if flow is too high or if cura is extruding for more than a .4mm nozzle (1mm in your case which is like 250% flow). But when spiralize is off and flow is close to 100%, you actually get less "jumping back" with lower speeds (or higher temperatures). Decreasing feed rate slows down all 4 Axes: X,Y,Z, and E. So it slows down the E, or extruder as well as X,Y. This in theory shouldn't reduce the "jumping back" except that the problem that causes "jumping back" in normal prints is that the pressure in the nozzle gets too high and the nozzle can only extrude a certain amount of PLA in a given time. I have to admit though that the "jumping back" feature of the UM2 extruder is still new for me and I've only been using it for a few weeks and I'm still learning much that was not so obvious on the UM1. When the UM1 under-extrudes it is not so obvious! The jumping back is instant feedback that something is wrong. Did you seem my curve that showed speed versus temperature on the UM2 that finds the limit where it does the "jumping back"? http://umforum.ultimaker.com/index.php?/topic/3418-um2-extrusion-rates/ I think I will have to completely rewrite that post some day as I've learned some new things since then but overall I think it is still useful.

Thanks for the post. If the extruder is making the "chuff" noise and slipping backwards, you should instead slow down the print. The nozzle can only extrude a certain amount of PLA per second. If you are getting the "chuff" sound you can fix this by either slowing down the printing, or raising the temperature (but that might cause other problems) or print thinner layers (less plastic per second). Decreasing flow is usually not a good idea but I'm sure it worked for you! Still if you could print at 100% and print slower you might get a better result. HOWEVER I also note you have spiralize checked and you have the shell thickness set to 1. This causes a similar setting as if you set the material flow to 1mm/.4mm or 250%. So setting material flow to 40% then brings this back to a .4mm bead with 100% flow. What you posted makes sense and it will work but it's a little strange to set the thickness such that flow is 250% and then compensate by setting flow to 52%. You could have just set the wall width to .52 instead. I think it's a little easier to understand if you keep the wall at .4mm or you keep the flow at 100% and only change one of these parameters at a time - not both at once.

Not really. The nozzle and the heater block are a single piece in the um2 and you have to remove the heater and the thermocouple - both of which can potentially be stuck and either could be damaged if removed too roughly. However your UM2 is still new and they might come out easy. Much easier to do is to take the head all apart and clean out the hot end from the "top". I suggest you order some acupuncture needles now so you will have one for the next time.

If when printing so much PLA is leaking out that it is dripping onto your print, then you can either add plumbers teflon tape in the threads or you can tighten things more. But my aluminum block rotates a little bit (hits one of the 4 big vertical screws though).

Yes it's fine. Make sure it can't rotate enough to touch the fan shroud as it will melt. If it *does* melt then repair it with kapton tape which can go up to something like 600C I think?

Some parts are too delicate to use a sharp blade. For those one needs a dremel. But it will melt the PLA unfortunately. So it is difficult but better than a blade.

If the gears don't have to *look* good but they need to function perfectly you can probably print very fast - say 150mm/sec and hot, say 240C. If you want them to look perfect you should print very slow, say 20mm/sec and cooler, maybe 200C. If you care about function over look, then you can usually print quite fast.

1) Look at the model in Cura "xray" view. If there are any red spots at all, cura considers that a problem. 2) If it's going to be a lot of work in your cad software to "fix" all the red areas (internal walls) then consider using the "fix horrible" settings. There are 4 checkboxes but you only have to try 11 combinations because A and B on at the same time is meaningless. 3) Also you may have an opening maybe? Somewhere on this level where the gap is? Or maybe your window panes don't connedt to the window frames. If you are going to try all 11, I recommend slicing very very thick (like .4mm or whatever the max is) so you can try them all quickly.

no. Please post a much larger version of the picture above. And also where did you get this PLA?

windows or mac? When you plug it in you should hear a noise (bung bung) in windows. Then go to "device manager" and you should see a new com port called "arduino" e.g. COM3. If this doesn't work, check for an unknown USB device. If you have an unknown usb device, unplug the UM. If unknown device goes away then you need to install the usb serial driver. Once that works, connecting is easy with Cura. You can specify the com port and baud rate. I strongly suggest you get the newest Cura (which also includes the usb-com driver): http://software.ultimaker.com/

Those parameters seem okay. Pushing it a bit but it should be fine. I still like the tangling hypothesis. Or temporary clogs. Is this a dusty environment? Someone recently found that the clip that holds the bowden down on the extruder (which has blades in it) was shaving tiny pieces of clear bowden tube and they were getting transported along with the PLA and causing nozzle clogs. But your problem only seems to last a layer or two. I would certainly go to .2mm layers *or* 50mm/sec (not both) which will put less strain on the feeder. Just to see if it helps. But normally 240C, 80mm/sec, .24mm layers should be okay.

I see you have retraction on now. Good. But I can't see much else. How did the object come out? Any better? A tiny bit better? Check out this test I did: http://umforum.ultimaker.com/index.php?/topic/1872-some-calibration-photographs/ That was 20mm/sec. Every PLA color and brand is different. What was your speed?

This is definitely under extrusion and it is probably on the inner layer as well. I like the many theories above. The most likely is the spool got stuck or tangled. But you may have gotten a partial clog due to dust or you many have been printing too fast/cold. What was your printing temperature, layer height and speed? (that's all I need to know). It could also be a slicer issue but this is less likely.

Yes. This is it exactly.

230C is definitely not too hot. Sometimes I print at 240C. If you are getting *any* clicking/extruder slip back then you need to slow things down some more. Here is a test I did with the UM2 but it is for an open nozzle - not one pressed close to a part being printed: http://umforum.ultimaker.com/index.php?/topic/3418-um2-extrusion-rates/ Since the time I did the above testing I noticed that sometimes the extruder misses steps but without sliding back (clicking). That's harder to spot/notice/detect. It was doing it on nylon so maybe it only does the silent skip with nylon.

My belts are quite loose and I get great results. No visible backlash or play in my prints. More importantly you could test the pull strength of your extruder. It should be able to pull filament with 22 pounds of force (assuming no additional load in the print head). Also you could load pronterface and experiment with different values of acceleration. I doubled my Z acceleration and that helps with the Z seam and makes changing layers more of a "click" now as it's much faster.

In addition to nick's advice, if you are printing something that has a surface area similar to the same size of the nozzle then you have the problem that the nozzle is pretty much contacting the entire top layer and so the top layer doesn't have a chance to cool. For parts this small it helps to print 2 or 3 of them at the same time so that each part has time to cool while you are printing the other(s).

in IMG7567 it looks like you have some serious under extrusion. Check to make sure your roll of PLA isn't tangling. This is common on a new roll especially on the Ultimaker 2. Higher temperatures give you better adhesion but I really don't think this is a temperature issue - it looks like underextrusion. This can be caused by plugs/dust, or by printing too fast, or by nozzle too cold, or defective extruder, but I'm thinking tangling is the most likely.

Hassan!! You have retraction off!! no wonder! I see it in your screen shot!

1) Yes, first layer too high 2) Use the brim feature. I see you used it for the pencil case but not the wrench. 3) Please do the following experiment: Get a thin piece of pla - maybe from a failed print that is only a few layers thick. Thicker than 3mm is too thick. In fact if you can get 5 or 10 or 20 that is better. Place it(them) on the heated bed and heat to 60C. After 5 minutes go back to the printer and remove the PLA part from the glass. Try bending it quickly before it cools down. Repeat at 70C and 80C. Try to find the temperature where the PLA is very soft. You want the bed hot enough to achieve this - you want the PLA soft enough so that even if it does warp a little at least it won't pull of the bed - it will just self adjust. Also you want the fan on a low setting for quite a few layers so the PLA doesn't cool below this "glass transition" temp. My blue PLA seems to transition around 55C.

I can't see the pictures you posted. Also, did you read my previous post? Did you change all those settings in my previous post? Eliminating stringing is tricky but possible. The key is to keep everything as cold as possible and make sure retraction is working. Look at the extruder motor. Learn to hear the sound of retraction. Then make sure it retracts every time and watch the filament at the top of the tube. It should go from the top of the tube to the bottom but no farther! This halts the pressure in the nozzle. Also some filaments work better than others. I have found white to be difficult but I have still gotten white PLA to work.

I'm kind of guessing here. But when you have a team/factory assembling Ultimaker2's and one part stops arriving because it is defective, and you order a whole bunch of that part (the belts). I assume you can keep going with assembly so that when the belts arrive it is a quick step to attach the belts to all the UM2's that are ready for belts. Of course you still have to test the printer at this point, but no "man hours" are wasted - it delays a week or two worth of orders but not the order's "farther out" in time. You can even pre-test that the electronics at least light up the display. This all assumes you have the space to store an extra 2 weeks of UM2's somewhere!