Cura Quality Hints for Better 3d Printing

hi this is herb shepard with the dr vax channel and today we're going to look at how to go from this really relatively ugly print i'm not sure you can see because it's printed in white how ugly it is but there are clear layer lines there's an enormous amount of ghosting there's this terrible seam right here right across the front uh the back is fair but more ghosting and artifacts and then i have this version where there is no seam at all on the front it's much harder to see the lariat lines there's a little bit of ghosting where i go from the transition of printing two object areas to one or from here to here but overall this is quite a beautiful print so today we're going to learn how to go from one to the other and if you want to learn both the concepts involved and the particular cura settings then stay tuned and let's learn something together now before we get started don't forget to subscribe to the channel and click on the bell share these videos with everyone you know because that helps the channel and inspires me to produce lots of additional videos where my goal is to simplify technology concepts so more and more people can use technology to make things when talking about quality and 3d printing i'm reminded about a classical philosophical concepts that and this concept is described both by confucius and by aristotle i'm going to use an example from aristotle's representation of this concept it's called the doctrine of the mean now aristotle uses it to describe the idea of balance in becoming a virtuous human being but i'm going to take his example and then apply it to 3d printing the example that aristotle gives is that of a soldier in a war if the soldier has too much courage then perhaps they'll take risks they'll make bad decisions and they'll die if the soldier has too little courage they'll be a coward they'll run away from the battle and face repercussions so a soldier needs the right amount the right balance of courage in the case of 3d printing if you want the very best quality it's going to take longer so this print was a six hour print this print was a three hour print but even more so there's a third concept that applies and that's to strength the more plastic in the case of fdm printers that you lay down as part of a print the stronger it'll be as an example many of you may have printed a model in vase mode in vase mode you're telling the slicer to create a print where there's only a single layer of plastic those prints are quite beautiful they print very very fast they're very very weak this model i can't really flex very much a little bit but not very much this was printed in traditional mode if this had been printed in vase mode i could have easily bent this model so on the one hand we have quality as you raise up quality you're going to lower your speed and potentially reduce the strength of your model now let's look at this slide for a second there are two phrases on this slide filament flow and nozzle positioning everything's summed up and there are many many parameters in cura but everything sums up to these two concepts the smoother the flow of your filament the more continuous the flow of your filament the more consistent the flow of your filament the higher quality print you obtain that combines with the ability to move the printhead to a precise location and while the printhead is moving ideally you want no filament flow filament flow while the printhead is moving causes stringing so our ability to control these two characteristics of your 3d printer will go a long ways towards determining the quality of your print and in the future as you look through 100 plus parameters in your favorite slicer think about the impact on filament flow and positioning now if i break down the key parameters we're going to look at today i can divide them across these two categories so the area of filament flow i have layer height temperature speed travel retraction and combing now in fact some of these parameters impact both because in terms of positioning the first item is speed the faster you ask your printer to move the more likely there'll be vibration in your frame vibration on the table it's sitting on the inability of the printer to precisely place the nozzle where you want it the faster you attempt to print and this is not obvious to a lot of people the more difficulty your printer your 3d printer will have in extruding a precise amount of filament likewise for positioning you have travel retraction combing once again build plate adhesion well this also might not be obvious but when you think about it if your print moves at all on that build plate you're not going to be able to precisely position that print one reason for significant layer shifts which cause lines in your print is both the ability of your printer to manipulate the build plate properly but also if your print is not solid on that build plate we're going to look specifically about how to eliminate these scenes and the impact both on slicer settings and on model orientation and we're going to look at a mesh fix parameter a parameter a lot of people may not know about that will help your printer print more smoothly by printing less small segments if your printer has to print very small segments every time you have to reposition that nozzle it makes it harder for your printer to extrude a smooth line of filament now let's look at this next picture and understand a little bit about how 3d printers work and this might be a review for a lot of you but once again thinking about the mechanics will help you set your slicer parameters more precisely on the left side of this picture we have a bowden style 3d printer so you have a roll of filament the extruder pulls the filament off that roll or reel of filament it pushes it through a long tube called a bowden tube into the hot end now let's look at that hot end a little bit the green section of that hot end includes both a thermistor that will measure temperature and a heating element and that's where the filament is actually softened or close to melting that softened or melted filament is pushed into the nozzle the black area with fins above the heating element is called the heat break because if we have soft or melted filament moving back into the bowden tube we won't be able to control extrusion properly so you want the filament soft in the green area and below and not soft above that now if we are printing faster the extruder has to turn faster it has to push filament into that hot zone it has to melt and come out the nozzle the ability to melt the filament is dependent on both the volume of filament pushed into that hot zone and the temperature of that hot area so if we want to print faster we may want to increase our temperature but if we increase our temperature when the filament comes out the nozzle at the end it's going to be hotter it's going to take longer to cool off and it's going to cause more stringing we're back to the doctrine of the mean on the right side you'll see a direct extruder printer which has the advantage that it does not have that bowden tube the extruder pushes the filament directly through the heat break into the hot end and so there's more precise control and in general direct extruder printers are often faster now that's interesting because there's more weight being moved around because the extruder's on top of the hot end versus being somewhere off on the side but in general at least in my experiences my prusa my quitti and my ultimate 2 monopolies ultimate 2 are all faster than some of my other printers now in addition to the parameters we're going to concentrate on there's a whole range of parameters that directly impact the flow of your filament cura assumes if it tells the printer to extrude x volume of filament that's exactly what's going to happen it assumes every printer is in essence perfect but they're not and they're not even close now there are a couple ways to attune the extrusion of filament the primary areas that you're going to tune are the ability of your printer to hold temperature that's called pid tuning there are videos on the channel about that in addition to tuning temperature it's also important to tune the extruder how much should it turn each time it needs to extrude filament now you can tune that in the firmware itself and there's a video on the channel on that but you can compensate for an imprecise extruder by just changing values in your slicer so on the screen here you'll see that you can set the overall flow rate the wall flow rate the infill the skirt the top bottom flow rates if you make this number bigger then your slicer will attempt to compensate for an imperfect extruder by pushing out more filament if you make it smaller it will push out less filament now how do you determine what to do well you take a model this is called a calibration cat there are many calibration models available on the web i'll provide a link to this one and this is supposed to be exactly 20 millimeters by 20 millimeters so you print one and then you take either a ruler or a caliper obviously a caliber will be more accurate and you can see here it's somewhere between 19.8 and 19.9 millimeters on this side pretty darn good and on this side it's also about 19.8 now if this is off by more than of let's say five or ten percent you should probably change the extruder flow percentages in your slicer let me show you the formula for figuring that out so you'll see on this screen you take the expected measurement in our case here that's 20 millimeters you divide it by the actual measurement you multiply it by the current extruder multiplier that'll generally start at 100 and when you solve this algebraic equation and i know algebra is scary to some people it was scary to me for many years but then i married a woman with a master's in math so i had to learn algebra to survive our marriage when you solve this problem you'll see that it comes up with 108 in this set of examples so i'd fill in 108 as the top number if you look at this slide overall flow now i might want to fine-tune the other independent values that's probably a discussion beyond this video so now assuming you've checked your flow rate let's look at the other parameters right in cura and discuss how i would adjust those to go from this model with a terrible seam and lots of defects to this model which is really quite good now if you look at the screen this is what cura will look like if you first open it up you have no ability really to tune anything other than to set your layer height and your infill percentages so the first thing i'm going to want you to do is click on custom now that's going to show you more or less parameters depending on another very important setting so the next thing i'm going to do is click here and click on all that will allow me to see every parameter in cura now yes there's a lot of parameters in cura but they all really relate to controlling flow and positioning and let's get to it we're going to start with quality the first difference between these two models is this model because i wanted to print very fast was printed at a 0.3 millimeter layer height this was printed at a point one six millimeter layer height now why does that affect quality well higher layers fewer layers but you'll see them more but as importantly it means your printer has to extrude more filament the more filament over a given amount of time you ask your printer to extrude the more likely your quality is going to suffer however this particular model did print very fast it's printed in three hours this took double the time so the first thing i did is i reduced the layer height i made no change to infill i left it at 15 percent that might seem uh light but this doesn't have to be very strong it's just used to hold a remote control that i then velcro to the wall behind my bed so 15 worked just fine material i initially printed this first one at 190 degrees celsius because i find that on this particular printer this is a quiddix smart which is a middle grade printer not the best printer i have not the worst in some ways i really like it it's easy to use it does string a little bit at higher temperatures i looked at this model and there's not a lot of possibilities for stringing so i increased that to 200 degrees why it'll make it easier on the extruder to push filament through the melt zone next this fast print was printed at a hundred millimeters per second now acceleration and jerk control will actually impact that so i'm not going to get a 200 millimeters per second but i wanted this to print fast and it looks like i printed it fast this one was dropped down to 60 millimeters per second i find generally printing at 30 to 40 millimeters per second is the highest quality speed i can get out of any given printer travel you need to make sure retraction is on for quality you need to fine tune your retraction in order to minimize stringing i had no stringing at all on this print and so retraction is properly tuned here now in addition there's a parameter down here called combing now if you're on the current version of cura you don't really have to mess with this the default now is not in skin what combing does is when you go to print and then stop and travel to another spot to print you normally do a retraction you reduce the pressure on the nozzle by pulling back a little bit of filament now it's not actually going to pull filament out of the nozzle that's melted but it's going to reduce the pressure however that takes time now on a direct extruder printer like this one like the quiddy x smart probably not going to reduce a lot of time because you're only retracting about one 1.5 millimeters on a bowden style printer let's say an ender 3 ender 3 version 2 you might be retracting 5 6 7 millimeters it's going to take time so combing says when i'm moving inside the model in a place that i've already printed where it's going to be in the infill i'm not going to see it don't bother retracting i don't care if they're stringing the problem with that is as you get close to the top of your model if you have those strings under the top surface of your model it will cause a little bit of bumps you'll be able to see it i'll show you a picture of that here if you say combing not in skin that says retract even if you're printing over an area already printed if you're close to the top the outside the skin of the model and that'll improve your print quality next and i skipped over support because that's another topic that has to do with overhangs many of you have watched other videos about that there's a lot of good material on youtube about that including in my channel build plate adhesion you want to make sure this doesn't move at all so if i'm printing something really critical with a small surface area this has a pretty big surface area i will turn on a brim now there are really three options here there's skirt brim raft a skirt is just a line around the outside to start your printer flowing the filament properly a brim is actually a lip printed around your print that will help hold it to the print bed there's nothing right underneath but it's right up against the edge and it sort of forms a lip around it that's the option i normally select a raft is actually print something a flat surface underneath it put your print on top of that the problem with wraps is sometimes they're a little harder to remove so build plate adhesion is important next let's go down the mesh fixes and i'm going to put a picture on the screen because we're going to look at maximum resolution and maximum deviation 3d printers cannot print circles they always print line segments line segments might be very very small almost dots but they're printing dots and line segments to form a curve the more segments it prints the smoother the curve but the smaller the segments the more your printer has to work to position for all those positions each time it repositions it potentially could leave a bump i'll show you a picture here of a terrible example of a very bumpy print that i solved by changing the number of segments the way you change the number of segments is you set maximum resolution to a larger number the default is i believe something like 0.5 it used to be 0.15 in earlier versions of cura i often change it to one millimeter when i ask kira to use longer segments by setting maximum resolution higher i have a way to say to kira don't do it if it's really going to change the shape and that is i have cura measure the deviation from the original shape and if that deviation is larger the maximum deviation then it won't make this optimization so if we go back to here we'll see that i have a maximum deviation of 0.05 and a maximum resolution of 1. those changes taken together allowed me to go from this print to this print with one other important change let's look at scene so i'm going to go up here to the search box and type in seam and we can see seam alignment seam position seam position is set to the back now that would be a good idea because you don't want to seam on the front in this particular case i'm taking and attaching it with velcro to a wall or to my nightstand i wouldn't see a seam at all on the back in fact seam was already set to back when this first one was printed so let's look at what's going on here so i have here my model i'm going to take and slice it and it'll take just a moment or two and you'll see that with these settings it'll take 6 hours and 31 minutes let me look at the preview here now you'll see it's going to go around and start printing and see where the green line started it's going to come back to that spot each time that pause that spot where the green line was positioned is this seam right here and i don't know if you can see it but it's a very pronounced seam now i showed you earlier that i told cura to put the seam on the back why is the seam going there now you're looking at kira from the front and you'll see that this is what kira thinks is the front so kira didn't know that that's going to attach to a wall it thought this was the back so what i want to do here is i'm going to go to rotate and i'm going to rotate this around 180 degrees there we go now the back is truly the back so let's re-slice this go to preview and now we'll see it's starting the outer perimeter in the back on this side so the solution to this problem was actually not changing where cure was going to put the seam because i already had it set to back it was reorienting the model well folks i hope you learned something today you learned that you can print beautiful models on pretty much any 3d printer by adjusting parameters increasing temperature a little bit and slowing it down or you can print fast models by increasing the speed increasing the layer height thanks so much for watching if you enjoyed this give me a thumbs up subscribe to the channel most importantly if you want to discuss these concepts or others there's a group of almost a thousand viewers of my videos at forum.drvax.com and they talk about all of you videos after i publish them and they more importantly it's just a really good group of people that help each other out so go to forum.doctorvax.com and let's continue to learn things together

Channel: Make With Tech (MakeWithTech)

Views: 47,855

Keywords: 3d printer, 3d printers, 3d printers for beginners, 3d printing, 3d printing for beginners, 3d printing hints, 3d printing videos, getting started with 3d printing, how to 3d print, prusa slicer 2.0, prusaslicer, prusaslicer 2.0, simplify3d, slicer hints, slicer tips, what is 3d printing, what is 3d printing technology, what is 3d printing video, cura 4.8, cura mesh fixes resolution, cura layer height settings, cura flow, cura flow rate calibration, Make With Tech

Id: LNDgg5JNH3Y

Length: 27min 9sec (1629 seconds)

Published: Mon Jan 18 2021