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

Direct drive extruders make superior quality 3D prints, but you pay a major price for that quality. They are slow! By reducing the weight you can speed up the printing. This hotend and extruder combination (The Biqu H2) is the lightest such design out there which is also 100% metal construction. Therefore you can put it in an enclosure and it will stay dimensionally stable. So what's the catch? What's wrong with it?

[biqu]

Thank you very much for your great review. Regarding the gear stuck problem mentioned in the video, we have contacted our engineers to deal with it. Later, we will strengthen the quality inspection of parts to avoid this kind of problem. Your suggestion is of great significance to our future improvement. Once again express our sincere gratitude

[JOEDHIGGINS]

Because we are dealing with subsonic flow, the nozzle is still behaving like a nozzle. This means that the smaller the orifice, the higher flow resistance (and more pressure required to overcome). A larger nozzle will reduce the flow resistance, and you will see some improvement to flow rate, assuming that the heater is able to keep up, it should actually be a pretty meaningful boost in extrusion rate (in volume/time).

WRT a nozzle, Bernoulli's principle basically states that the pressure prior to the nozzle will be higher than after. Closer the inlet and outlet of the nozzle are in area, the smaller the pressure difference. And that keeps with the above. The bigger the nozzle, the larger volume of plastic you can push in a given time.

[bobbyshaftoe]

Cloning is not necessarily "bad" for a diy realm. At some point, all airplanes have wing.

[gloopann]

You don’t understand Bernoulli’s principle, the pressure is lower when the orifice is larger.

[RomanoPRODUCTION]

No Controversy ⭐⭐⭐⭐⭐
Humility ⭐⭐⭐⭐
Technical content ⭐⭐⭐⭐⭐
Nice vidéo, very enjoying. Have a nice day.

[Fredjikrang]

Those gear teeth are not machined. The most common way to make a gear like this is to use gearstock, which is a long rod that has the teeth formed into it. These are then cut to the face width that you need. Those marks on the side of the gear are almost certainly from the cutoff process on a lathe. I'm guessing that they aren't even having a custom face width manufactured and are instead just using off the shelf parts.

[jjmatteo]

Thanks for showing the REALITY that we can find with those extruders. Even with our own mistakes included .Noone show this on youtubethose these days. Thanks for being REAL,

[gamezxtrem]

i was a machinist in the military and sometimes a gear that is to spec needs to be meshed with a mate gear to smooth out the jankiness.

[lesptitsoiseaux]

Eccentric unwashed gears requiring manual sanding is the best you’ve ever seen?

[bcarroll]

Bernoulli's principal is referring to velocity, not volume. While the velocity of melted filament flowing out of the nozzle will increase with smaller sizes, the volume of filament does not. If you went to a larger nozzle you would have lower velocity on the output of the nozzle but your volume per second would increased.

Larger nozzle = higher volume

[MichaelJHathaway]

Thanks for showing off my products. I actually use TinkSeal on my Bondtech gears. All my rails and bearings are packed with TinkSeal. I use a small painter's brush to apply it. Works great on metal to plastic gears, resists drying.

[brandoneich]

Nero 3dp did a live stream of this and didn't like the machine quality of the gears, and the fact that there is no tensioner for filament tension. He has multiple screw come very close to getting stripped and the hobbes gear that is not supposed to float was floating. And couldn't rigidly mount. I take it you didn't notice the same issues, or at least, not to the same degree?


Edit: Also I wonder if it is like your mindga and it needs to be screwed in just right ( like if it is moved like 1mm slightly to one side it would not line up the filament path, but on the h2 perhaps the issue isn't the filament path but rather gear alignment)

[lazarjovic]

15 mm/sec of extusion is about is about 36 mm^3/sec (area of filament * 15 mm/sec), which is about the max for a Volcano style hotend (35-40mm^3/sec), a V6 style hotend maxes around 10-15mm^3/sec

To calculate how much you are pushing out, it's a quite simple formula: Layer height (mm) * extrusion width (mm) * print speed (mm/sec) = flow (mm^3/sec).

[Tphen]

"It moved freely before I took it apart."

[frankmustakas]

for the record those are not machined gears inside the extruder the gears were created via process of (sintered powder metallurgy) not the same as metal injection molding its a bit more like casting but can produce hard alloys the lathe marks you see on the side is the clean-up pass / clearance pass this is also y the shaft has tight spots in order to machine those gears even in china the price would be very high

[Dave_the_Dave]

It's great when parts are so well machined and the tolerances are so tight I have to spend an hour filing it down so there's enough play for it to move freely. Great design.

[bratwizard]

I *do* read the one-star reviews. I want to know what pissed 'em off.

[FrankBocker]

Half hour extruder review, but no prints?

[jmtx.]

Definitely jumping the gun by saying this is the "best" without even doing any prints with it. Looking forward to seeing actual print testing for flow and efficiency of heat dissipation.

[Dualecosse]

I have two, and I have found that after an hour of running everything runs much easier, it's much the same as with the omnia extruder where you had to run a special g code file to get those gears to mesh properly