gr5

When you had it all apart you should have tried pushing some filament through the white teflon isolator to see how much friction. I've seen isolators that have over 1kg of force needed to push filament through and that can get worse when under pressure.

I guess that could be due to underextrusion. Maybe your temperature is much cooler than you think. Many sensors are off by 10C. Try this temperature test:

As the purple text above says, make sure your block is not touching the fan shroud. The round nut (yellow in upper picture, dark gray in lower picture) is designed to be able to adjust and make the 2 nozzles the exact same height with dual-printing but dual-printing never worked well enough.

It could be a floating point rounding issue where the object is slightly thinner than .8mm wall thickness just before it gets thicker. Or maybe that's intentional in the design. As a quick experiment set shell width to .39 .38 .37 .36mm and so on and see if/where the missing portions are once again printed.

Well, layer height isn't related to the line width or the nozzle width and neither is feed rate. "line width" is something that the old cura calculated based on shell width and nozzle size. If shell width was an integral multiple of nozzle size then line width was always equal to nozzle size. This was very confusing in the old cura because you could say nozzle size was .4 but if you asked for a shell of .5mm then ALL line widths were printed .5mm wide as though you had a .5mm nozzle and people would get massive underextrusion and they didn't realize it was because they had the wrong shell width. If you asked for a shell of .9 in the old cura with a .4 nozzle you got two passes of .45mm line width each. And all the infill was also .45mm line width even though infill shouldn't be affected by shell width.

Theory1: What type and version of firmware do you have on your Mendel. It looks like it is starting and stopping along the straight edge and it over extrudes those bumps in a vertical pattern each time it stops. Is that possible? Do you know if you have Marlin? Sprinter? Sailfish? Teacup? And which version. I've seen older firmwares do exactly the pattern I'm seeing on your Mendel. Theory2: Could those bumps be infill lines showing through? If you stop the print half way or if you look at the print while it is printing - do those bumps line up with the infill touching the outer edge? You want the "shell" of your part to be 2 passes. So if your nozzle is .4mm you want a shell of .8mm. If your nozzle is .5mm you want your shell at 1.0mm. Check that - very easy to fix if that is the issue.

I don't think you have to worry about that. You are confusing ultimaker with makerbot. The head is designed to be taken apart. You might break something like the temperature sensor but the lesson will be worth the cost of a new one. Every owner of an ultimaker has likely been forced to take apart the head within a month of purchase. You live in the Netherlands so just give UM a call. They will probably want to know your serial number. I think they provide support even if you bought it from a reseller. The people in support are knowledgeable and great and speak both Dutch and English very well. Calling UM usually works the best for support as they usually answer the phone right away - if you get a recording try again an hour later.

Check out the vertical lines on these photographs: https://ultimaker.com/en/community/view/2872-some-calibration-photographs Also consider rotating your part by 15 degrees and printing again to see if that makes a difference.

We really need to see a photo. Could the ribs be part of the STL file? There's lots of causes of vertical ribbing such as ringing and temperature issues, STL file stuff, interactions between floating point math and STL files and Cura, hardware issues. These different types of vertical lines look different Do you have a cell phone? Cell phones are usually fantastic at macro photography.

You guys are all nuts. This forum is as active as ever as far as I can tell. There's so many posts I miss a ton of them and never get to read them all. Even if I spend an hour a day I can't get through them all. You just have to change your workflow a bit. Some of the nice features of the new forum - you can bookmark lots of useful pages like this one: https://ultimaker.com/en/community?sorting=latest&filter%5Btype%5D=question-unanswered&filter%5Btype%5D=all That above link shows you recent topics. If you see a topic you are interested in then click the "follow +" icon and everytime you come to the forum go to the "bell" at the top of the screen and it shows you all the responses to your posts and posts in the threads you are interested in. Also in that above link - if you have a distinctive icon for yourself it's easy to see if you've recently already posted in some of those or you can just look at posts that no one has responded to yet. I don't know what you mean about losing your session. I can go many days without having to log in. Regarding the email feature - that is what I miss the most. The plan is to add that back in. Plus email all the old users. All the old posts are still in the new forum. You can get to them through google most easily - just search for the topic and your username and/or text within the topic and most old things aren't hard to find.

Don't understand the question. What you call "nozzle diameter", Cura now calls "line width". Line width controls the distance between traces when you have a 100% infill (like bottom and top surfaces) and it controls how much plastic to extrude (the amount to get the right line width). Those values used be controlled in the old cura by a combination of shell and nozzle. Now it's better - you have direct control - at least for top/bottom surfaces. I'm not sure what the new cura does if shell width isn't a multiple of line width.

True! It's actually glass. Glass filled. It is supposed to keep it stronger when it is at higher temperatures but I'm not convinced it helps. You can tell the glass filled ones as they are slightly grayer than white. lol! That's not good. but I'm sure nothing broke.

There will definitely be lots of printers added to Cura in the future. As in the past though, mostly only when someone from the community creates a profile and then does a pull request. I recommend sticking with the slightly older version of Cura for a few more months and then checking back. Even Ultimaker owners are mostly using the older Cura I suspect. But it gets better every week!

Well look at those "lines" inside your part and how deep they are (not very - maybe 1/4 mm?) and if the play in the nozzle is the same amount then that's probably it. I've never felt what you describe - there was someone else who had a similar problem - nozzle was loose. He was able to fix by just rebuilding the head and tightening up a few things. The bearings in the head are linear only so they use ball bearings and maybe you lost some. You could order new ones. The bearings in the blocks however are simpler - just a tube - no ball bearings. Because they have to allow rotational *and* linear motion.

I disagree. If you have play in your system and you draw a circle and approach from the inside you will get identical circles every time (slightly elliptical if play is only on one axis - either way the circles will be smaller than commanded). And each "circle" will be on top of the one below it perfectly regardless if you go clockwise or counter clockwise and where you approach the circle as long as you approach radially. However if you aproach the circle from the outside then you won't get round circles - you will get these "shelves" and if you approach from different directions or rotate clockwise versus counter clockwise in combination you get different "shelves" on the inner circles. It's exactly as expected. In fact if you approach from outside radially and then make a complete circle you won't end up where you started the circle.

aliexpress.com. There stuff tends not to be great but hopefully they can't screw this up. They can screw up a nozzle but hopefully not a coupler: http://www.aliexpress.com/item/3D-printer-accessory-Ultimaker-Hot-End-Isolator-Coupler-PTFE-Teflon-inner-sleeve-for-3mm-filament-great/32226862149.html Try ebay also.

ALWAYS look at your part in layer view before printing it. It will show the supports there. I would flip it over - the quality of the surface will be much worse on the downward facing portion of your print so that's where you want the parts people are less likely to see.

I recommend printedsolid.com for filaments in usa. I've met the owner - great guy. He's on this forum somewhere or used to be. Don't try 1.75mm filament - too much of a hassle. It's fine to just switch filaments and turn the big gear until the old color is gone. or you can do a cold pull like I do - when a print finishes, turn the big gear so filament isn't retracted (or reheat head to 180C and then extrude a tiny bit of filament). Then set temperature to 100C and let it cool. Then release the tension on the feeder and pull hard downwards on the filament to remove. If you need more than about 10 pounds of force raise the temp by 5C a few times - it should come out around 95C to 110c - somewhere in there. If you do it perfect the end of the filament is shaped like the nozzle tip inside including the .4mm channel at the end. Now you can switch filaments and there will none of the old color plus you get any dirt/gunk out of the nozzle which is great maintenance.

Oh - and as for high friction - push the head around - it should be easy to do with the smallest finger on each hand placed on the side blocks. Usually excess friction comes from endcaps too tight. The second most common cause is long belts too tight.

That was my first though: "I bet the difference between these layers is that some are clockwise and some are counter clockwise". I think it's play. You can get play/backlash from too loose cables but also from too tight cables which can cause friction. Really any high friction can cause play. Play means when you command the head to move and then stop, the head stops a bit short - again either friction is so high that there is still a lot of tension on the belt even when it stops, or the belt is loose enough that the head doesn't move far enough. Other things being loose can cause play - a loose nozzle within the print head for example. Try pushing the nozzle around a bit when it's cold and power is off and see if it moves before the head starts moving. Pluck the 6 belts (6, NOT 4 if you only found 4 belts keep looking). Listen to the pitch. It should be a very low pitch but it should have an audible pitch - so > 40 hertz. Usually it's the short belts meaning you might have to length the slots for the motors. Also consider locating some clothespins - you can remove the spring off the clothespin and that makes a great tensioner - that's what the UM2 uses hidden inside the blocks.

Oh - one thing that hasn't been mentioned. Look at all the advanced settings and make sure all the printing speeds are the same. If the inner shell is for example 50mm/sec and then the outer shell is at 40mm/sec it will look like crap because it will overextrude the outer shell. So make all the printing speeds 0mm/sec which uses the nominal speed and of course the move speed should be 150-300mm/sec (that's a non printing speed).

Other's have already said this but you didn't say if you checked these things. FANS! Fans. Did anyone say fans? make sure both fans are at 100% by the time you get to these. Tower. Put a 10mm by 10mm tower next to this that is .1mm taller than your part. This allows the two prongs to cool while it prints these. Place the tower such that the FANS will blow on the two prongs while printing the tower. print at 20-35mm/sec. No slower than 20mm/sec. No faster than 35mm/sec. Fans. Lower temp of filament. At .1mm layers 20mm/sec (yes, that's slow) you can probably print around 180C. Crank the fans. If you can add a window fan or desk fan that will definitely help. Try another color filament. In general most white PLA filaments are more difficult and quality isn't as good. Fans.

Video please - just film with phone and upload to youtube.