gr5

Can you show what's on the Z axis? is it a print bed or is it the print head? I think the 0.2mm is normal for Z height error. That probably just means you are squishing the bottom layer a lot. That's good so that your parts don't come loose during printing. 100g of weight? I was thinking more like 1 or 2kg. Do you have exercise weights? Hand weights? Bricks?

A bend in the z rod or wobbling will create a smoother, harder to see, wave like pattern. Your issue is different. What happens in your case is that the bed isn't always moving a consistent amount - it gets stuck a bit and so it over extrudes a layer (not enough space for the plastic extruded) and then on a later layer (sometimes the next) the bed moves the full amount of all previous desired moves that were incomplete and you get an underextruded layer. One thing to try is to add a brick or some heavy object so that when the Z screw rotates the bed is more likely to come all the way down and rest on the threads once again (or if it's your print head that goes up then a weight can help wilt that also). Usually the fix is to clean the Z rod. If you want to do an extra good job, then remove it completely (typically the stepper is attached which is fine) and then clean it with wd-40 and tooth brush and dry completely with rag or paper towels. I'm not sure about lubrication. Ultimaker recommends a particular grease (don't know the brand or anything) and they recommend oil for the straight rods (no oil on threaded rods). I don't understand the logic of these choices at all. If you have a fancier, more expensive Z nut (like $3 instead of $0.50) then it should have ball bearings inside and you probably don't want any grease or any oil (as this collects dust in with the ball bearings).

I was going to say "change the teflon coupler". How long ago did you change the coupler - it's good to keep one printer just for ABS and one just for PLA as the higher temperatures needed for ABS make the teflon part fail much faster. Anyway here is a complete list of underextrusion (which includes not printing at all) issues for the Um2 #18 and #22 and #23 in particular would behave as you describe where ABS would be fine and PLA would clog after 5 to 30 minutes. Although because the printer speeds up each layer for the first 5 or so layers and because the fan speeds up also, almost any issue below could manifest only after a layer or 3 are complete. CAUSES FOR UNDEREXTRUSION UM2 AND HOW TO TEST FOR THEM AND REMEDY THEM One can quickly check the feeder (it takes seconds) so I would always do that first. The feeder on UM2+ and UM2 can push with 10 pounds (5kg) force easily so first thing is to lift that lever (if um2+, if um2 regular do move material) and insert filament so it is only part way into the bowden (e.g. half way). Then move the filament with "move material" command in menu so the feeder is energized and then pull down on the filament under the feeder. You should be able to pull with 5 to 10 pounds force without it slipping. Then have it move the material up while you pull down. 5 pounds force (2kg) is enough to make decent prints at moderate speeds listed below but you need 10 pounds (5kg) to print fast (e.g. 0.2mm layers and 60mm/sec) 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) and .4mm nozzle: 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) Shell width confusion. Shell width must be a multiple of nozzle size (in cura 15.X. In cura 2.X it doesn't matter as much but still makes a difference). For example if nozzle size is .4mm and shell width is 1mm cura will make the printer do 2 passes with .5mm line width which is possible but requires you to slow down much more to make a .5mm line out of a .4mm nozzle. If you really want this then set nozzle size to .5mm so it's clear what you are asking Cura to do for you. 3) Isolator - this is most common if you've printed extra hot (>240C) for a few hours or regular temps (220C) for 500 hours. It gets soft and compresses the filament under pressure. It's the white part touching the heater block. It's very hard to test when not under full pressure (spring and bowden) so sometimes it's best to just replace it. Also if you notice parts of it are very soft (the blacker end where it touches higher heat) then it's too old and needs replacing. 4) Curved filament at end of spool - if you are past half way on spool, try a fresh spool as a test. 5) curved angle feeding into feeder - put the filament on the floor -makes a MASSIVE difference. 6) UM2 only: 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. 6b) UM2 only: Bowden pushing too hard - for the same reason you don't want the bowden pushing too hard on the isolator. 6c) Um2 only: 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. 7) 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. I found soaking with acetone does not help with caramelized pla. Even overnight. Maybe it works on ABS though. Simpler cold pull: https://www.youtube.com/watch?v=u07m3HTNyEg 😎 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 (rarely) 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 9) feeder spring issues - too tight, too loose. On the black UM2 feeder you want the tension such that you can clearly see the diamond pattern biting into the filament. You want to see at least 2 columns of diamonds. 4 columns is too much. On the white UM2 plus and UM3 feeders you usually want the tension set in the center. 10) Other feeder issues, one of the nuts holding UM2 and UM3 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. 11) 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 11b) 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. Having the "plus" upgrade or using the IRobertI feeder helps you feel this with your hand by sliding the filament through the bowden a bit to see if it is stuck. 12) 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. Not an issue on the UM3 or UM2 "plus" series. 13) Crimped bowden. At least one person had an issue where the bowden was crimped a bit too much at the feeder end 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. 14) Worn Bowden. After a lot of printing (or a little printing with abrasive filaments) the bowden resistance can be significant. It's easy to test by removing it completely from the machine and inserting some filament through it while one person holds it in the U shape. Preferably i nsert filament that has the pattern from the feeder. 15) Small nozzle. Rumor has it some of the .4mm nozzles are closer to .35mm. Not sure if this is actually true. I'm a bit skeptical but try a .6mm nozzle maybe. 16) CF filament. The knurled sleeve in the extruder can get ground down smooth - particularly from carbon fill. 4 spools of CF will destroy not just nozzles but the knurled sleeve also. Look at it visually where the filament touches the "pyramids". Make sure the pyramids are sharp. 17) Hot feeder driver. I've seen a more recent problem in the forums (>=2015) where people's stepper drivers get too hot - this is mostly a problem with the Z axis but also with the feeder. The high temps means the driver appears to shut down for a well under a second - maybe there is a temp sensor built into the driver chip? The solution from Ultimaker is that they lowered all the currents to their stepper drivers in the newer firmware. Another solution is to remove the cover and use desk fan to get a tiny bit of air movement under there. TinkerMarlin lets you set the currents from the menu system or you can send a gcode to lower the current. Ultimaker lowered the default currents in July of 2015 from 1300ma to 1200ma for X,Y,Z but left extruder at 1250. Other people (I think the support team of a major reseller but I forget) recommend X,Y,Z go down to 1000mA. M907 E1250 Above sets the extruder max current to the default - 1250mA. So try 900mA. This will only change until next power cycle so if you like your new value and want to save it use M500. You can just put these into an otherwise empty gcode file and "print" this and it will change. Or get tinkergnome marlin! You will wonder how you lived without it: https://github.com/TinkerGnome/Ultimaker2Marlin/releases M907 E900 M500 18) third fan broken. This tends to cause complete non-extrusion part way through a print. In the rear of the head for UM2 and the front of the head for UM3. Without this fan several things can go wrong. It can take a while as usually you also need several retractions to carry the heat upwards. There are a few failure mechanisms and I don't understand them all. One of them is probably that the molten PLA spreads out above the teflon and sticks to the metal in a core or fills the gap at the base of the bowden in UM2. Later it cools enough to keep the filament from moving up or down. 19) Spiralize/vase mode. This is a rarely used feature of Cura but you might have left it on by accident? In this mode the wall of your part is printed in a single pass. So if you have a .4mm nozzle and the wall is .8mm thick it will try to over extrude by 2X. This is difficult to do and may instead lead to underextrusion. 20) non-standard or bent fan shroud. Sometimes people print some fan shroud off of thingiverse or youmagine out of PLA or ABS. Some of these are great but most of them are crap. One needs to do good air flow modeling. Also if it's PLA it will slump and direct air differently. Air directed at the block or nozzle can cause severe underextrusion and also sometimes HEATER ERROR. Put the original shroud back on or just turn off the fan to prove that the fan is the problem. 21) Firmware settings - for example UM2+ firmware on UM2 or vice versa will cause 2X over extrusion or 2X underextrusion. Downgrading or changing firmware can mess up steps/mm and other settings - so if you updated firmware and then problems started then do a "reset to factory settigns" which corrects all the steps/mm values. 22) too many retractions (this causes complete failure) - if you have too many retractions on the same piece of filament you can grind it to dust. 10 is usually safe. 20 is in the danger zone. 50 should guarantee failure. You can tell cura to limit retractions to 10 per a given spot of filament. Do this by setting "maximum retration count" to 10 and "minimum extrusion distance" to your retraction distance (4.5mm for UM2 and 6.5 for UM3 and 8mm for S5). 23) Brittle filament. Espciallty with older PLA but even brand new pla can do this. If you unspool some (for example if it's in the bowden) for many hours (e.g. 10 hours) it can get extremely brittle and it can snap off into multiple pieces in the bowden. It's not obvious if you don't look for this. Then it starts printing just fine and at some point one of those pieces reaches the print head and gets hung up somewhere and the printer suddenly stops extruding for now apparent reason. This usually happens within the first meter of filament - once you get to printing the filament that was recently on the spool it should be fine from then on. 24) The "plus" feeder can have an issue where the filament doesn't sit properly for one print and it permanently damages the arm inside the feeder as shown by this photo - the hole is ground down asymetrically: http://gr5.org/plus_feeder_issue.jpg 25) Other feeder issues. You can test the feeder by putting the filament only part way down the bowden and with the feeder electrically turned on (or moving) pull very hard on the filament until it slips. You should be able to pull with about 5kg or 10 pounds of force before it slips. 4kg is acceptable. 2kg is a problem. If the stepper motor isn't engaged you can try going into the move menu. After a minute or so power is removed again from the feeder stepper.

First of all print towards the edge of the printer that has the best support. Secondly, print much slower as Smithy suggests. Finally - look into ways to stabilize your print bed better. Use google to see what other people have done.

Don't use raft. It's an old technology that isn't needed anymore and results in ugliness on the bottom of prints - just like your photo. Here is much more info about how to get parts to stick to your printbed without using a raft. why rafts were created (long ago, before PLA filament existed and before heated beds). Why parts peel up at the corners. How to keep that from happening.

255C is a good temperature for Nylon. I don't think there is ever any need to go higher than 260C. But you can get a version of Marlin that goes higher. I'm sure the um2+ heater can get above 260C no problem but if not then you could get a higher wattage heater. I guess the main issue is that the nylon insert can go bad faster. they are cheap - around $20. You can replace them every 400 hours of printing or so and learn how long they last and if you really want to you can buy an i2k from my store which will keep the nylon much cooler such that it lasts for several thousand hours. Or you could buy a 3rd party all metal hot end (but you can't print PLA with all metal hot ends and PLA is such a wonderful material).

Note that nylon has a few tricks so come back here with questions when you start printing.

You will need to cover the front and I recommend also the top. There are covers for the printer that you can buy from for example printedsolid.com or you can just do what I do: put a clear plastic gallon ziploc on the front and a cardboard box on the top (the box that normally holds many reams of paper that are sitting around near photocopiers). That box - the photocopy paper box - is the perfect size for the top of a UM2. Zero modification. You barely need any tape. It just sits there perfectly. Yes you need a ruby if you print CF or glass fill. And you probably need to upgrade the feeder at some point. The sharp points inside the gnurled wheel in the feeder can get worn down and if they do then get a bondtech feeder. If you get a UM2+ then you can get the cheaper (and better) option: the DDG. About $95. I recommend 0.6mm ruby/sapphire as they are less likely to clog with filled filaments. The 3dsolex rubies are nice in that they have dual passages inside to more thoroughly heat up the filament. I sell 3dsolex rubies and DDG for UM2+ at thegr5store.com. It doesn't matter much that CO is dry - well it helps - but you will still probably want to keep your spools of nylon in a 2 gallon zip lock (one bag for every one or two spools) along with dessicant when not in use. I like this dessicant as you can recharge it in the microwave: https://www.amazon.com/dp/B01JOPJ0HA/ref=cm_sw_em_r_mt_dp_U_pGpDDb61T4H25

You need to pull that smaller gear outward along the stepper shaft. I had a um plus where that gear failed in some way (I think it was the same way? Sliding along the shaft ever few minutes?) and I contacted my reseller and got a new stepper with gear. I think it was free - not sure if I was lucky and still under warranty. Contact the biggest reseller in your country and they will want the serial number.

500 hours is not much. It's around when you need to change the teflon part. Expect to have to change that part every 500 hours. It's a consumable like filament. The um2 will be less hassle, less learning curve, and slightly better quality and make you happier but the um3 will be a little more flexible with the PVA option. More learning curve for the UM3 (e.g. how to dry PVA and keep it dry). More things that can go wrong. But both of these printers are workhorses that will work hard and for years. I use my um2 printers 95% of the time but when I need PVA support, it's nice to have available.

I find "hot" tap water is not hot enough. You want it around 60-80C (140-180F) which is like "tea" hot. I would boil water and pour into a lasagne pan or something big enough. The water doesn't need to be boiling when you immerse the bowden but if it *was* boiling then it will probably cool to 60-80C by the time it heats up the container that you pour the water into.

I can't see that very well. it could be underextrusion or it could be bad layer adhesion. ABS is tough to print. I recommend PLA for now. Unless you are patient and willing to spend a week or two figuring it out.

filament that sizzles and pops is indeed "wet". Probably only the outer few meters were affected. Dry ABS filament by putting it on the heated bed at 90C overnight with a towel over the spool. Don't do this high a temp with pla or pva. I've *never* had to dry pla. Not sure if it can absorb water. PVA gets soft around 80C so dry PVA at 70C. Nylon can be dried at 90C.

I prefer the one without the "T". It puts out quite a bit more power and that model has never failed me.

I've had a bad power brick and many people on the forum have mentioned issues with power bricks and I have a friend who had a bad power brick. so I'd definitely strongly conisder that. It could also be some kind of short - but if so then the bed probably wouldn't get warm. So I doubt that's an issue. If you are an electrical engineer you could cut open the power supply cable - insert a shunt resistor (around 0.1 ohms) and measure the actual current. But even I would probably just buy another supply. I use my "bad" supply for a um2go with a heated bed added. This works great because the um2go heated bed is only 60 watts (versus um2 160 watts I think). These supplies cost around $90 I believe (I probably got it on ebay or amazon).

yeah, that's underextrusion in the infill. What speeds were you printing at? Read my list linked to above. The "plus" feeder can print very fast. If you've printed over 500 hours on that printer (check in the menu system) then it's probably time to change the teflon part. I see them in my store at thegr5store.com but this is one of the most reasonably priced parts that Ultimaker sells so you could contact your reseller or fbrc8.com to get offical ultimaker parts.

Yeah sanding and body filler spray and bondo - that's a good solution but a LOT of work. I'm told you want to "wet sand" (make sure sand paper is wet) to keep things cool as PLA gets soft at 52C so you need to keep the sandpaper and plastic cool for best results. Acetone smoothing works quite well but you have to read a lot of that thread I linked to. You can't just use any PLA - you have to use certain brands. Basically I believe it needs to be "cheap" pla with fewer additives and the color can make a difference as well. Some people paint on acetone with a brush for more control. If you leave it in acetone too long the layers can separate making it quite ugly. I think you want thicker walls for this reason also. You can contact @cloakfiend directly - he's very helpful. He has youtube videos showing his process also. All in that thread/topic I linked to above. ABS acetone smoothing is much simpler and more consistent (but printing ABS is harder). You use acetone vapors. Typically you fill a paint can or other sealed container with just 1/4 inch of acetone and you put a metal tray above - such as a wire rack - or build something out of the lid of a tin can. Then put the part above in the vapors only. Then seal it up for 10 to 60 minutes. There's lots of youtube videos on this. PLA smoothing is more rare and needs a complete dunk into the acetone. polyfill is an interesting process as well as I mentioned.

Probably only when doing auto level. I don't know 100%.

3d printing gives you lines. Are you saying you don't like the lines? You can drop from 0.1mm layers to 0.06 layers but you'll still see the lines - they'll just be thinner. why are lines so bad? Some people like the look of the lines. It shows a little bit about the process. Like most people don't mind the grain in wood and in fact think it improves the look of wood items. Some people hate the grain of course. So you want those thin layer lines to go away? Well you could do acetone wash. It will shrink the part a bit but there is a process. YOu can't use ordinary PLA you have to use certain brands of filament. You should practice on many small parts first but this guy (cloakfiend) is the expert with PLA smoothing - watch some of his newer videos - there's many many pages to go through. I'd maybe read the first page of posts and then skip to the end and go backwards as over the years he improves on his techniques. https://ultimaker.com/en/community/10412-acetone-finishing-on-pla Or you could look into using polyfill and the polysmoother. Or you could do ABS and acetone vapor (but ABS is much more difficult to print - I recommend you stick with PLA or polyfill). Finally you can use "rough" filaments that make the lines pretty much invisible but the surface is rougher. It's pretty amazing, really. Let's see - ngen LUX comes to mind - amazing stuff - but you might not like the look - sparkly. CF filled filaments also tend to hide the layer lines.

I fixed the title for you.

must be a different problem as the previous poster used 4.1 and you found it works fine in 4.1. I'd look at the profile settings particularly those in the "mesh fixes" area. I think something is wrong with the model. You could send your model through the free netfabb web repair service (free but you have to create an account) and if that fixes the model it would prove that the issue is with the model.

titanx is ABS which as geert_2 says is difficult to print (but doable). It took me about 100 prints to get really good at PLA and then another 100 to get really good at ABS. You haven't started on the major issues with PLA yet (you will get there when you create an entire print). If I go above around 250C with ABS on a UM2 I have to print faster or it will clog. Be very careful - ABS creates nasty clogs if you leave the nozzle hot and ABS sits in the nozzle too long (like just a few minutes). ABS tends to be very weak so you have to set the fan very low to get good layer adhesion. ABS warps more so you need to cover the top of your printer and use ABS glue on the glass (or liquid PVA). But you haven't hit these issues yet so back to your problem... I don't see any holes. I see tiny bumps. Is this what you mean? I suspect that will go away if you go up a few more layers. It looks like slight overextrusion. You could try printing 90% extrusion (I see you mentioned going down to 96%). You can modify this live while printing from the TUNE menu. Could those bumps be particles? Maybe the material that makes the filament white? chalk? I find that white filament (pla, abs, CPE, whatever) is the hardest material to print. It doesn't behave as well.

There's 2 ways to fix this. One is to just turn off leveling. It's really a waste of your time as manual leveling is so simple and easy and you only have to do it when you swap out cores and usually not even then. If the nozzle levels too close usually it's because the spring in the core is weaker versus the spring in the bed. You need the core spring stronger because the leveling doesn't know you've hit the bed until it starts moving so if the core moves first then there is a problem. So loosen those 3 springs by turning the 3 knobs about 5 or 10 turns CCW (as seen from below). That might be too loose to level but try that first and do a manual level (mandatory if you move those screws that much) and then see if auto level is better after that. Don't loosen them too much. Another solution is to remove the "bad" core. Remove that one screw in the clear plastic part, take the spring out and stretch it such that it is about 5mm longer. Put it all back together and it will work great for another few years.

It depends what area you want to improve but my first advice is to use PLA which looks better and is stronger. In those photos those parts look 100% operfect - I can't see any defects. I think the photo is a bit underexposed. Note that shiny black filament shows up defects more than any other color. Flat black shows very little defects. If you must use shiny filament try a light color (but not white which is harder to print regardless of material). General advice for improving quality is to print at half speed. But it depends on your particular issue.

Oh and ohm out those 5 pads on your cores - I suspect a short between the center pad and either of the pads on either side (should be open). Or maybe the core just went in a bit crooked? Seems very unlikely. Unless you had a head flood and your whole head is warped just a little.