gr5

Well I'm not sure the Cura version of raft is worth it - I'm not sure the people who wrote Cura (mostly Daid) understood the purpose fully - it's from the days when people only printed ABS and before heated beds and I suspect Daid wrote this *after* that and didn't have a lot of raft experience. I say this because I don't think the raft is designed correctly in Cura. It needs to be very flexible - the raft needs to contact the bed say in horizontal lines - then connect to a new section of raft in vertical lines such that there are only tiny points of connection. Then connect to the part. I've never had to use raft. PLA never needs a raft and if you do the 4 things in my video you can print much more difficult materials like ABS, Nylon without a raft also.

Well first of all make your walls thicker - I see the infill showing through so assuming you have a 0.4mm nozzle then set line widths (all of them!) to 0.4mm and make the shell/wall 0.8 or 1.2mm thick. This looks like the walls is only 0.4 thick. Then if the infill still shows through there is a parameter to make it print the outside first (not the default). This can help quite a bit also. Most issues, 90% of issues, get better with slower speed so also try printing at 1/3 the speed you did for this print - just to see what happens. Think of it as an experiment. Most printers let you adjust print speed aka "feedrate %" on the fly while printing so you don't have to print an entire benchy if you are impatient. Finally I see some bad horizontal layers. This could be many thnings including a crappy quality printer or a dirty Z screw. For these types of printers quality usually improves if you make the layers thicker so if you were printing 0.1 then try 0.2. This will also cut your print time by the same ratio (e.g. 2X faster).

That looks pretty typical. I don't think anything is wrong with your BB core. PVA does not stick to itself while still molten as well as PLA. PLA comes out like a liquid rubber band while still hot. PVA comes out like toothpaste, or cement, where it doesn't stick to itself and tiny chunks can fall. You need to keep PVA super dry. No one seems to get this. You can't just put it in a bag with a little pack of dessicant. You have to keep it at like 10% humidity. Like a dessert. If you leave it on the back of your printer for 4 days it is "ruined" and needs drying again. I usually dry a spool of PVA on my heated bed with the temp set to 80C and with a towel over it overnight. Don't go over 80C or all your PVA will melt. But best to keep it dry with rechargable color changing dessicant. Look that up on ebay. You want boxes of dessicant the size of your fist. Roughly. The dessicant needs to be recharged often. That's why you need the color changing type to know how it's doing. If it gets wet then it sticks to itself even worse. If it gets VERY wet it makes sizzling noises while printing as you can hear the water boiling. Those steam bubbles get into the PVA and cause problems.

Don't worry - Gray ABS and generic ABS use the same profile with the same temperatures and other settings. Neither Cura, nor the printer need to know the color of the material. In real life, white pla and white abs do behave a little different but Ultimaker hasn't come up with profiles that change depending on color. Yet. I don't expect them to. At least not for PLA and ABS. By the way, ABS is not a great material - what are your needs that PLA wasn't good enough? Temperature? If you need a higher temp material consider CPE/PET or whatever people are calling it now. PET is easier to print the ABS. ABS is probably going to come out uglier and weaker without a lot of experimenting to get it right. PLA is so much easier.

johnse has great advice. But you shouldn't need a raft. Raft is an old technology and there are several newer generations of materials and printers since then. What kind of printer do you have? What material are you printing? You don't need raft with PLA. Ever. If you are printing ABS (don't print ABS) and you have a reprap style printer - like the prusa i3, then raft might be a good option. But if you have a printer with a heated bed you don't need raft. I talk about raft and the newer technologies - why they are needed - the purposes - and solutions - here:

I feel it usually takes 100 prints in a particular material to get good at it and I've only done about 7 PP prints. But I've done many high temp materials. Firstly it's usually good to enclose the top and front of the printer for high temp materials like PP. without doing this you will get weak layer adhesion and prints will break easily along layer lines. Also for the same reason lower the fan speed a lot - to about 1/3 the power (which may be 1% or may be 40% fan speed depending). Play with the fan speed until you figure out where the power starts to drop. On my UM3 it starts to drop around 10%. In other words 10% and 100% are identical but 9% is around 90% power and 3% is about right for high temp materials. On my S5 30% and 100% are the same speed and 10% is good for high temp materials. You should figure out what's a good reduced fan setting for each of your printers individually. Now the more serious problem - underextrusion so severe it sometimes stops printing (last photo above). Some materials clog easily especially if you print "too slow". So sometimes thicker layers (like say 0.2mm height) is less likely to clog than 0.1 because you get more plastic flowing so the plastic stays hot for less time. Check your feeder - with the material in question (PP this time) insert the filament half way down the bowden, then energize the stepper with "move material", then pull and fight that feeder. The feeder on a UM3 or S5 should be able to pull with about 15 pounds (8kg) force. Anything less than 10 pounds is a defective feeder and needs to be fixed right away. If the feeder is fine, in addition to trying thicker layers, try a different core. The nozzle may have some kind of issue. I probably wouldn't mess with nozzle temperature as UM is somewhat reasonable at making profiles with the right temperature (but I wouldn't trust them 100%). Here's a list of causes of underextrusion for UM3. CAUSES FOR UNDEREXTRUSION ON UM3 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) 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. Note that your "print speed" may be 40mm/sec but it may be printing infill at 80mm/sec so CHECK ALL SPEEDS. 2) Line Width larger than nozzle. In cura 3.X search in settings for all line widths. If any of them are larger than the nozzle diameter this can cause underextrusion. There are 8 of these in cura 3.2.1. 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) Bad core. Try a different core. It could be clogged, or something more complex like the temp sensor in the core. 5a) clogged nozzle - the number one most suspected problem of course. Sometimes a grain of sand gets in there but that's more obvious (it just won't print). Atomic method (cold pull) is the cure - from the menu do a few cold pulls. The result should be filament that is the exact shape of the interior of the nozzle including the tiny passage to the tip of the nozzle. If it doesn't look like that you need to pull at a colder temperature. You can do it manually instead of through the menu if it's not working right but learn through the menu initially. 95C is roughly the correct "cold" temperature for PLA. Higher temps for other filaments. Simpler cold pull (3dsolex cores only - doesn't work on ultimaker cores because you can't remove the nozzle): https://www.youtube.com/watch?v=u07m3HTNyEg 5b) 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 6) feeder spring issues - too tight, too loose. 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. You usually want the tension in the center. 7) 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. 😎 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 8b) 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 wedgebot (link below) helps you feel this with your hand by sliding the filament through the bowden a bit to see if it is stuck. https://www.youmagine.com/designs/wedgebot-for-ultimaker2 9) Extruder mis calibrated. Maybe you changed equipment or a wire fell off. Try commanding the filament to move exactly 100mm and then measureing with a ruler that it moved 100mm within 10% accuracy. If not adjust the steps/mm (this is done by editing a json file on the UM3). 10) Z axis steps/mm. it's easier than you might think to double or half the Z axis movement as there is a jumper on the circuit board that can be added or removed. If the Z axis is moving 2X you will get 50% underextrusion. Your parts will also be 2X as tall. 11) 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. Similar to 8b above - use the wedgebot to feel how much friction there is in the bowden. 12) 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 insert filament that has the pattern from the feeder and fight the movement by applying 2kg force on both ends at the same time and then seeing how much harder you have to push it on top of 1kg force. UM2 feeders can push with 5kg force. UM3 can push quite a bit more. 5kg is plenty. 13) 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. This shouldn't be a problem on the UM3 which has very good quality control but try a different core. 14) 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. 15) 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 - there is a temp sensor built into the driver chip. The solution from Ultimaker for the um2 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. This doesn't seem to be a problem on UM3 even though it's the exact same circuitry but they lowered the current in the firmware. But it's worth considering if air temp is 30C or hotter. It would probably happen only after printing for a while (air heats up slowly under the printer). 16) third fan broken. This tends to cause complete non-extrusion part way through a print. In the door of the head. You can hear it come on when cores get above 40C. 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. 17) 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 core 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. 18) 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). 19) 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. 20) 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 =======

The one from 3dsolex does, yes, because it's 0.5mm and also because it has no internal structure. But every manufacturer of nozzles has a different internal structure with different length of the final 0.4mm tunnel. More info in this video but this guy is sometimes amazingly stupid, but usually quite smart. He didn't notice that the channel is longer in the e3d version. I'm pretty sure the channel length is the key difference in this case in his video. Just watch for a few seconds starting at 12:28 (link should jump you to 12:28). But check out the internals of a 3dsolex "race" nozzle!:

You can get developers attentions better by posting this on the git issues page as a feature request: https://github.com/ultimaker/cura/issues/ Also if you can convince @smartavionics that this is worthwhile - he has made quite a few changes to cura recently (even though he doesn't work for Ultimaker).

There are definitely issues with older 3dsolex cores not seating well. There have been 4 changes to the cores to fix this. I'd like to send you a free refurbished replacement so you have a good one and so I can see if you have the latest version or not. A quick work around: The problem is worse in the right slot so one solution might be to swap slots - put the 3dsolex in the left slot and push gently forward on the nozzle block until the nozzle stops descending. If you push up on the nozzle and let go, the older 3dsolex cores don't go quite all the way down - push nozzle gently towards the rear of the printer and it goes down the rest of the way. At this point, as long as you don't remove the 3dsolex core - it will be fine for months. But if you have the latest core you don't need to do this workaround. Contact me at thegr5store@gmail to get a free replacement. Free shipping (both ways) as well.

The other reason that we want it thin is because the more mass is in the plate, the longer it takes to heat up and more importantly cool down. People don't want to wait 20 minutes for a massive aluminum plate to cool back to room temperature so they can get their part off without smushing it. But mostly one would want it to be easy to swap glass and aluminum and having them both fit the same clips would be nice. I suppose the aluminum could have slots cut out for the clips and be much thicker than the glass? Are you listening Ultimaker? That would be patentable!

We call this kind of "fir" stringing. stringing is a little bit of nozzle leakage in a straight line between two points that the nozzle moves between. "hair" is usually a strange phenomenon similar to cotton candy where extra thin hairs come out of "nowhere" and get blown around and find their way everywhere with no discernable pattern. Anyway, thanks for this post, it confirms some things I knew - basically internal geometry of the nozzle is important. More expensive brass nozzles usually string less - usually they have a more gradual slope going from 4mm or 2mm I.D. down to the typical 0.4mm I.D. The length of the final channel is important also. If it's too short then the nozzle leaks more. 3dsolex.com "race" nozzles seem to string not-at-all as far as I can tell - even the 0.8mm nozzles because of their complicated internal geometry. disclaimer: I sell 3dsolex products in USA at my store: thegr5store.com so I am biased.

It's really hard to tell what's going on from your images. The wall width should be defined in the CAD software by where you position the inner and outer edge of the wall in CAD. Cura doesn't normally mess with wall width but you can increase "horizontal expansion" which is a little hard to explain - an STL file is an unordered list of triangles. The slicer intersects them with the plane to slice next. This results in an unordered set of lines. Cura then tries to link the lines up into loops and then tries to figure out which side of each loop and it's lines are "inside" and which side is "outside". "horizontal expansion" moves all the lines away from the "inside". So if your wall is 1mm thick and you do 1mm horizontal expansion it moves the inner and outer part of the wall to make it now 3mm thick. This may fix your walls but mess up other things (make vertical holes smaller for example). Because your photos are so far zoomed out and because I don't know what the inside of your model is supposed to look like (I can mostly only see the outside) I don't know what is going on. Did you try xray view? If you don't see any red then netfabb probably won't be able to help.

First of all don't do 100% infill. It wastes time and filament and doesn't increase strength. Well it doesn't affect bending strength or pulling strength but it does help crushing strength (if you stand on the print - infill will help). wall-not-adhering is always an underextrusion issue. Because you had the problem the most with 100% infill then I'm guessing your infill printing speed is higher than your wall speed and the infill speed is too high where it's underextruding. But there are easily 20 possible causes for underextrusion. they are all "fixed" by slowing down. a lot. Try 4X or 8X slower. Just to see what happens. You should be able to adjust print speed on the fly. But even if that fixes it you may have a desire to print faster and there may be something you can do about that. I don't know. Yes you should absolutely get a cooling fan. Quality will increase. Particularly for overhangs. You want to cool the part without cooling the nozzle if possible. If you use a fan you have to worry about back pressure - most fan shrouds block flow too much and the fan is useless. Blowers don't mind back pressure.

Those strings on the side don't have a lot to do with the filament. Those happen on filament changes when changing from PVA back to PLA. The old nozzle is leaking a bit and there is this little string/noodle sticking out of the nozzle and when it starts printing again it gets attached to the side of the print. One solution is a prime tower. There is an option in cura to add a prime tower. Make sure the prime tower isn't in a rear corner - it does better in the rear center if possible.

The 3rd photo - support "touching buildplate" is probably what you want - I'd try that first. You don't need support for those things that stick out. Okay so your model isn't solid. What CAD software did you use? Try passing it through this netfab repair service: https://service.netfabb.com/login.php You have to create an account but it will repair your STL for free. Also try viewing your part in "xray" mode. (top selection "preview mode" left selection "x-ray view"). blue and white areas are good. Red areas are a problem. For example if your walls are infinitely thin then it will print nothing (infinitely thin is nothing in 3 dimensions). Or if your walls are < line width *2 it may also print nothing. So if your line width is 0.4 you want the walls at least 0.8. You can also select the checkbox "print thin walls" which let's you go down to around 0.4mm thick walls I think. how thick are your walls?

Yeah, calibration procedure it says to push it in firmly but then I back it out by maybe 1mm to the left before setting the position.

So that ruby core you bought - it's meant for the Ultimaker 2. I don't know if you got the Olsson ruby or the 3dsolex everlast but I can tell in the picture that it has standard M6 thread and it's meant for the UM2 printer only. For the UM3 or S5 you have 2 choices. You can by a CC 0.6 core from the same manufacturer that sold you your printer. Or you can buy a 3dsolex "hardcore" with a ruby nozzle. 3dsolex.com. disclaimer: In the USA I sell 3dsolex parts (thegr5store.com)

I'm not sure but I think there were issues of inconsistent flatness and possibly the aluminum warps over time after heating to 100C and cooling again repeatedly. Or maybe only the *second* issue (the temperature warping) was the issue. Note that it's pretty thin - probably the same thickness as the glass which you could measure yourself but I think might be 4mm? Making aluminum that thin and also having it not warp when repeatedly heated to 100C is evidently a problem.

I don't see any stringing - or barely any. Your retraction looks good. Maybe what I call "bridging" you call "stringing"? Bridging is where you are bridging across an air gap. Yes your part doesn't look great there but that's probably the best you can get with Nylon alone. If you had a dual nozzle printer, PVA works very well with Nylon. But I can't help you on the bridge settings - PLA is the nicest material for bridging and even PLA won't get much better than what you got. Usually. Although @smartavionics has a version of Cura that lets you play with a lot of the bridge settings. You could try that version of Cura - search for "bridge" in the settings. https://www.dropbox.com/sh/s43vqzmi4d2bqe2/AAADdYdSu9iwcKa0Knqgurm4a?dl=0&lst=

Not sure what's causing these issues but try printing at half speed and also at 1/4 speed for a few layers - just to see what happens. Your printer should allow you to set feedrate at 50% while printing. And then also try 25%. With PLA 240C works but not if you want nice looking prints. Stick to closer to 210C or even 195C. Every printer is different so I can't say what temp is best.

That's called pillowing sometimes although it's so extreme I don't know what to call it in this case but it's the same issue lots of fan. maximum possible fan thicker layers. 0.2 layers will fill top better but not mandatory thick skin - 8 layers (1.6mm thick of 0.2 layers) will cover better - each layer gets better so after 8 layers of this it should look pretty good print slower - I get that at speeds of over 200mm/sec but I assume you are printing much slower. The point is slower is better.

This topic is 6 years old. Please start a new topic - especially since you don't have the problem mentioned here. No one is going to notice your post here if they follow recent posts and topics. Please also post a picture of your part in PREPARE view in cura and also PREVIEW view in cura to show what you are talking about. I do better with pictures versus words.

If wall isn't attaching it's still underextruding somewhat. I have a lot of thoughts. 1) Pay attention to if it prints outermost wall first or last. You probably want "last" which is I think default in most profiles. 2) You can play with line width. I think it defaults to 0.4 for most 0.4mm nozzle profiles but you can set it to 0.35 for example and it will print the lines .35mm apart instead of .4mm apart but will underextrude correspondingly. Then you can increase flow by 0.4/0.3 or 14% (flow at 114%) and you will be extruding .4mm lines .35mm apart. Not recommended but will work. You may get too much overextrusion in most places. 3) Keep slowing it down. 4) You say 40mm/sec and 50mm/sec in posts above but are *all* speeds the same? Typically the outer and inner shells are printed at a different speed than the infill. Try to make *all* the printing speeds the same (leave travel speed fast, leave first layer slow) 5) Ender has a TUNE menu where you can set the feedrate to 50% to see if that helps - you can experiment with temperature, flow and feedrate on each layer and keep notes and realize what speed and temp is best to get zero underextrusion. 6) Everyone thinks the oil will mess something up. It won't. Try it. It works wonders at least on bowden printers. Not sure if your ender is a bowden printer. 7) Normally going over 110% is a really bad idea - at least for PLA - but for these flexible filaments it might be okay. At some point if you have the flow too high it will bunch up and tangle all up inside the feeder. #8 - Cheetah is also considered an "easy to print" flexible filament. Because it's stiffer than ninjaflex. These are still not as easy as PLA.

The problem is underextrusion. What kind of printer did you use? If it's a bowden printer like an Ultimaker you need to oil the filament. Put a drop of oil on the filament before inserting it. The oil will not affect the print in any way. Really. Add another drop every meter or so. You many need to slow the print further. Maybe down to 10mm/sec. These 2 things - oil and speed are probably enough. You may need to increase the temp as high as 240C. It depends on which filament you are using exactly.

I built foehnsturms flow sensor myself - one of the earlier versions. I cast the rubber wheels also. I found it to be very finicky and sensitive. The friction was usually tiny but sometimes there would be just enough friction for the gears to get stuck. The tiny gears were 3d printed and meshed pretty well but not quite good enough. Having the tolerances in the gears and axles be slightly too tight or slightly too loose would cause them to get stuck. Remove the flow sensor from your printer. Cut 20cm of filament and push it through the sensor back and forth. Twist the filament at the same time. Add some pressure. watch the gears. Give it lateral pressure in the direction expected when feeding from a spool off to the side on the back of the printer. Do the flow sensor wheels sometimes get stuck? If so that needs to be fixed. Maybe take it apart and try to find the problem. Maybe use a file or something to improve the parts. By the way - note that it worked fine most of the time. I got through a few prints without a single problem. But then other prints had the issue you describe because the wheels would stop turning.