Your Part Cooling Probably Sucks - feat. Hero Me

your part cooling probably looks like [Music] this meanwhile the 3D printer she told you not to worry about is printing like this [Music] wait part cooling is one of the most overlooked parts of a quality 3D printer and I also think it's oversimplified it's not just blowing as much air as you can onto a part today we're going to be taking a look at why part cooling is more complicated than you thought how to get the best part cooling possible right now and how to tune your part cooling to get the best possible [Music] results before we can talk about the complexities of part cooling we need to understand what part cooling is why part cooling is and how part cooling is part cooling is the cooling of plastic as it comes out of the nozzle of your 3D printer this is usually done by directing cool air towards the area underneath your nozzle so yeah the what is simple enough but how do we get part cooling the most common method is to attach a fan to your print head which blows air through a duct that directs the air just under the nozzle of your printer there are a lot of different ways to go about implementing this simple solution and we'll be taking a look at one great way in this video however there are two other part cooling methods which you may or may not be aware of the first is typically referred to as auxiliary part cooling this is where fand ducks are mounted to a part of the printer that isn't your print head say the x-axis Gantry on a bed Slinger or just to the side of the printer the advantage of this is that you can fit much larger more powerful fans to blow air through the ducks that you wouldn't be able to fit on your print head this is used in cases where extreme cooling is needed typically in high-speed printing the downside of these stationary part cooling Ducks is that they can only blow on one specific area of the printer the ones mounted to the Gantry that can move up and down with the print head are better but the ones that are mounted to the frame of the printer are kind of onetick ponies the last method is kind of a hybrid of the first two that I described it's where you have a very powerful fan or blower off the printer and it blows air through some kind of hose that attaches to the print head and then that air is directed to just under the part so it's great because you still get part cooling right under the nozzle all the time but you do have a larger hose directing air in again this is only really used when you need some extreme part cooling like in speed printing so we've got the what and the how of part cooling so why part cooling let's jump into a slicer to check out what's happening when we actually 3D print things our slicers tell our printers to extrude these lines which are about 0.4 mm wide and 0.2 mm tall and as our printer goes around just extrudes that line the thing is when our Plastics are extruded they're still molten they're not perfectly solid they're amorphous solids so you see this line path is extruded over pretty much just thin air and if that's not cooled then it's going to be again an amorphous solid which means it won't be completely rigid and stiff it will continue to flow sort of like a liquid um but it'll Bend and then when it cools it will finally solidify this changing of shape occurs for two main reasons the first most obvious one is gravity if there is nothing below the plastic being extruded as in the case of bridges and more steep overhangs then the plastic is just going to droop until it cools and hardens another reason is that as our Plastics cool they tend to contract this isn't really a problem for pla but in the case of abs and things like nylon those Plastics when they cool and contract they can often peel off the build plate or just morph the part I printed this Beni out with no part cooling active and you can see the hole actually has this concave bit from where the plastic contracted and pulled in the final main reason is that all the plastic you extrude is connected so think as you lay down a bit of plastic this nozzle is still pulling on the plastic that's been laid down and this plastic that's been laid down is still pulling on the plastic from the nozzle this is particularly important when a printer is making Corners if the plastic doesn't cool fast enough as that nozzle Corners it will pull the plastic with it all three of these issues can be mitigated by good part cooling so the ideal part cooling would be one that cools the plastic as fast as is possible well not exactly if you're only printing out artistic models like this Beni or this cool do decahedron model then you probably do just want to Blast Your Parts with part cooling but if you're interested in printing functional parts or printing with different Plastics other than just pla then you need to approach part cooling with more Nuance to explain why we need to understand a few things first so there's this property of plastics called the glass transition temperature the glass transition temperature is the temperature at which the molecules inside of our Plastics go from being mobile to being frozen in place this change in Mobility is what causes Plastics to melt and Harden for pla that temperature is about 60 C but the story still isn't just as simple as our Plastics going from molten to solid right when it passes that temperature in fact something I'd love to do a deep dive into in a future video is that actually how long a plastic takes to cool vastly changes its mechanical properties once it is cooled a simple analogy for this is like a blacksmith that is just Smith The Sword and it's still red hot usually they dip The Sword in water to cool it extremely quick well that sword is going to have different properties than a sword that was set down and just cooled in the air slowly to understand why the mechanical properties change depending on how our Plastics are cooled we need to take a step back and look at the chemistry of our Plastics the Plastics we use are made up of polymers polymers are long chains of identical units called monomers this is a pla monomer these monomers are chained together with very strong bonds ideally our plastic could just be one long polymer chain because it has such strong bonds between the monomers but that would be incredibly thin so what our Plastics actually are are just a bunch of these polymer chains just kind of stacked with each other in like this big glob but there aren't very strong bonds that hold one polymer chain to another the forces that are holding our polymer chains together aren't really strong chemical bonds like the ones holding the monomers together but they're weaker bonds one of them you might know is referred to as hydrogen bonding the other is a very weak Force called the Vander wals Force so when we heat up our Plastics beyond their glass transition temperature these bonds break and that's why all these polymers become mobile when we cool our Plastics below the glass transition temperature these bonds reform but there's a small range of temperature in here where the molecules are still sort of mobile but what they're doing is they're kind of reorienting themselves and forming these bonds this is why part cooling is an important consideration when it comes to the mechanical properties of our Plastics if we cool our Plastics too fast and we don't give the polymers time to reorient themselves then they won't make as many of these bonds between the polymers leading to basically different mechanical properties for plastic parts but if we keep our plastic at that certain temperature range where they can still freely make those bonds then we'll have stronger parts so let's extend this logic to 3D printing a huge issue with part strength is the actual interlayer adhesion between the layers that we lay down think about we've already laid down a layer of plastic and now we're laying another one on top that other layer has probably cooled past its glass transition temperature already so the layer added on top isn't going to get to form all these hydrogen bonds or Orient self Orient itself in a way that can effectively you know get the most bonds between the the two layers and remember there are no chemical bonds in the Z Direction they're only in the X and Y Direction so if you've heard of a process called analing This is basically a method to circumvent this issue analing is where you raise the temperature of something whether it's plastic or metal or whatever to a certain temperature and you leave it there for a few hours and this basically gives the material time to reorient itself form different crystallin structures usually you're doing this to change the mechanical property of the material in the case of pla we're raising the temperature to a point where the pla doesn't melt into a big heap of plastic but the molecules can reorient themselves and form these stronger bonds especially in between the different layers so what I want to do with part cooling is cool at a point where we're basically cooling as little as possible to still maintain the shape that we are laying down this will ensure that we're still creating the part that we see in our slicer and not just a big heap of plastic but it'll also ensure that the part cools slower giving us stronger Parts two things you can do besides changing your part cooling is just to print hotter and slower you can also print inside of an enclosure while using part Cooling and this will basically make it so that the cooling is less efficient if that makes sense um you're basic you're still cooling that large like 200 to 60 Cel very quickly but getting from like 60 C to 40 C takes a lot longer so for Plastics like ABS ASA and nylon you really do need an enclosure if you don't use one you're going to get very brittle parts so I know I took a few detours but the point I'm trying to get across is that there's no one size fits all for part cooling you really shouldn't approach part cooling just setting it at one speed and forgetting about it I think the material science behind Plastics is really cool and I would love to do a deeper dive into that in future videos so if you want to see that stick around the channel so we talked about why part cooling might be more complicated than you've approached it before but now let's talk about how we can get the best part [Music] cooling so when I say we're going to talk about how to get the best part cooling I'm kind of talking about Everyday Use cases nothing insane like those cpat machines that cool your parts today I'll be talking about a relatively simple method that can help you get some extreme bridging and overhangs done if you've seen my video where I tricked out my print head then you're already familiar with today's Park cooling it's the hero me system by medium Man 3d also known as Andy while it's mainly marketed as a park cooling upgrade thanks to these ducts that optimize air flow through them these days the homi system is really a lot more than just part cooling the current seventh generation of the homi part cooling system is basically a collection of parts that you can put together in a legol like fashion so if you're planning to stick with the stock Parts on your printer or if you want to get the best parts money can buy there are going to be parts to put all those together you can also easily add cool things like these neopixels while I personally love the ham me system there are a few things you should consider before you make the upgrade before we get any further I want to point you towards Andy's patreon page on that patreon page he's got something like a 50 60 page guide that shows you how to put this all together he has videos showing you how to orient and support the parts and you can even get your hands on a magnetic version of the printer so if you want to swap Parts out quickly you can do that you can get all that for cheaper than a new role of pla he's put thousands of hours into this project so go support him if you decide to get it so this part of the video is really only going to be an overview of the part cooling system and not like a step-by-step guide I'm also going to touch on some of the pros and cons of the system and talk about something that I think Andy kind of gets wrong about it but before we jump into the project let's talk about what you will need to make this upgrade the first is obvious and that would be some filament since we're printing functional parts that are going to hold your print head together you're going to want a high temperature plastic that is also very rigid I recommend using ASA because it has both of these properties and it's also much lighter than other Plastics like PLA and PG because it has a lower density you can get by with something like pla plus but you'll be limited in how you can print the other thing you cannot Overlook is a silicone sock for your hotend if you don't know already this is just a small piece of silicone that goes around your hotend and basically prevents air from hitting it cooling it down if you install the homi part cooling without this silicone sock basically the cooling is so efficient that it cools down the heater block so fast that your printer throws a thermal runaway warning you'll also need some PTFE tubing you'll only really need a small section and we'll get into why that is later in the video the last thing you'll need is a soldering iron no you're not going to need to do any soldering for this video but you'll need to use heat inserts if you're not already familiar with these they're the little knurled brass inserts that you can screw screws into but what you do is you use a soldering iron to press them into the plastic so that you can carefully melt the plastic around them they make for a really professional look and a very strong way to bind Parts together with screws but you do need something to melt them in place if you're on the market for a soldering iron I got this one off Amazon it cost me about $60 or three spools of pla I think it's a clone of a more high-end soldering iron but it hasn't failed me once in the last 3 years I'll even a link to that and all the other things I use in this video down in the description so let's jump right into it the first step is to download the repository from any of the big 3D printing model repositories on the internet I typically use printables dcom it's azip file that contains all of the parts that have been designed for the system all the official Parts there are lots of other parts that aren't part of the official system that other people have created for their specific use cases so if you can't find a part you need at any point then search the internet you'll probably find someone that had a similar situation after you've got the repository downloaded you're going to need to extract all the files to another folder that's because this is a compressed folder and then we want to select the parts that we want to print out and use for our print head in my opinion this is the most difficult part of the whole project there are so many parts in fact they claim that there's like 35 billion combinations that's one of like the the marketing things the issue is the parts don't really come with a good description I highly recommend purchasing the like 60-page guide on this from Andy even then it can still be a bit difficult so for most of the parts we're going to print out I highly recommend choosing a few of them and printing out a few different kind of versions of it because more than likely the first one you choose isn't going to work right off the bat and it's much nicer to just have them all printed out so you don't have to stop the project and wait on a print the first part you need is the Gantry adapter this is basically the part that translates whatever language your printer speaks to the hero me language I printed two different versions for my any cubic Viper and I also printed this version that lets you mount your tool head to a linear rail is that a hint for a future video seems like it so the part that the Gantry adapter connects to is called the universal base and this is a part that everyone is going to need to print the universal base is the Cornerstone of the homi system this is the part to which all the other parts connect to on top of our Universal base goes the next part our hotend mount so the Hoten Mount is basically what you attach your Hoten to and then you connect it to this and yeah Legos in this video I'll be using the mosquito Hoten from slice engineering if you want to support the channel I've got a link in the description to the slice engineering website if you choose to buy anything off of there then it'll support the channel the next part isn't one I've used before but it's called a skirt like the hotend mount it's Unique to your hotend it basically separates the air flow from your hot-end fan cooling down the hotend heat sink from the actual heater block so you don't cool that down it also adds places to mount things like an adxl or an accelerometer or things like neopixels which is what I chose to do in this video if you're planning to run a direct drive setup like I do then the next thing you'll need is an extruder [Music] Mount the extruder Mount basically pops on top of your hotend Mount I'll be using the Orbiter V2 the next part is probably the most iconic part of the system and and it is the actual part cooling ducts now there are a few different orientations of this there are some that connect both fans together there's some for dual fans different size fans single fans there's one for a CPAP hose again print a few out depending on what you're going with the last big part is the amount for your bed Leveling [Music] Sensor this is actually two separate parts and it's designed this way so that you can get the optimal configuration for your bed Leveling Sensor if you didn't print out multiple versions of anything else please print out multiple versions of this you're going to need it the goal is to pretty much get your bed Leveling Sensor as close to the hotend or the rest of the print head so it's Compact and looks good now after you've printed out all the main components there are a bunch of other things you can print out like cable management Towers to help tidy up your wiring there are oscope mounts LED mounts adxl mounts just explore what's out there so now that we've got all our parts selected it's time to start adding heat inserts and test fitting Parts together starting with the universal base you'll be wanting to add heat inserts just about everywhere the first four to add depend on your Gantry adapter they either go on the side of the universal base or on the back of it for instance the Viper adapter I've printed out uses the four on the sides while the linear Carriage adapter uses the four on the back next are the heat inserts for the fan ducts to be mounted there are two inserts on top for your hot-end Mount and your extruder Mount four inserts on the front to mount a hot-end cooling fan and finally there are two on the bottom if you're going to use a skirt after you add heat inserts to the base it's good to start test fitting parts that you've selected to see what's going to work for you [Music] after you get your Extrusion system assembled this is where you need to add the PTFE tubing this basically guides filament from your extruder down to your hot end I forgot to do that until I mounted the print head so I'm going to skip ahead a bit but don't forget that also I always find that the holes that the PTFE tubing is supposed to go into are a bit too narrow from the printing so I always have to widen them with a drill I think I used an 8 in drill bit and that works really well it still lets the PTFE have a a good fit so it doesn't slide around but you know it fits basically cut a section that's longer than you need and then keep putting the extruder on top and cutting off small bits at a time until it fits together perfectly it's kind of like a haircut you you can keep cutting hair off but you can't put it back on after that I got to work on the part cooling ducks at first I printed out this set that had a brace between the too because I thought it would make for a more rigid setup it also had a place for heat inserts here so that you didn't have to use um nuts with the screws unfortunately while I was adding those heat inserts the actual spot that you mount the fan snapped there's that weak interlayer adhesion I talked about so I tried to print another set out at a hotter temperature and at a slower speed thinking that that might make it better but I tried again and it snapped oh son of a gun not again you okay yeah my freaking thing broke basically this is what happens when you print ASA on an unenclosed printer like I did all the thicker Parts seem strong enough but it was just these thin bits were too thin and uh the ASA couldn't handle it I ended up printing the Dual duct in petg it didn't need to be rigid because it doesn't really Define the whole structure of everything but when I went to mount the fans on it I I couldn't even screw them in because I guess the way it was designed there's no way I'm going to get a a hex driver on the other side of this fan to screw it in I guess you could use nuts with it and just screw from the other side but kind of defeats the purpose of it being designed for heat inserts but luckily I'd taken my own advice and printed out a bunch of versions and I still had two of these single ducks that were separated and these mounted just fine again that's why you should print multiple versions so that you don't have to stop your whole upgrade process just to wait on another print this is especially important if you only have one printer and you're in the middle of modifying that printer and a part breaks or a part doesn't work and then you have to put the printer back together and then print the part out and yeah just don't do that [Music] after getting the a sensor mounted there are only two things left to do and that was the hotend fan and the skirt my previous setup used this noctua 4x20 fan I basically chose this because I wanted my printer to be as quiet as it could be unfortunately as you probably know knock to a Fan's run at 12 Vols 24 volts which is what my printer ran off of so I had to add this bulky DC Buck converter on top of the print head which was both ugly and just unnecessary so I decided to ditch this luckily I had saved my old Viper stock fan and it turned out that this was just as quiet as the knock to without having to add this other junk it was also Slimmer and weighed less I also decided to ditch the fangu um I didn't think it was that useful also it collected you know pla strings and dust and made some of you quite [Music] uncomfortable after mounting the skirt I made the last minute decision to add some neopixels to the print head I had some on hand so I decided to solder them together put them in the enclosure and mount it to the print head [Music] [Music] [Music] [Music] after putting everything together this was the final product [Music] [Music] before mounting it to the printer I wanted to do a tiny bit of cable management you could use those cable Towers I talked about since I have the ebb 42 on my print head the wires don't have to go very far so I just used one or two zip ties to tidy things up now before mounting the print head there's one last thing to do and that is to basically level the fan ducks the ducks are designed to blow down just under your nozzle so you want them to be at the same level for one but also at the right height so one you're not blowing on the heater block or you're not down past the nozzle and you know hitting your part or the bed there's a part that you can print out you can either print it beforehand or print it on the bed and then just let it cool and um move the print head down and do it that way I chose to do it before I put the print head on I just thought that was an easier method you could also just wing it I mean maybe it's not that important after mounting the print head to the printer I turned it all on and prayed that the Magic Smoke wouldn't come out today yay no no fires I decided to do a pre-flight check and basically check that all the electronics were still working and that nothing was going to break I heated up the hot end a little I checked the hot and fan the part cooling fans and the be touch then I configure the neopixels in one of my last videos where I replaced all the electronics in my printer I actually had to Define an LED already so I thought it'd be really simple but it turns out that the neopixels actually need a fourth color defined which is white so they're rgbw until I figured this out basically the neopixels weren't being addressed correctly and they would produce either different colors or just the wrong colors outright but after getting that working and knowing that the neopixels weren't broken or nothing was shorted or anything I loaded up some filament and homed the [Applause] printer but before we start printing there's still a couple things we need to do the first is basically to recalibrate the printer the first thing was to redefine the probe offset from the nozzle this basically tells the printer how far the probe is away from the nozzle on my print bed there are two holes so I positioned the probe so that it would fall through one of the holes and then I wrote down the position it was at and then I moved the printer so that the nozzle was in the hole and I wrote down that X and Y position subtracting these positions from each other gave me the probe offset it's important to get this fairly accurate or else your nozzle isn't going to know the exact height that it's over the printer so the ACT ual Z height it could be the exact same but it could also be more than likely it will be higher or lower this could lead to some first layer adhesion issues it's really not that hard to get pretty accurate so just take a minute or two and do it right the first time with respect to how high the AL should be honestly I never do this the way they recommend I just kind of eyeball it as long as the a sensor senses the print bed before my nozzle senses the print bed I'm pretty happy after getting that sorted out I did a rough Z offset calibration just using the normal paper method I like to use this to get a good Ballpark and then I like to actually observe the first layer being laid down and do a live adjustment of that Z offet to get it just right I then wash my build plate off with warm soapy water just to get rid of all the sugars and any debris left on the plate after getting it back on I heated the build plate to 60° C and calibrated the first bed mesh next I found my new input shaper parameters at least just for the x-axis if you're interested and learning more about input shaper then check out my last video on it the final calibration for the printer was just a pit tune since we've changed the environment around our hotend and how it cools and heats up we need to repit tune it now that the printer was calibrated I decided to go ahead and retune the filament I basically did the temperature Towers flow calibration pressure Advance retraction all the good stuff I ended up doing two separate profiles one for 200 C and one for 230 C the speeds for those profiles were limited by by the max volumetric flow so at 230 C it was about 3132 cub mm/s and then at 200 CS it was about 20 Cub mm/s I did this so that I could compare cooling at basically different temperatures and flow rates the first thing I decided to do was to print out a Beni sort of um it's actually a voronoi Beni I basically printed this out to stress test the cooling and retraction I also printed out one without part Cooling and amazing am L it actually finished I did the exact same thing with two normal Benes one with part Cooling and one without part Cooling and really the only thing you can see immediately is that the funnel doesn't look right but upon closer inspection you start to see a lot of things like the gapping on top you can see the concavity of the hole you can kind of see the the surface finish just doesn't really look that great but amazingly a lot of the larger features don't look that bad at all without part cooling so clearly different featur feat of these prints require different amounts of part cooling the larger features need less Cooling and the smaller features need more part cooling so we'd like to be able to tune our printer so that it cools less for when it needs less and cools more when it needs more something that you can actually see on the part cooled Beni is that one side of it looks a lot better than the other side and this is because of how I had it oriented on the printer basically part cooling tends to be directional most printers like my prusa mini they have part Cooling only coming from one side whereas the hero me actually has part cooling coming from two sides but while it does cover the front and sides a lot better the back still doesn't get the same amount of cooling as the front and [Music] sides give [Music] ideally we can tune our part cooling so that it blasts Bridges and overhangs with like all the air we can get while it runs cooler for the larger parts so first I wanted to start by printing a bunch of parts at just 100% fan speed to kind of show off what the homi is capable of earlier I showed the do decahedron model it printed this out really really well um really no issues with it at all I also printed out this big lattice structure that basically acts as um a bunch of overhang tests set one and besides a lot of stringing because I was at 230 CI for this um it printed really well the next thing I wanted to do was check out how the heroi did with some extreme bridging I grabbed this really unique Bridge off of printables that has this cool overhang feature on top so I imported it into my slicer and I stretched it out out which made the bridges longer and the overhangs even more steep check out how the heroi handled that [Music] the bridging was pretty amazing at 200 mm or longer distances without much sagging on that first layer that's deposited but I still wasn't satisfied I needed to defeat the final boss of part cooling I considered that to be the pin support model challenge if you've not seen this it's basically a model generated that has one long pin support and then you print out an object on top of it the first one you can print is a cone that is facing upwards and the other is a sphere which is the harder model to print I decided to start with the cone the easier of the two and it printed out perfectly first [Music] try then I generated the sphere g code uploaded it and saw how it [Music] [Music] went it printed out perfectly again on the first try and this is the hard of the models I mean these first few layers after the pin support are literally just horizontal 90° [Music] overhangs I don't know about you but I was seriously impressed so the homi cooling system is clearly a very capable cooling solution but Andy says that you don't need to run it at 100% speed he says something like 30 to 40% is all you really to run it at and then maybe up to 60 or 70% for overhangs and bridges so I wanted to test that out and see if that's true for both the 200 Celsius and the 230 Celsius profile I printed out these overhang tests from 10% fan speed up to 100% fan speed and increments of 10 so let's start out by listening to how loud the part cooling fans at each fan speed [Applause] [Applause] now let's check out the results of the overhang [Music] tests clearly at slower fan speeds there is a difference in how well the overhangs print out but at the higher speeds there are diminishing returns for the 200 Celsius profile I think that 30 to 40% fan speed worked great for overhangs from 40° and under but for the more extreme overhangs from like 50° and above I would say that they didn't really improve that much past a 50% fan speed on the other hand the 230 Celsius profile was a lot more problematic it showed a clear need for much higher fan speeds on basically all of the overhang levels so I'd say Andy was right on the money for for average printing conditions so 200 Celsius for pla not printing that fast but when you get up to higher speeds you definitely need that part cooling cranked up I also ran a few more of those cool Bridges at 70% 40% and 20% fan speeds to check out how the bridging would do at different [Music] speeds I'd say that the 70% and 40% looked pretty pretty similar to the 100% fan speed one but the 20% fan speed is where it starts to fall apart now I really think that these Bridges could have come out better if I would have slowed the entire print down basically the first layer of bridging turned out really well but then when you go really fast for those next layers the plastic that you lay down is hotter and it either goes between the gaps of the first layer or it causes the first layer to Sag because it kind of Heats it up again so the hero is clearly top of its class for part cooling but as mentioned it isn't really for everyone so maybe when you saw the pen support test you said wow that's really cool I want to do that or maybe you said why doesn't this idiot just use supports and I think both of these are honestly Fair points of view the heroi partk cooling can be a bit overkilled depending on how you print if you mostly do higher temperature Plastics and don't really use partk cooling then yeah you won't need it if you mostly print pla but at really low speeds and low temperatures then again you probably don't have a big need for part cooling but if you want to print at faster speeds or you want to do some extreme Bridges or overhangs then I think you do need something like the her me partk cooling system or your partk cooling just won't be able to keep up with the demand now while I think the homi system is awesome there are some things that I don't like about it the first one is just how bulky the print head is not only does it look pretty clunky and large and not very agile um I would would say it's not very aesthetically pleasing and if that matters to you then you know sorry I personally like the approach that the voron designers took and how they designed their stealth burner I think that is a beautiful print head the other issue with the bulk of the print head is that it puts more strain on your printer now while all of the plastic parts don't weigh that much compared to your direct drive extruder the thing is that it sticks very far out from the Gantry so the more that your print head sticks out from the Gantry the more torque that is going to be applied than if you had all the mass closer to the Gantry and again that's what the voron designers did is they made it tall rather than bulky and having it tall puts all the force as close to that rotation Point as you can rather than having it further out maybe the torque isn't large enough to really matter but torque typically changes the lifespan of our mechanical Parts makes them louder in my slow motion Clips I actually found that my print head bounces up and down as it goes I'm not sure if this would be remedied by kind of reducing that torque or if I just need a more rigid motion system but that torque I was referring to was only in the YZ plane but there's also torque in the XY and XZ plane the XY torque occurs when the print head accelerates in the x-axis especially on bed Slingers basically imagine that your print head is mounted here but it either hangs too low or hangs too high like in the case of the voron one when it accelerates if this is where it's mounted and there's some Mass up here this mass is kind of going to get left behind so there will be a torque applied there and that's torque in the XZ plane which I think doesn't really matter as much in the case of the ham system because it is all pretty well centered around the the place where it attaches the one I think that is more concerning is the torque in the XY plane and this is again when the print head kind of accelerates on the x-axis basically think about like the stuff further out in front kind of getting left behind in that same way so if if this hand is the Gantry and this hand is the the tip of the print head or the the part most furthest out then as the Gantry accelerates you're going to get kind of this like back and forth motion there where the print head will kind of shake left to right and again there will be more torque in this plane when the print head is further out from the Gantry you can also counteract this by not having all the mass on one side of the Gantry but having some on the other side as well the prusa mini kind of does this by having its part cooling fan on the opposite side of the hot end so yeah that's one thing I don't like is how bulky it is the other thing I don't really like is the accessibility of it anyone can print the hom me system out but if you don't have a soldering iron then you're basically not able to have the hom me system I think it could also be designed so that you can use nuts instead if you wanted to I think the prusa printers use this approach so that people don't need a soldering iron to put the printers together but to be fair that is a lot of work when you consider that I got my soldering iron for the price of three spools of PLA and if you're a hobbyist it is a good investment so maybe that's not a big deal the final issue again it's a small issue but it's something that Andy says about the part cooling system that I think is inaccurate he claims that he designed the ducts in a way that it produces laminer flow which is more efficient for part cooling I would say it's pretty well known as in you can do a quick Google search and it pops up with a clear answer that turbulent flow is more efficient in part Cooling in laminer flow in laminer flow basically there are sheets of fluid or air which is considered fluid um there are sheets of molecules that move with the same velocity and if you have a surface that you want to cool um there's going to be a layer of molecules there aren molecules coming in and out of that layer um and the way that heat is transferred is when molecules bounce off of the of a surface basically so if there's a layer there and molecules aren't bouncing off then and um basically the cooling isn't as efficient Maybe by lamin or flow he's referring to the flow inside of the ducts which would make air get to the um the part you're trying to cool more efficiently I would say that's fair to say but I feel like at this small of a scale it really doesn't matter if your flow is laminate or turbulent I don't think it'll make that big of a difference I personally think that saying lamin or flow is just kind of a a buzz thing to impress people but maybe I'm wrong I have heard him mention in an interview that he has someone I think he set up in New York that he's kind of partnered with that runs airf flow simulations on the parts um I don't know if he's published this anywhere or made a video on it but I would definitely love to see those results um just cuz I think they'd be cool but um yeah just disclaimer I I still really love Andy's work and support him all the way um I just think that that lamin or floit is a bit inaccurate yeah I think that's fair in the future I'd love to learn to run my own fluid simulations but I'm not at a point where I can do that yet I was thinking about getting some incense so that I could burn and have the smoke kind of you could uh visualize the air flow around the print head but I didn't get around to it so I ended up doing the water a bow test that everyone seems to do and at first I thought it was silly but after I did it I got some really cool shots so let's take a look at how the water looks at different fan speeds the [Music] [Music] these results basically show that yes the Ducks are pointing the air right where we want them we can also see at really high speeds that the cooling really is power powerful so if you're stuck with your stock part cooling then you probably do need to run your fan at 100% just to get your parts cooled but the hero Me by having two large powerful fans and by being designed so well you can really run those fans at a lower speed giving you quieter Printing and just really really quality part cooling so how should we actually calibrate our part cooling so I talked about why part cooling might be more complicated and nuanced than you thought I talked about how to get the best part cooling currently available and now I want to quickly talk about how to tune your part cooling to get the best results and by best results I really mean the best print quality balanced with not overcooling your parts so that you get better mechanical properties out of them as far as I know there's not really a standardized way to do this yet the way I chose to go about it was by doing my normal filament tuning where I do temperature Tower um flow calibration pressure Advance retraction towers and then um I like Max volumetric flow rate I then printed out those overhang tests at all the the different fan speeds and increments of 10 I tried doing like a fan cooling tower because I know slicers like Cura have a plugin that lets you automatically generate a tower that does the different fan speeds as you go I tried doing this with manual G-Code inside of uh Orca slicer the slicer I use but the fan speed would always kick back up to 100 and I couldn't get it working so I did it this way you could definitely start at something like 50% and if you clearly need more cooling bump it up if you need less cooling bump it down and you're basically trying to find two fan speeds the fan speed you need for the most extreme overhangs and the fan speed you need just for the basic printing so like overhangs 40° and under again the logic behind this is that you can still print things but you're not overcooling the plastic so that it becomes more brittle you get worse layer adhesion all that kind of stuff but you are still cooling parts that um sections that are either very small and need that extra cooling or extreme overhangs or bridging for my 200 Celsius profile I found that 50% fan speed was good enough for all my bridging extreme overhang needs so I set the rest of the part to be cooled at 20% fan speed and I printed out a binci with those settings for my 230 Celsius profile I found that I needed 50% fan spe speed for my normal part so the the bigger pieces and then I needed 100% part cooling for um overhangs bridging and small sections I again printed out another Beni and this is what it looks like another thing you probably already know about the different temperatures of printing is that um it can change how shiny your part is I don't know if this is affected by how quickly it cools or if it's purely the temperature that you raise the plastic up to but again maybe I'll look into that in the future so yeah now we've talked about how to tune this video took a while to put together life has been pretty crazy the last few weeks so I hope you really enjoyed this or you got something out of it and learned something new if you want to help me improve these videos leave some feedback on something you think I did well or things that you think I should do differently I'd love to hear from you if you made it this far thank you so much for your support it means the world to me and I will see you in the next video bye oh

Channel: Spencer's Desk

Views: 25,402

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Id: rI-ISZsXBMo

Length: 47min 27sec (2847 seconds)

Published: Tue May 28 2024