Hello, 3D Printing Friends! Today on the BV3D Channel, we'll take a look at the BIQU H2
Compact Direct Drive Extruder! Stick around and we'll get into it right after this.
I'm Bryan, and you... are watching BV3D!
Hi, welcome back! Hey, if you're new here and you're wanting to learn about 3D Printing,
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so you don't miss anything! Okay, so today we're going to take a look at the BIQU H2
extruder. As many people know, there are two general kinds of extrusion systems on 3D
printers that use filament. Some employ a Bowden drive extruder system. This is a system in which
the extruder motor--the motor which pushes the filament--is somewhat removed from the hot end.
The motor is generally mounted to the X-axis arm, and pushes filament through a Teflon tube to get
it into the nozzle. It doesn't move with the hot end, and so the tube and the filament within it
have to flex to accommodate the hot end's motion. As a result of the distance between the extruder
motor and the hot end, and the amount of play between the filament and the tube, some kinds of
filament--particularly flexible filament (yes, I'm looking at you, TPU)--can be difficult to print.
Other printers use a Direct Drive system. This is a system in which the extruder motor is mounted
directly above the hot end, and pushes filament straight down into the nozzle.
The path from the extruder motor to the hot end is short. It's just a straight shot. Flexible
filaments are easier to print because they're being pushed directly down into the nozzle without
the opportunity to bunch up in a long tube. It's possible to convert a Bowden drive 3D printer to
a direct drive, but most solutions simply move the existing extruder motor from the side of the
X-axis arm to the X carriage, basically shortening the Teflon tube to the minimum length necessary,
and often becoming quite tall in the process. Apart from the weight of the additional 3D printed
or metal parts needed to mount the extruder motor, this doesn't add a lot of mass to the X-axis
overall. But it does move the mass of the stepper motor and the mounting components
to the X-carriage. In a Bowden setup, the printer doesn't have to sling the extruder motor's mass
back and forth while it prints. But in a direct drive setup, it does.
In an effort to provide a direct drive extrusion system with the smallest possible size and mass,
BIQU has produced the H2. In design, it appears very similar to the E3D Hemera,
and before you yell CLONE! I'd like to point out that superficially they BOTH remind me of
the direct drive extruder on my Monoprice Maker Select Plus, with the addition of a
geared filament drive system to increase their filament pushing power. Like other direct drive
modifications for the Ender-3 series, this one is a DIY affair. So let's see what comes in the kit!
You get the H2 extruder, gearbox, stepper motor, and hot end assembly; you get a heater cartridge;
a thermistor; a 30 millimeter fan; a grille for the 30 millimeter fan; a cable for the stepper
motor; Allen keys; screws; an info sheet; and the traditional BIQU/BigTreeTech rubber ducky.
All the cables included in the kit are about one meter in length. That's a problem, and I'll
explain why in a little bit. Now, because this can be mounted on many different makes and models
of printers, and in many different ways, there are no mounting plates included. Fortunately,
printable mounting plates can be downloaded from BIQU's website for different printers.
For example, there are printable mounts available for the Ender-3 and 3 Pro, and for the Ender-3
V2. There are also printable fan mounts, so you can continue to use the stock parts cooling fan.
Now, I found the stock fan to be inadequate when used with the H2, so I tried a couple
of other fan mounts that I found on Thingiverse. One for a 4020 blower, and one for a 5015 blower.
The one for the 4020 blower used a ring type of duct, and the one for the 5015
blower used a duct similar to the one on the Prusa MK3. In testing, I found the 5015 blower
with the MK3-style duct to be the best of the three, so that's what I've got mounted here.
And you know, I realized after having had this 5015 blower on the printer for several
weeks that the mount was blocking airflow across part of the heatsink that cools the heat break.
Now I haven't had a problem with heat creep or filament jams, so apparently I have enough
airflow to keep this cool. But I may redesign that mount to allow more airflow across the heat sink.
If you don't mind messy wiring, you can zip tie the H2's wires for the heater, thermistor, fan,
and stepper motor to the outside of the existing cable sleeves. But I wanted this to look nice,
so I completely removed the wiring harnesses from the printer. I pulled the wires from the
sleeves and then I put them inside this reinforced textile sleeve instead. I like the look of it.
It's similar to that split loom cable cover stuff, so getting the wires inside is easy. It has enough
rigidity to keep itself from flopping over, but it also has enough flexibility to bend where it needs
to. I know other people have disassembled their H2 and rotated the stepper motor such that the
connector is on the top, but I like the cleaner appearance of having the connector on the bottom.
I've got all the wires neatly bundled and routed together and I think it looks pretty good. Besides
the necessity of printing a mount and a fan duct, and replacing the stock parts cooling blower with
one that has greater airflow, I also added a PTFE coupler, and a VERY short length of PTFE tubing to
the input side of the extruder. Otherwise, the filament is just going to go down into a large
threaded hole. Using the coupler and the tubing helps to guide the filament down into the hot end,
and this also allows you to do what's called a reverse Bowden setup, in which,
yes, you have a Bowden tube coming off the extruder, but it's simply a guide.
The filament gets pulled through it, not pushed. You may have seen other videos where I have the
spool holder mounted to the front left corner of the printer. That's where I like to put it,
because it's easy for me to get to, it's easy for me to see how much filament I have left,
it reduces the overall height of the printer, and it's not in the way of any of the wiring.
But that position doesn't work well for a direct drive extruder. Direct drives tend to work best
with the spool holder at the top of the printer. By using a reverse Bowden setup, the filament
input for the extruder is moved to wherever the open end of that tube is. So I could, if I wanted,
design a clip for the open end of the tubing, mount it right over here where the original
extruder motor was, and then I could keep the spool holder at the left front where I like
it. Now, I said this was a DIY kit, and frankly it was a little MORE DIY than I was expecting.
As I mentioned, a moment ago this can be mounted on many different makes and models of printers,
and in many different ways, and as a result, there really aren't any step-by-step installation
instructions. So you need to have a good idea of how a direct drive extruder should be connected
in order to be able to pull this off, and you need a good sense of how the X carriage on your
printer works, and where things can be attached to it. Now there WERE a couple of issues that I ran
into. For instance, the printable Ender-3 V2 mount makes use of a couple of threaded mounting holes
on the X carriage, but the Ender-3 V2 that I was mounting this on is a very early production model,
and its X carriage doesn't have the same hole pattern as later ones. In fact it only had ONE
of the two holes that were needed, and that hole wasn't threaded. Plus, it was too large a diameter
for an M3 bolt. So I needed to add the missing hole. I removed the X carriage from the printer
and marked where the second hole needed to be, and then drilled and tapped it for an M3 bolt.
For the hole that was already there, I'm just using an M3 nut around the back side of it.
Now, this issue is probably exceedingly rare, and really it's more of a Creality issue than a BIQU
one. Now I mentioned this X carriage issue on a previous video, and a viewer recently commented
that they had the same problem, and they brought it up to Creality support, and Creality is sending
him a new one with the correct hole pattern free of charge. Another issue that I had with
the printed mount is that it had exactly zero accommodations for securing the hot end wiring.
I didn't want to have the hot end cable bundle just kind of flopping around,
so I imported that mount's STL file into Tinkercad, and I made some modifications.
A couple of prototypes later, and I had a mounting solution that I liked, with places for zip ties
that keeps everything in place. Speaking of the wiring, the thermistor cable and
the heater cartridge cable and the fan and stuff motor wires are just too short
to reach the main board on the printer. So I ended up reusing the stock heater cartridge, and I made
extension cables for the thermistor, heat break fan, and stepper motor. There was a fair bit
of connector crimping involved, and I discovered that the more you crimp, the better you get at it.
And it should also be noted that installing the H2 with a printable adapter plate means
that the nozzle is going to be somewhere between 10 and 15 millimeters forward of
the bed when the Y-axis is homed. It's not a HUGE deal, but I did want to mention it.
So after installing the H2, you should perform a PID tuning on your printer's hot end.
The settings in your firmware are tuned for the stock hot end, and so you're very likely to see
issues with the printer not being able to keep the nozzle temperature locked in where you set it.
Speaking from experience, this can make it hard to get your print settings dialed in for the H2.
Yes, I made a rookie mistake when I first installed the H2, and I completely forgot
to run Marlin firmware's PID Auto Tune so that the printer would be able to accurately
control the nozzle temperature. I was having a hard time getting the stringing under control,
and I was noticing weird issues on the retraction test models. The temperature swings were close to
about 10˚ Celsius, and the little towers on the retraction tests had a very regular, ridged look
to them, because the filament's appearance varies with printing temperature. But once I ran the
PID Auto Tune, the printer was able to keep the nozzle locked in at my set printing temperature,
and I was able to get the retraction dialed in. So if you want to know how to do that, I've got
a video linked in the description to show you how to run Marlin's PID Auto Tune on the Ender-3 V2,
Now let's talk about print settings for a minute. I use Prusa slicer for darn near everything,
but these settings should translate over to your slicer of choice fairly easily.
Direct drive extruders don't need a lot of retraction, and so I'm using a retraction distance
of 0.6 millimeters, no Z hop, a retraction speed of 60 millimeters per second, and a deretraction
speed of 40 millimeters per second. I have it set to retract on layer changes, perform a wipe while
it's retracting, and it retracts seventy percent before it begins the wipe. With these settings,
stringing is really very minimal. Also, it may not actually need to perform that wipe,
so you can try your own variation on the settings. If you're looking for that wipe setting in Cura,
I think it's called "Coasting." Okay, so here are some of the things that I printed with the H2,
all with a 0.2 millimeter layer height. I have a variety of vases or "vozzes" depending on
your pronunciation. I usually say vase but for the rest of this video i'm going to try pronouncing it
vozz. It sounds fancy! So I printed most of these in PLA, and a couple in TPU. I also have a couple
of Calicat models, a standard XYZ calibration cube, a couple of tripod wall mount hangers
that I designed, and I have a retraction test, and Loubie's Aria dragon. I also have a Benchy,
so let's start there. This Benchy came out pretty good. If you look really really closely,
you can see a couple of little strings inside the wheelhouse, but there are no major issues,
and the overhangs look really good in the doorways and at the bottom of the bow. The
stringing test has a few little wisps, but that's about it. The columns came out nice and even.
The calibration cube came out great. There's no issues, and the top surface looks really smooth.
this little calicat is also good there's a little stringing between the body and
the tail but the 45 degree angle on the tail looks good sometimes that part likes to curl
a bit if you don't have good cooling but I put that 5015 blower on the h2
so I think it's doing pretty good this bigger calicat is one that I printed in polymaker's
polyterra orange pla it's got a matte finish which seems to highlight any imperfections in the print
so some of this stuff that looks like it might be z banding I don't think it is these seem
to be directly tied to features on the model itself like the whiskers the nose and the eyes
i've seen that sort of thing on benchy prints too on the layers where the deck gets printed
now I don't know specifically why that happens though if you have any thoughts or theories on
that let me know in the comments on this tripod wall hanger that I printed in the polyterra
the effect is less noticeable I printed a second one in a marble pla and it's hard
to see any issues at all I think the marble pla's glossy finish and the little dark flecks
really hide the layer lines and imperfections and I think arya turned out pretty good too
but now let's get to the bosses printed in spiral vos mode with what I consider
normal settings with the 0.2 millimeter layers at about 45 millimeter per second
this low poly faceted vos came out great it takes about an hour but it
comes out fine and this was with the stock inter 3v2 parts cooling blower
one of the things you should be able to do with a direct drive extruder that has a geared drive
system like the h2 is print faster without the extruder stepper motor skipping steps and you
can definitely do that with the h2 but if you want to go fast heat is your enemy and parts cooling is
your friend using the stock parts cooling blower and slicing it to print at 100 millimeters per
second the vase only takes 24 minutes to print but the layers don't have time to cool sufficiently
before the next layer goes on and so the heat builds up the plastic stays soft and then the
corners start to curl up on some of these little overhangs and you kind of get this sort of effect
once the diameter of the vas gets big enough that one layer has enough time to cool before
the nozzle comes back around for the next layer that effect goes away interestingly it stays away
as long as the overhangs are on the inside of the vas but once the overhangs start being on
the outside again the effect returns printing the exact same file but replacing the stock
parts cooling blower with the 5015 blower and the prusa style duct significantly reduced the
appearance of that effect and it kept the same 24 minute print time so I think fast printing is one
area where there are definitely a bunch of factors to take into account to get good results
there may be some models that just won't print well if you print them fast and others
may work just fine now I tried to print this other vas model in a nice flexible tpu filament
and the first time I tried I noticed the nozzle was kind of pulling the model along with it
so the layers weren't lining up quite right as it printed so I cut the print speed in half while it
was printing and it started to look good again so I stopped that print and re-sliced it to print at
a slower speed and I thought maybe it would finish and then i'd have a nice squishy vase
now this time I got a much better result but once it got to a certain height the vas was
just too floppy and it started to fail again so I cancelled that one too I think if I experiment
with speed and extrusion width I may be able to get a vas printed in tpu that actually finishes
now if I take this model and scale it up to fit the printer's build height
and I use the spiral boss mode settings that I use for that first gray faceted vase
prusa slicer says this will take a little over six hours to print and prusa's slicer is ridiculously
accurate with these estimates but if I set every single print speed setting to 100 millimeters
per second and then slice it bruce's slicer says it'll take about 2 hours and 20 minutes to print
now I know that due to acceleration settings and whatnot the printer isn't going to realize that
100 millimeter per second speed and that's the difference between actual print speed
and commanded speed i'm commanding the printer to move at 100 millimeters per second and it's
going to try but its actual speed will be less but it will print pretty darn fast and in fact
the actual print time for this vas was 2 hours 23 minutes and I figured that extra three minutes
was due to the nozzle in the bed getting up temperature so the h2 is definitely capable of
high speed printing I think you just have to find the right balance of settings model geometry and
filament so that's the bq h2 compact direct drive extruder it's a diy project that can give you some
pretty great results but with the included wires being too short for an ender 3 series printer
they're likely too short for a great many other printers too I think if bq doubled or tripled
the length of the wires you'd probably be able to install this on even a big printer with a
300 by 300 by 400 build volume without having to make a bunch of extension cables also the
stl files available from bq for the printable mounting brackets and the parts cooling ducts
may not be the greatest but you can search and find other ones like I did for the parts cooling
ducts or you can modify existing mounts or even design your own so as impressive as the h2 is
just be aware that installing it is not a project for the faint of heart you need to be comfortable
working with your printer's wiring and you need to be good at crimping connectors onto cables that
said if it aligns with your skill set it seems to be a worthwhile upgrade and again thanks to
bq for sending this to me to test out and there's a link to the h2 and bq site in the description
well 3d printing friends that's about all the time we have for this episode and now that we're at the
end let's go print something cool hey real quick before you go I wanted to say thanks for being one
of the super awesome people who sticks around all the way to the end and thanks for all the
likes comments and shares and an especially big thanks to those who directly support what I do
you're all wonderful for doing that and I really appreciate it if you liked this episode a thumbs
up would be great and if you'd like to help support the channel check the description
for ways you can do exactly that and hey if you haven't already subscribed please do it's
absolutely free and it's an excellent way to help keep me making these videos for you well
that's it for this one thanks again and i'll see you next time here on the bb 3d channel