gr5

If you are in Boston area, come on by and we can fix it together - this is trivial to fix for an experienced technician.

It's unlikely the sensor. When things heat up the expand (think "move"). This movement can cause wires to no longer be in contact. The most likely cause of failure is the terminal block on the actual heated bed - I would take it all apart and reflow the solder on all 4 of those connectors. The next most likely problem is the wiring - you can simply loosen the 2 screws that hold the temp sensor wires (skinnier wires) and then re-insert and retighten the wires. Third most likely problem is the terminal block underneath the printer. Least likely problem is the temp sensor itself. You could heat it up and then when temp jumps cut power and quickly remove temp sensor wires form under printer and then measure them and measure the resistance right on the temp sensor itself. Repeat for different parts of the path. Also push and flex the bed a bit while you measure to see if it's intermittent trace (sometimes the trace has a hairline crack).

What labern said. I assume this is the width of a pencil. Print 2 at once and make sure you have "all at once" mode and not "one at a time mode" chosen in the menu.

It's a lot of work to create your own. The one from Ultimaker is amazing because it completely rebuilds the platform which was the weakest part - before the upgrade I was releveling between every print. Now I can level once and a month later it's still fine even after removing the glass and putting it back in. Even after wacking pretty hard to get prints off the bed when they stick extra well. It's a huge improvement that you wont get with just the heat part.

What are "uprights"? The pattern in your filament looks okay to me. Anyway everywhere in your print I see underextrusion - the flat areas have holes in them indicating underextrusion and the most recent layer walls look very underextruded. CAUSES FOR UNDEREXTRUSION AND HOW TO TEST FOR THEM AND REMEDY THEM As far as underextrusion causes - there's just so damn many. none of the issues seem to cause more than 20% of problems so you need to know the top 5 issues to cover 75% of the possibilities and 1/4 people still won't have the right issue. Some of the top issues: 1) Print slower and hotter! Here are top recommended speeds for .2mm layers (twice as fast for .1mm layers): 20mm/sec at 200C 30mm/sec at 210C 40mm/sec at 225C 50mm/sec at 240C The printer can do double these speeds but with huge difficulty and usually with a loss in part quality due to underextrusion. Different colors print best at quite different temperatures and due to imperfect temp sensors, some printers print 10C cool so use these values as an initial starting guideline and if you are still underextruding try raising the temp. But don't go over 240C with PLA. 2) Isolator - this is most common if you've printed extra hot (>240C) for a few hours or regular temps (220C) for 100 hours. It warps. It's the white part touching the heater block. Test it by removing it and passing filament though it by hand. 3) Curved filament at end of spool - if you are past half way on spool, try a fresh spool as a test. 4) curved angle feeding into feeder - put the filament on the floor -makes a MASSIVE difference. 5) Head too tight? Bizarrely MANY people loosen the 4 screws on the head by just a bit maybe 1/2 mm and suddenly they can print just fine! Has to do with pressure on the white teflon isolator. 5b) Bowden pushing too hard - for the same reason you don't want the bowden pushing too hard on the isolator. 5c) Spring pushing too hard. Although you want a gap you want as small as possible a gap between teflon isolator and steel isolator nut such that the spring is compressed as little as possible. 6) clogged nozzle - the number one problem of course - even if it seems clear. There can be build up on the inside of the nozzle that only burning with a flame can turn to ash and remove. Sometimes a grain of sand gets in there but that's more obvious (it just won't print). Atomic method (cold pull) helps but occasionally you need to remove the entire heater block/nozzle assembly and use flame. 7) Temp Sensor bad - even the good ones vary by +/- 5C and bad ones can be any amount off - they usually read high and a working sensor can fail high slowly over time. Meaning the sensor thinks you are at 220C but actually you are at 170C. At 170C the plastic is so viscous it can barely get out of the nozzle. You can verify your temp sensor using this simple video at youtube - on you tube search for this: mrZbX-SfftU 8) feeder spring issues - too tight, too loose 9) Other feeder issues, one of the nuts holding machine together often interferes with the feeder motor tilting it enough so that it still works but not very well. Other things that tilt the feeder motor, sleeve misaligned so it doesn't get a good grip. Gunk clogging the mechanism in there. 10) Filament diameter too big - 3mm is too much. 3mm filament is usually 2.85mm nominal or sometimes 2.9mm +/- .05. But some manufacturers (especially in china) make true 3.0mm filament with a tolerance of .1mm which is useless in an Ultimaker. It will print for a few meters and then clog so tight in the bowden you will have to remove the bowden from both ends to get the filament out. Throw that filament in the trash! It will save you weeks of pain 10b) Something wedged in with the filament. I was setting up 5 printers at once and ran filament change on all of them. One was slowly moving the filament through the tube and was almost to the head when I pushed the button and it sped up and ground the filament badly. I didn't think it was a problem and went ahead and printed something but there was a ground up spot followed by a flap of filament that got jammed in the bowden tube. 11) Hot weather. If air is above 30C or even possibly 25C, the air temperature combined with the extruder temperature can soften the filament inside the feeder such that it is getting squeezed flat as it passes through the feeder - this is obvious as you can see the problem in the bowden. The fix is to add a desk fan blowing on the back of the printer. 12) Crimped bowden. At least one person had an issue where the bowden was crimped a bit too much at the feeder and although the printer worked fine when new it eventually got worse and had underextrusion on random layers. it's easy to pull the bowden out of the feeder end and examine it.

A bearing is when any two things slide across each other in one or two directions but keeps the thing from moving in one or two other directions. On the bed there are 2 vertical 8mm rods that pass through 2 8mm cylinders. Those 2 cylinders are the bearings and inside they have ball bearings. Those are a specific type of cylindrical bearing called a "linear" bearing that does not rotate around the rod well (twisting has friction) - but slides along the shaft with very little friction. Whereas the cylindrical bearings inside the print head have no ball bearings and instead are simple cylinders that allow sliding *and* twisting motion.

I meant in the terminal block on the heated bed plate - unscrew the 2 screws, remove the 2 wires, reinsert, retitghten. Repeat also on PCB under the machine. Points of failure are most likely solder or screw connectors.

your bed is probably always about 7 degrees cooler than you think then so that when you ask for 60C you probably get 53C. I would disconnect the wiring underneath the UM2 and measure it there then measure it at the actual part - the tiny PT100 and at every junction in between to see if the PT100 is now damaged and reads 109 or if one of the many connections has 1 ohm resistance somewhere along the path. Or alternatively change the default PLA bed temp to 67C.

You could message tinkerGnome directly - he has made many modifications to the UM2 firmware we call "tinker marlin" and he may have fixed the M23 bug it's a looong thread to read: https://ultimaker.com/en/community/view/7436-more-information-during-print

You can rotate the steel coupler without removing anything else - I recommend removing just the front left very-long thumb screw so you have better access to the steel nut coupler. Then heat the nozzle to 150C and then use a hex wrench or other thin metal stick to rotate the steel coupler such that the nozzle goes down (counter clockwise from above). But not so much that it touches the fan shroud - use a bright light and peer through the cracks or let it hang loose and repeatedly put it on and off and feel where the metal shroud touches the block.

Maybe I am wrong and it's not touching. With the i2k chip in there the spring is tighter and so now there is a LOT more pressure on the white teflon part. You want the pressure on the white teflon part as small as possible without touching the fan shroud. Since you *don't* have the olsson block you have the smaller original block and so you have more space to deal with and the nozzle can be much lower:

X could be on anything - I had a .15mm nozzle with an X only. Those are long gone.

A photo or video would be helpful. There are 3 possible issues you are describing each totally different. First realize that leveling only affects the first layer. by the time you get to the 3rd layer all leveling has been self repaired by the fact that each layer sits on the previous and eventually they get to the right position. This is easier to show in pictures than words. Is your problem top and bottom layers only? If so try turning off the "combing" feature - that will make a huge difference. And make sure retractions are enabled. Please post picture.

If your walls are not the issue then look at your model with "xray view" in cura. This will show in red any areas that violate the "manifold model" rule (it shows you any place you have internal planes or holes). Also you can try the "fix horrible" settings - usually A or B fixes many sketchup issues but it can also fill in stuff that isn't supposed to be filled in - like a chimney or closet. Also sketchup has plugins to test that your model is manifold. Also you could use the netfabb web service which will repair your model. It's free.

There are 2 very common problems here: walls too thin, sketchup. You are probably experiencing one of the two. Definitely adding a plane is not good - Cura hates it when the model is not solid. Adding internal planes or holes in walls is not allowed. It means you are modeling something in sketchup that can't exist in real life. All CAD programs meant to design things in real life no longer allow stuff like infinitely thin planes (like sketchup allows). It's just built into the way the CAD software works - there's just no mechanism to create an infinitely thin plane or to drill a "hole" in a cube without the hole itself having walls. Anyway having said that it might be simly that the walls are too thin - a quick check is to set your nozzle size much smaller - try 0.1mm just to see what happens. And ALWAYS set shell thickness to a multiple of nozzle width even for these quick experiments or the experiment will be invald. For example if you set nozzle wicdth to 0.39 and sheel width to .8 it will change nothing. it will do the same thing as if nozzle size is 0.4.

I think the um2 drifted apart long ago - I think the last merge from the main marlin branch was 6/27/2013 07:41:11 (I could be interpreting git wrong). I think the problem is probably that the menu system changed so much from the main marlin branch that Daid was no longer able to safely merge in the latest features. You could probably create a fresh github copy of um2marlin, make the M23 fixes, test the fix, and then send a pull request to Daid. All us um2 users would probably appreciate that.

Or you can contact support and get some new bearings. They probably only cost a few dollars but that's probably irrelevant because if it's less than a year old they should just send you new ones.

there were some 3dsolex 1mm nozzles with 4 dots (1 + 2 + 1). Also there were a lot of 3dsolex .8mm nozzles with the smaller cone - similar to the .25mm smaller cone. With zero dots. In fact the 4th one down in your table should probably have the smaller cone.

My guess is that the nozzle block is now touching the fan shroud somewhere and the nozzle is cooler than desired so it's like you are printing 20C cooler. Also did you re-level? Each time you change the nozzle it is at a slightly new height. Can you post a picture of your print head taken from the front that shows the spring and teflon part? Do you have the Olsson block also?

Your Z motor is moving double speed. something is wrong with the PCB that controls it. I would try a factory reset because that will reset the "steps/mm" setting. It's also possible that the stepper chip (the servo controller chip) it is set to 8 microsteps instead of 16. That would also make it move double speed. If none of these things slow down the Z then you should contact support.ultimaker.com and point them to that video you showed and tell them gr5 thinks the Z is moving at 2X speed and distance for some reason. Oh - you could move the Z say 10mm and see if it actually moves 20mm. You can do this many ways - tinkergnome's marlin lets you do that I think but the easiest way would be with pronterface/printrun which is a free, easy to use - it has a nice gui - you hook your computer to the um2 with the standard usb cable and tell it to move 10mm in Z: http://koti.kapsi.fi/~kliment/printrun/

This is a common problem. It could be your model (check it in Cura layer view very very carefully around 12mm height) or more likely it is Z issues. There are known Z issues with the Z driver in the PCB where recent boards put out too much current and it gets too hot and fails intermittently and the bed falls about 1mm and recovers. These tend to be almost always the same height but a little different each time. Then the most likely cause - something with the two Z bearings. Apparently you shouldn't put oil on them as it gets in the ball bearings and can gum them up. Maybe remove the Z rods, remove the Z bearings and clean the bearings very well - I would probably try WD40 and then dry them completely of all oils and cleaners and then assemble it all back together. Maybe one drop oil on each Z rod but no more. Probably residual oil from WD40 is enough.

You can't measure the resitance with the power on. You can't trust that measurement so ignore it. The way a multimeter and the way the UM measure resistance is by putting some current through the temp sensor and measuring the voltage across it. If both instruments are putting current through the temp sensor it will get a higher voltage and both will read higher than intended. The multimeter puts much less current though (much more sophisticated instrument) and so the UM doesn't notice but the multimeter notices when the UM has power on. The error you are getting only occurs if you have SEVERE errors in resistance such as 0 ohms or 1000 ohms. This can only happen if you have a short circuit or open. Short circuit is very unlikely. What's much more likely is a wire is just barely connected and moving the bed or touching the cable moves it to an open. The problem could be where the cable connects to the PCB but much more likely it is at one of two places: either the screw-down connector on the board or in the solder connection between the connector and board. I recommend you reheat all 4 solder connections and remove and re-insert the PT100 wiring. The PT100 can indeed fail but the odds are 95% wiring problem, 4% PCB proglem, 1% PT100 problem (one person on the forum convinced me it was really their pt100 that was at fault - about 2 years ago). https://ultimaker.com/en/community/view/5791-error-stopped-temp-sensor-bed-solved

For people who bought nozzles in the past and have a mixture of types I know it's confusing. It's confusing for me also. Lately it's simple but because of changes in the past.. anyway here is a guide for Labern. And it's easy to tell .25 from .8 because .8 is 3X larger hole.

This is cool. And smart. 1) What bed temp did you use for ABS portion? What temp for PLA raft? I recommend 60C to 70C for the PLA raft but if you print *only* ABS you want the bed at 100C minimum (105 or 110C even better but it's hard to reach those temps without covering up your printer and getting the air up to 40C). The temp of 100C is mostly so the ABS sticks well so you could probably do the whole thing at 60C. Is it possible you never tried to print ABS at 100C? It's also important that the bottom layer is pushed well into the glass so it sticks well with the glass (covered with very thin layer of hair spray). Sometimes all you have to do is turn the 3 screws counter clockwise a half turn and suddenly everything sticks better. Using "brim" feature (or raft I suppose) helps quite a bit also with sticking to bed. 2) Switching between PLA and ABS is often problematic. In the short term going from ABS to PLA often causes clogs of bits of ABS and ruins your print. In the long term printing at ABS temps often wears out the teflon part faster but ABS doesn't care as much - then switching to PLA often you suddenly get major underextrusion. This is probably irrelevant to this technique though. 3) The black PLA lines aren't straight - they are curvy - why is that? Was it like that when it was first laid down? Or only did it happen when ABS was added? Or did it happen only when removing from glass?

Swordriff is amazing at constant improvement. He is indeed the one who figured out how to get those tiny markings on the nozzles. But as a backup they have other markings (dots). He is definitely more clever than the people at e3d-online who created this format of nozzles - they never thought to add 2 dots to the same hex flat face when they come up with a new nozzle size. Swordriff thought of it.