GAME OVER For Hotend/Extruder Design? - The Biqu H2 Direct Drive Hemera Alternative

you guys know me right i'm uh overly critical i kind of consider that to be my job you know when you're on amazon and you're judging a product you never read the one star reviews those guys are just dripping with some unreasonable emotions and they're not going to say anything that's useful but those two star reviews where somebody hated the product enough to leave only two stars but they clearly were emotionally balanced enough to be like hey it's not one star it's better than that right like i'm basically trying to make a channel that's a two-star review of everything i'm trying to give you all of the negative aspects of a product so that you can really know what it's going to be because if if i give you all the negatives then you know that everything else is positive and you know i'm just trying to make the tech better i'm trying to make the world a better place even if it's just by improving the tech and 3d printers so uh i got this bq h2 extruder in the mail i ordered two of these after seeing my friend's review video over on the 3d print generals youtube channel and i opened the box last night and started to really analyze this thing doing my two-star review on it and i can't find anything to say you guys i can't find anything negative to critique about this extruder it's kind of heavy that's it but it's lighter than a normal full-sized nema 17 stepper motor would be so somehow we could bring the weight down and that's about the only thing i can think of it's amazing uh last night when i was looking at this first you know first impressions i was thinking this is game over there's never going to be a better hot end extruder combination than this um it looks a little bit it looks a lot like the hemera but it's better in every way than the hemera so and it's not even a clone there's nothing cloned about this hot end sure it's extremely closely derivative of western products but everything has been improved upon which is the spirit of open source that we embody with um what am i going to call it the um consumer level 3d printers that we all play with so they've nailed it this chinese company bq has absolutely absolutely nailed it i don't think i've ever been so impressed with a 3d printer component as i am with this so let's take it apart and i'll show you how every single piece of this is just incredible [Music] speaking of weight this whole thing the whole assembly weighs 19.7 grams a normal sized stepper motor for 3d printers here this is like a full-size stepper motor weighs 28.2 grams you start to get a little bit smaller than that here uh this is what you typically would see like when you have dual z lead screws and you don't need as much power 21.7 grams okay this getting smaller still just depending on how much torque whichever application it is is needed and that one pretty much matches the entire weight of this whole hot end so what we would typically expect to see as a pancake stepper motor for lightweight applications up until now 12.8 grams so that is significantly lighter than the whole apparatus here but let's take off just this little mini stepper motor and see how much it weighs yeah so this is basically a pancake stepper motor itself except that in these dimensions it's clearly quite a bit smaller and it weighs 9.1 grams so 10 grams lighter now i'd love to see them use titanium or aluminum or something even lighter weight maybe drill holes in this any material that's not needed you know because stepper motors are quite heavy but part of that you can't do anything about it because uh magnets are heavy you know that's just the way it goes and when you're preferencing magnetic qualities of metal you absolutely cannot be finicky and picky about the weight of the thing so that's how that goes we do need the strength the torque so it's a it's a trade-off lighter weight means less torque anyway that is incredibly impressive as far as the size and the weight to talk about the rest of these components let's get a closer look this lens is crazy you can see the teeth here are in focus and the hob gear is out of focus so it's got a very shallow depth of focus depth of field and the teeth here speaking of those are steel look at the magnet sticks to them yeah so all of the gears in the assembly this one this one and this one are all made by machining steel and not only that the um you can see the machining lines you see those shining off of there so there's concentric machine lines and if i scratch it you can hear what's going on there that means that this was machined it was lathe this is not metal injection molding you guys this is a high quality machined teeth which means that you're going to get much better engagement with these teeth in the other teeth you're going to get better what's the term meshing synchronizing of the gears there which is just phenomenal what a great attention to detail the um the gears smell kind of like bicycle lubricant so i don't know what they've actually used to lubricate it but it's a very light oil so it's not too messy and if we look at this hob gear it is not a knock off of the bond tech that is going to be a very similar same idea but you know what that is not bontec's unique idea bontech just had a great implementation of dual hog gear timeout i was just editing this video and decided to double check myself and see if i was right about this not being a cloned uh hob gear assembly that the dual driven hob gears so here on the bondtech website we can see these smaller uh dual driven gears these are the ones that i'm used to seeing i had not ever seen the larger size there in the background we're seeing that larger size and so it does appear that the uh the dual hob gears on this um bq are cloned from the bond tech design which is that's bad cloning is bad form but uh there's a problem with that as i see it and that is the fact that once you clue in on dual hob gears as the thing to do um and you start simplifying and and value engineering it this is the answer that everybody's going to come to there's uh i think the the leap here you know the the the intellectual property is just the idea of driving it with two gears driving filament through a two with two hob gears so in this instance it's a bit more of a gray area than other clones so i don't like clones they are bad for the hobby they are bad you guys but uh you know whatever it is what it is here in this assembly we can see the other side uh the other corresponding hob gear the pear the twin and you would expect this arm right here to be made out of plastic wouldn't you but it's metal everything on this hot end is metal it's amazing and all of the pivot points are bearings the only bushing on the whole apparatus is the pivot point for the lever arm all of the metal that doesn't need to be like durable i'm talking about the steel gears here all of this is made out of aluminum which has been anodized black so if i give this a scratch here we'll see the the shiny aluminum underneath this hot end here is kind of a unique shape and it's also an aluminum block with your typical brass nozzle a little bit of a large hole there i guess they're expecting you to use a cartridge style thermistor this looks to be a standard nozzle throat size so i should be able to get the slice engineering throat the fancy one with the bonded copper and stainless steel and i should be able to throw that onto this assembly which would be really cool there is one potential achilles heel of this hot end and that is the fact that this little motor doesn't have a lot of torque and so it's going to get geared down quite a bit i think it might be a 27 to 1 here i'll put the correct ratio on the screen so that gear ratio is going to mean that this motor is going to be spinning really quickly and we all know that stepper motors do not do well with high rpms so there's a potential for problems with that i don't see this as a high flow solution but it's pretty fantastic for the way that most of us use 3d printers okay i think i found one a legitimate gripe the gears despite being machined steel are not perfect and as i spin this i get to sort of tight moments there's a it's spinning pretty freely right through there and then ah you know it's spinning okay right now so it comes and it goes and granted i don't have this side of the um of the shaft of the axle secured at the moment but when i put the whole thing together and try to drive it by the large gear here i still have problems so even with the axles fully seated the gears can have tight spots anyway to try to alleviate this problem i'm going to use this gear butter a friend of the channel michael hathaway he's actually the executive producer of this video and he's he sells this stuff so yeah look him up i think it'll work well in this application which is metal to metal he also sells this tink seal stuff which is really cool it's got these nano particles and it may be graphite i don't know he won't tell me what's in there but uh this is meant to be a plastic to metal um lubricant because the grease eventually like dries away and it leaves just the nano particles just the like graphite or whatever it is the phenomenal high-tech stuff and so you have a micro lubricant that's like a dry lubricant after the the grease kind of dries away and it doesn't damage your plastic so yeah pretty high speed stuff there but uh that's the wrong stuff for the application we're going to use the gear butter actually that gear butter has made a huge difference i was not expecting that so wow props michael now it might just be that the lubricant that came on this was really poor or pretty much non-existent so any lubricant might have helped but dang that's so much better all right i've got the thing back together but i can't drive it by spinning this wheel it's all it's all seized up and i could before i took it apart just now so what i did is i rotated the um plug here it was at the bottom and i rotated it up to the top so i think i need to align the stepper motor in such a way that it's um sort of pushed away from the other gears i think it's too tight too close to the gears and it's binding everything up well i'm actually really struggling to get this thing put back together so currently i just have these two gears going into the the housing here and uh it's still pretty difficult to turn there are moments like right there where it's really tight quite tight and then it's loose across there and then it's real tight again so they did a good job these are machined gears which typically is what you want for accuracy because metal injection molded mim gears are not as precise but ah this is bad you guys this is this much friction in the gear train is going to mean that this little tiny stepper motor is not going to be up to the task it's not going to be able to push it's going to be using up all of its torque just to get the gear train to turn over let alone you know torque actually being used to push the filament through the hot end okay well after about an hour worth of tinkering i finally got it to this position here and what i had to do in order to get here was quite involved so let me tell you guys first i've got this little condiment container and i filled it up with paint thinner and i was able to sort of shake it around with the gears inside of it to clean all of the you know shmoo all the dirt and debris off the off the gears because you know they played that nasty old chinese trick on me where they send you a product without actually cleaning the gears after cutting them and grinding them so you have all that grinding dust left on the gears they're not cleaned well enough and that didn't solve the problem so i had to dig into it even more deeply what i did is i started spinning it by hand just like this until i can feel like there's a tight moment right there and i used the sharpie to sort of blacken the gear and then i would take a sharp pointed needle file and score right there at the tight spot so now i can take it apart and i can see that scored line and what i can do is opposite the scored line over here on the shaft i can take the needle file and sort of grind down the shaft and about an hour of this constant measurement re-blackening mark and mark where it's tightest and don't forget to do the other side of the shaft that's how i was able to size that shaft down and actually what i'm doing is i'm centering the shaft because the gear is eccentric there's a slight bit of wobble to it the passive or driven side of the dual feeding hob gear mechanism with the arm is a little bit problematic because that axle is a press fit in there and without drilling a hole here and pressing back from the top i have no way to get it out to inspect it it does feel like there's a bearing inside of there and that's about the right height for one of those needle bearings that we've seen previously on the like bond tech knockoff versions but those gears have not been beveled really well i guess there is a slight bevel to them so hopefully we're not going to get this condition where the gears grind into the aluminum carrier only time will tell well that was a lot of work but it was absolutely worth it that is smooth as butter the whole way through now there's no tight spot whatsoever so that is ready to be installed onto the printer so i opened up the box here to get the fan that goes on the end and yeah there was a lot of other stuff included a really high quality heater cartridge and the thermistor cartridge that silicone boot is able to clip around and hold on to that hot end better than any of the other silicone boots i've ever used also included in the box are some allen keys this um fan cover that i'm not going to use because i'm trying to save weight and a rubber ducky don't know what that's for want to see something in front of you guys this other one is perfectly smooth through all of its travel straight out of the box so all that work that i had to do on this one not necessary on the other one so they just have quality control consistency issues there at the factory actually you guys this is a slightly different design so what i might have here is two different iterations and this might be the old iteration and this newer one is when they've got everything figured out you see on this one if i undo these two bolts instead of just this front half with the lever arm popping off it actually allows me to spin the stepper motor and orient the plug upward so those bolts go all the way through whereas on this one those bolts just go this far and then there's a separate set of bolts connecting the stepper motor to the um the actual hot end slash extruder assembly well this hotend is going to go on what's left of my two trees sapphire printer i have heavily modified this thing and unfortunately you can't even buy this model this was the first one they put out and it was the superior model because it has these stepper motors for the x and y axis underneath the floor which isolates them from a heated chamber i'm going to build this thing into a heated chamber and these rods come all the way up here and they control the belt so everything on this printer is made out of metal except for the belts that's it and this entire hot end extruder assembly also made out of metal no plastic on this thing except for the fan here and the uh the silicone sock so this is going to mount right under there eventually i have to cut the tang off of the side of this and i have to do a bunch of work to the printer in order to get it switched up but this printer i do have a massive upgrade this is going to be the best printer that i've ever made here when i can get to this project unfortunately i have to put this on the back burner there's other priorities i don't have the five days to spend on this printer that it's probably going to take me to get it where i want it but that doesn't mean we can't test this so we're going to plug this into the control board there and just see how fast we can push filament through it all right this whole hotend is set up in firmware now the steps per millimeter have been changed so that it will feed through exactly 100 millimeters when i tell it to and the thermistor values as well have changed so that um that is accurately reading 220 degrees for the hotend temperature for extruding some pla here this black mark that you can see on the filament is 100 millimeters so right there the near edge the close edge to the to the extruder and what we're going to do is go right to the top 60 millimeters per second see if this thing can handle it without skipping steps nope that seems to have missed a lot of steps that's nowhere near correct well that's not surprising this isn't something i've paid extra close attention to but i know that i skip many of my other extruders at that fast of a feed rate i don't even think that most of my extruders can handle 30 millimeters per second so let's try 15 millimeters per second and see if this works got a new black mark there yeah i could definitely actually visually see it skipping and not able to keep up with feeding through all right g 0 e 100 f 600 which means a feed rate of 10 millimeters per second there's my black mark let's see how it does nope it can't handle 10 millimeters per second let's try the feed rate f400 not quite it skipped a step or two didn't quite make it all right f 345 which equates to a um what is it 5.75 millimeters per second feed rate so let's see if it does this one yeah that one worked perfectly all right let's talk about it i did the math i'll flash that on screen basically this thing can handle 175 millimeters per second print speed when you're printing with a 0.4 millimeter nozzle at 0.2 millimeter layer heights and that is much faster than most of us ever print i have my fast delta printers and they can handle speeds up to like 300 millimeters per second but it's all about the acceleration and you do have flow characteristics uh about the the you know the filament coming out of the nozzle things don't cool right they don't lay down right there is i think that the sort of limiting factor on fdm 3d printing is the flow of the filament out of the nozzle so i'm finding personal experience at the moment and this isn't like my life i don't spend my life trying to tune printers and get them to you know squeeze out filament as fast as possible it's kind of a thing that i dabble in so don't take this as gospel but at the moment i'm finding that 100 millimeters per second is kind of the upper limit on uh print speed for for that balance of quality with print speed and after that it's really all about acceleration and jerk settings which is you know completely dependent on the inertial mass of your printer so all of that is to say that there's kind of a speed limit kind of a speed limit on fdm 3d printing of around 100 millimeters per second in my experience so with this thing able to go 175 millimeters per second with a normal nozzle ah it's well and truly an option there's it's not going to be the limiting factor the small stepper motor is everything you need it to be and in fact that's a nice margin of safety margin of error there as the engineers would normally do you you take your your failure and you divide that by two and that's the rating so if something fails at a thousand pounds you rate it for 500 pounds of load so that's almost double the 100 millimeters per second so i think we're good now there's all kinds of other considerations in print speed first of all you have how sticky is your filament i'm thinking petg is a bit more sticky than pla so maybe there's more resistance i don't know the viscosity of it i don't know what the flow behavior of it uh you know at the higher speeds or anything like that so there's so many things to test how how fast can you squeeze the different filaments through this what happens if you put a bigger nozzle in there well surprisingly a larger orifice increases the pressure this is bernoulli's principle so it's going to create more resistance to have a larger nozzle you would think that it would be the opposite you got a bigger hole to squeeze stuff through but it it kind of comes out the other way so you're likely to get more back pressure uh on the um the larger orifice like a point eight millimeter nozzle something like that which could cause the stepper to skip so if you go with a point six millimeter nozzle because of the the way that the because of the way that the map all works out the 0.6 millimeter nozzle might actually cause this stepper motor to skip at i don't know uh 80 millimeters per second so maybe half as as quick as it can go right now that's a guess i'm just guessing they're pulling numbers out of my butt i didn't crunch those numbers so yeah there's all kinds of considerations but the bottom line is this all metal super compact hot end works it just works it gets it works at the right speeds and it's lightweight and i love it i absolutely love it this is totally the future and the reason i love this i think i already mentioned it's because it's all metal so i can stick it on that printer and put that printer in a heated enclosure and i don't have to worry about the thing melting or things going wrong at high heat but you pay a price for that metal you do you pay a price for that metal so wouldn't it be nice to have a plastic version of this well it's amazing i think we're living in this golden moment here we're finally seeing some more innovation in hot ends and um thank you to the lightspeed he's a viewer of this channel and in one of my live broadcasts he pointed out that printed solid is selling a hot end kind of similar to this only instead of the involute gears it has a planetary gear set in it and i guess planetary gears have enveloped gears too but anyway different slightly different kind of geared mechanism and it's all plastic which means it's going to be a whole lot lighter weight unfortunately printed solid is sold out of that hot end but i found it on aliexpress so i've got some of those on order as well and if they do everything that this one does but they're half the weight i'm going to be sticking those direct drive extruder hot end assemblies onto my delta printers because we all know that you get better print results from direct drive but again there's a huge caveat there um this whole what does marlin call it um well it's it's um linear advanced i think that's what marlin calls it linear advanced and in reprap firmware it's called pressure advance and rap rap firmware uh those are the guys duet they're the guys who originally developed that functionality and it's awesome it basically predicts the um the spool up the the sort of like rubber band or spring effect that you get by trying to feed filament through a bowden tube so you can compensate for the um the thing that a bowdoin tube fails at that's that springiness in the system you can compensate for that with software but it's always best to solve the problem at the root at the base level which means direct drive extruders so i really do think that this is just going to guarantee really high quality prints without so much work in firmware and all of that that's not to say that bowden tubes are dead or anything like that but it's just it's really awesome to see smaller lighter weight yet fully capable direct drive assemblies uh coming onto the market i'm really excited for this um but we saw you know all all of my initial excitement tempered a little bit because of those gears kind of you know that i had to rework and um you know there is a top speed that you can print at but no it really does fulfill its promise this is awesome i cannot wait to start to see this component on 3d printers as we buy them so we don't have to it's not just you know the expert level uh you know hacker who really wants to modify the 3d printers that can start to use this functionality i would love to see this coming stock on printers all right that's where we're going to leave it a big thank you to my patreon supporters that's these guys uh without them i would not have a channel you go you guys would not be watching this video that's the absolute truth so these guys are awesome and they keep this channel going thank you so much that'll do it for this one thanks for watching see you next time

Channel: Design Prototype Test

Views: 72,717

Rating: 4.5985951 out of 5

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Id: 7IJaD15UQU0

Length: 27min 15sec (1635 seconds)

Published: Sun Feb 14 2021