gr5

Try a newer version of Cura - a bug that causes surface bumps was recently introduced that is fixed once again here: http://software.ultimaker.com/Cura_closed_beta/ Also 70mm/sec is fine for very large parts with long smooth moves, but with small tight curves like this you will improve quality quite a bit at 30mm/sec. Or even 20mm/sec. This is because the extruder isn't constantly speeding up and slowing down as it will never go below 10mm/sec (3 to 1 speed change ratio versus 7 to 1).

Also try slicing a small stl file just to see if it can slice *anything*. Try the smallest STL file you have. Preferably under 11k even though Cura can usually handle 1Mb STL files just fine. If it can't slice that then go to microsoft update and look for "optional" graphics driver updates. That solves *so many* problems.

win 7? Possibly graphics drivers. But then that would only crash in layer view I think? I don't know but there were some changes at 13.04 in the layer view display. Also there is a bug in 13.04 where it slices too many line segments even if they are only .00001mm long. So try reducing your polygons. How many millions of polygons do you have? Or try thicker layers - try 1mm layers just to see if it will slice. You can reduce polygon count with this technique (it worked well for me and meshlab is free): http://www.shapeways.com/blog/archives/226-polygon-count-reduction-with-meshlab.html

In general the screw should be mostly to spec but the nut hole will be a bit small. Probably around .5mm too small. Aside: .04mm might be too low -- I recommend .1mm layers as you will probably get better quality. There are 3 reasons why vertical holes are .5mm too small if you really want to know. And it varies by your own settings so it's best to just adjust the holes (or nuts in this case). So scale up that nut so that it is .5mm larger in the hole diameter. Even better get some calipers and measure the error exactly and scale up the nuts accordingly.

You can pay $100K for a printer and still won't necessarily work out of the box. No one makes a "3d printer" the way they make the "2d printers". The 2d printers are very complicated now. Even the ones they give away for free have all kinds of feedback sensors. They all have a camera to watch the paper loading and things like that. It should not be called "3d printing". It should be called "Additive Manufacturing". It's easier to use than a CNC milling lathe. But at least as hard as learning how to use a sewing machine. There's definitely a learning curve no matter who you buy from. For now. Wait until HP starts making millions of these every month. Then you will see some serious improvement. Having said all that the UM2 is a pretty awesome printer. I don't think you can get as good a printer for the money unless you get the UM1 kit and are willing to spend 20 hours assembling.

Hmm. Not with the gui drag/drop feature. I would combine all the STL's into one big STL file and slice that with cura - that way at least all the parts will be the exact correct seperation. Then I would probably do one of two things - in machine settings I believe cura centers your object on the center of the platform so you can adjust your X and Y max distance to cause Cura to place the objects properly. Or you can hand edit the gcode file with an offset. For example if you want to move X to the right 1mm and Y toward the back 2mm, after home do: G0 X1.0 Y2.0 G92 X0 Y0 That sets the x=1 y=2 position on your bed to the new 0,0 position.

Which allows other options like flame, heat gun, iron, steam, torch, soldering iron, angry bees...

By the way - when putting the head back together make sure the distance between isolator and isolator nut is as small as possible (about 1mm). This reduces the spring force on the isolator and reduces the friction and reduces some underextrusion issues.

Heating to 100C might be enough so you could use boiling water to loosen the "isolator nut" (that's what UM calls it). Although I recommend 180C. Once the white teflon part is out everything else (the metal parts) can handle 300C no problem. Regarding the thin screw with the allen hole on top - you can just use vice grips as damaging the upper threads shouldn't be a problem. Regarding paying UM for parts - I don't think they have a way of accepting payment other than for the stuff in their store. So they usually send you free parts even long after warranty is over and even if you admitted that it was your own fault that it broke. I think they are interviewing for more tech support positions but that takes time also. If you need a spare part and you are in the USA you can get special treatment - please update your location settings in your profile and if you are in the USA also send me a PM and I can hook you up with free replacement parts (nozzle and temp probe in this case).

Damn it. This changes everything. You didn't say it was only the first layer. That's a leveling issue. I can't tell if the head is too high off the bed or too low but I strongly suspect too high. It could be you have bent rods or something. In the gantry. Hopefully not. I know you said you leveled a few times. Here's what I recommend. 1) Assume nothing is wrong with the printer - level one more time but this is 3 point levelling and you don't level for the left rear directly - instead the rear screw and the front right screw control the back rear the most. If the front right screw is too high (too close, too tight on the paper) then the back left will be to loose. So make sure you have the *same amount* of friction on the paper as you slide it in and out. Try printing one more time. Also in Cura set your bottom layer to be .3mm thick (this is the default). There is a homing bug on some machines (will be fixed with software soon). To avoid the homing bug make sure the bed is not all the way down before levelling and again before printing. It needs to be at least 5mm off the bottom position. 2) If that doesn't work - assume (temporarily) that the rods are bent (or the glass?) and test for flatness. Look visually at the printer - does it sit flat on the table or rock on two corners? Look at rods and glass - does it seemed warped or bent? Probably not. To test for flatness more accurately install pronterface: http://koti.kapsi.fi/~kliment/printrun/ Connect computer with pronterface to the UM2. Tell the printer to go to Z=0 position. I think you can do it with the buttons or you can type command: G0 Z0 Even better go to .1mm up G0 Z0.1 Then push the head around with your hand to the 4 corners and check leveling with paper. See if there is a "low spot" in the back left corner but *not* a high spot in front right. If there is a low spot *and* a high spot you just didn't level it well enough so rotate those thumbscrews some more and get it perfect.

The white teflon piece is the "isolator" (that's what UM calls it). The "barrel adjuster" seems to be officially called the "isolator nut" (it has (6?) holes through it). The isolator nut is probably the most delicate thing in there as the walls are very very thin where it is threaded.

How do you change filament? Standard way or heating up and pulling the filament out? Standard way until about month ago. Now I heat up to 90C, pull damn hard with my hand and hand insert the new piece. I haven't used "change filament" in a while. Do you "sharpen" the filament tip so it doesn't get hung up inside the teflon piece? Now I have to as inserting by hand is a pain. I almost always cut the pla to a nice tip. Partly to discard the old tip. How often do you change filament? Every other print or so. I'm always changing colors. Do you let the nozzle heated up for a long time? Never. I'm afraid to let it stay hot very long at all. 240C is my max temp for the most part. Do you perform _very_ long prints? I've done 3 prints > 12 hours. One was about 30 hours. Room temperature where the printer is stored. UM says 20C. I have AC in summer, heat in winter. Never gets very humid. UM2 in the fall so haven't run AC yet. Wich filament do you use (spool, loose, brand)? Mostly UM but also printbl. I have had some underextrusion on spools down to the last 1/4. I now only run those spools on the UM original. Did you change motion settings? no. Did you increase stepper motor current? no. Do you use an alternative feeder? no. Haven't taken mine off yet or looked inside yet. Do you have a filament dust filter? Not really. Tried it - was a mess. Have you took the electronics cover off and checked where the extruder motor wires are guided? (maybe if they are guided wrong and are too close to other componentes, the extruder motor might be influenced during prints). My cover has been off for a very long time. The one thing I do that not many do - and I think it's important - I always print with filament on the floor. I think the feeder is too low and/or the filament spool too high and that creates a 45 degree angle as the filament enters the feeder. Other things: I've had many tangle problems. Now when I remove filament I hang on to the end and tuck it through a spool hole so it can't get tangled. I can't print 10mm^3/sec usually but I rarely need to go that fast - I mean I can print the cylinder to 10mm^3 but it isn't dependable - not safe. I feel comfortable printing 3mm^3/sec at 230C. I have 2 printers and I've never been able to keep them both going. So I'm really not in a rush, so I tend to print slow. When I push it to 5m^3/sec I'm bound to get a single ugly underextruded layer. I love the atomic bob method and so basically do it on all filament changes now. I have had at least 2 nozzle clogs that needed combination of atomic method and sometimes also some hypodermic needle.

Well fuh and I both lowered our spools and both had improved results. I have too many other tests in mind right now to do this one. Right now I'm experimenting with slicers and thin walls.

@andrew white - what country are you in and also please update your profile settings to indicate that country in your location field. The answer to your question depends on what country you are in as there are dozens (hundreds?) of suppliers of PLA alone.

So sumnivent, take a picture of the print head also so we can see where the bowden tube ends.

Yeah - what I was going to say. Also make sure retraction is enabled in Cura. Change retraction distance from 4.5mm to 5.5mm. Retraction distance is not in Cura - it's on the printer itself. Or maybe more. Why should Daid weigh in? He already did in a posting up above - maybe you missed it. #7. That stringing you got shouldn't be too hard to remove. But if you want even better quality print 2 robots side by side at the same time. This helps a lot. That's how I did this one:

I think this sounds great at first but sometimes other things need to be considered. If the switch is broken and shorted it will always report closed so step 1 may be an infinite loop plus you might break the glass. 7mm is a good compromise.

You should be able to get 50 micron XYZ no problem with resin technology (form1, b9creator, titan). But not with FDM (heated plastic). Plus my understanding is you can use these resins for lost casting technology which is what you want. You really really should look into form1 or b9creator. These are amazing machines although the resin expensive. http://b9creator.com/ I just looked at the above page and there are several sliding "pictures" at the top and one of them talks about investment casting and even mentions metal casting and jewelry.

lol. So the last guy I said it probably wan't the belts but it was. Well now on these above images of gray parts I think it *is* the belts. Usually the short belts meaning if this is a UM1 just slide the motors down a little tighter. Also you have a little bit of underextrusion - what print speed, layer height and temp are you using? You might need to either raise the temp or lower the print speed or print thinner layers. 240C is a relatively safe upper limit for PLA so if you are printing cooler than 240C try raising the temp 10 or 15C. If you are already at 240C try cutting back the speed by 30-50% just for kicks so you can see some quality improvements - or maybe you don't care.

@suminvent - please post pictures. What you see as underextrusion could be something else. It could be a fan/temp issue. It could be a bad nozzle (deformed nozzle due to damage). It could be the bent tube. It could be a lot of things. I doubt it's leveling unless it only happens on the bottom layer. Oil will not make any noticable difference to your print other than allow the material through the tube better. Plastics are made from oil by the way. To post pictures: http://umforum.ultimaker.com/index.php?/topic/4525-how-to-upload-an-image-to-the-forum/

Yes. That's a common problem. It seems to vary depending on the exchange rates and maybe sometimes customs misses certain items but it seems like about 1/3 of the people in USA have to do this. Should be in the $100 to $200 cost range. They won't release it until you pay.

I printed a knob for something outdoors. It has not changed color in a year now. If you google "pla outdoor" I think you will find other people who have done better experiments and you will find that PLA does very well outdoors. Better than ABS I think.

UM Original or UM2? The UM2 shouldn't grind most filaments as it has a lower current applied to the feeder so that it will slip backwards instead of grind. And did you have mega retraction? If um2, count the M11 commands in the gcode and look at the final extrusion position in mm and see how many retractions you had per mm. I've done 8 and was fine (same filament went back and forth through feeder 8 times. On average meaning sometimes more than that). On UM1 in general you can raise temp or lower speed to get less forces, less pressure in the head, which reduces grinding.

That sounds great but should I do that now or wait until steve finishes with combining?

People are going to say "tighten your belts" and that could be it but I don't think so as your infill is touching the borders very nicely. When that hole is printed, the printer is squirting out a thin line of plastic that has a tendency to cool fast and shrink just a little and start to act like a rubber band for a second before it freezes. In that moment - after it leaves the nozzle, but before it turns solid it is pulling and thinning and it tends to pull off the layer below a bit towards the center of the circle a tiny bit. Also it is pulling on the layer below trying to get *that* layer to also shrink a bit. The reason the shape is different has to do with the cura slicing changes which has the circle start in a different location. There's nothing wrong with Cura - it's just that it starts the circle at a different spot. The fix is generally more fan, longer layer time, lower temperatures, slower printing. In that order of importance. So: 1) make sure fan is 100%. Make sure it is blowing and not sucking. consider adding a second fan (a table fan?). 2) make sure layer time is at least 7 seconds if you want this to come out nice. This makes it so that the layer below has more time to cool before the layer above is applied. 3) If you have a UM2, keep the temp no higher than 60C for PLA. I would try 50C even (lower than 40C and you start to get danger of parts not sticking as well). Also lowering nozzle temp to 200 or 190C might help. 4) Printing at 20-30mm/sec might help also as it's possible this is an overextrusion issue on speed changes and printing slower can help that.