Is a sub 1 min 3dBenchy possible? Split Hotend Engineering and Testing! (Episode 3)

[@Roetz40]

Name the CMM Printer BY REPLYING HERE: Giveaway talk @ 43:00, here in a nutshell. Whoever comments the name with the highest number of upvotes, gets send a package by me, containing: - Some unique parts of the CMM, I have some ideas but not 100% decided - A spool of my favourite high tech Filament - Some random goodies ill make up on the fly - The honor of naming this machine... :) International shipping! Im open for anything :)

[@tebla2074]

benchinator b1000

[@ZappyOh]

Name: _Alternado_

[@BogdanS92]

BenchySlayer9000

[@niemanddings9517]

AirhogV{Whatever Volume of Shop Air this ends up using per Benchy}

[@Wuast_3D]

BenchySupercharger, give that damn benchy a turbo xD

[@Bapate-rh9be]

Polymer scientist here: 1. Meting plastic can be greatly accelerated via a mäander, copper or aluminium fins that start small and extend further into the plastic the farther it went into the hotend. I manufacture these using a Fretsaw with a metal blade, which can actually be fittet throught a 1mm hole: Drill a 1.2 mm hole from the hotend sinde, a cone that starts at 2mm at the solid fimanet side and cut 6 veins into the structure using the fretsaw. 2. Plastic always has laminar flow: Mixing can only be archived with socalled mixing elements: Mixing elements divert polymer flow multiple pathes, than part these pathes again and recombine a parted path with the parted path from another path. I manufacture these structures via the use of triangles in a tube: The first triangle spits it into 3 path, the next triangle has a 60 angle thus parting it differently. These mixing elements are also necessary for fast polymer melting as the extremely poor thermal conductivity can otherwise lead to solid elements reaching the nozzle. They also have faster self cleaning time because they shorten the time distribution of material moving throught.

[@charlesstaton8104]

I think you are definitely on the right path! Youre going to love the longer melt zone and the filament path going directly through the block with no separation between barrel and block is definitely the way to go. A few suggestions for improvement from here (please note the suggestions come from first hand experience, not untested theory) 1. Now that you are exploring longer heating zones, I think you will find that CHT concepts are less useful. CHT is a workaround for a deficiency in almost every hotend (laughably tiny melt zone) and once you correct that deficiency then CHT geometry becomes just an obstacle. Look at industrial extrusion lines, they have a barrel a meter or more long, because that's how long it takes the plastic to go from solid to fluid. In 3d printing for some reason we think we can "zap" it from solid to fluid in a mere 10mm. WTF?! No! It doesn't work that way! Why do we keep doing this? You see now how much better it is when your plastic is actually given enough time in the hot zone to properly melt. Once your melt zone is sufficient and you're hitting 100mm³+ numbers, compare CHT nozzles to plain brass. I find plain brass flows 20-30% more than CHT with a 90+mm hotend. Long, straight, unobstructed filament path through the melt zone is what works best in my experience. 2. Still too much thermal mass. You can see at around 40:09 the temperature starts dropping with the rapid extrusion and can't keep up. It is technically possible to tune for this but it is very tricky because the tuning needs to be done *_while you are extruding at such high speed._* Keep in mind we typically perform auto tune at rest condition which only lets the system experience unrealistic operating conditions during its learning phase. By doing this we are setting it up for failure at high speed/high demand. But it is convenient so that's what most of us do. Tuning while running high speed is wasteful and plagued with problems but doing that is the only way the autoune can "feel" the actual dynamics of the system when it is experiencing those conditions and make appropriate corrections when running that speed. I have gotten high mass hotends to work at high speed by tuning while running and by manually adjusting the PID but found that once you are finally successful and it works well at high speed then it will become unstable at rest or low speed. The answer is to (dramatically) lower the thermal mass and increase the heating wattage so that heat loss is experienced by the thermistors almost instantly when a high volume purge is initiated, and the heaters have enough testosterone to almost instantly replace that heat even at high demand, as it doesn't "feel" much different to the heater than being at rest. 3. The old "drill a hole and insert a heating cartridge" paradigm should be retired at this point. Especially if you are only heating from one side. At the rate you are extruding, you are rapidly drawing all the heat out of that block and it is only being replaced from one side. One side of your bore is colder than the other, and that's why your filament is exiting sideways. Not a clog. You need heat applied from the outside around 360 degrees. CHC heaters have yielded superior results for me. 4. Your extrusion tests are not realistic and therefore the data you are basing decisions on might be irrelevant. Are you ever going to actually run with 40% underextrusion? Maybe for this speedboat stuff, I don't know. But for me, as soon as I hit 3% underextrusion the test is over. When I say I am hitting 120mm³/s, that is the number I am able to run at 3% underextrusion, and then I take small steps back down until I am once again

[@aleksin92]

About 2: Have you looked in to danger klipper? It implements Model Predictive Control that should help to predict the real power needed to keep the temperature stable

[@ThantiK]

Industrial extrusion lines are made for something completely different -- to keep a large volume of thermoplastic molten for the longest period of time, so that it can flow into injection molds. You need a lot more volume to fill an injection mold because you're doing it all at the same time. It's also laughable that you praise yourself on point #5 about increased surface area for better melt control, but BASH CHT for...wait for it... creating a nozzle with more surface area for better melt control! It's like you get it, but don't at the same time.

[@charlesstaton8104]

@@aleksin92 thanks for the tip! No, it was mentioned the last time I brought this up but I haven't had a chance to look into it. I do need to investigate this "danger klipper" as there are probably multiple things I could learn from it and I only just realized it exists. But TBH this issue isn't at the top of the list that I would like to learn, because if it works, it is a software workaround for a sub optimal hotend design. As far as I know I already solved the core issue. I no longer have the issues I described and I won't be going back to sub optimal hotend designs. The concepts I described here and in comments on his previous videos will solve the issue without needing a specific obscure firmware; will work on Marlin, whatever. Maybe Mr. Roetz will find the danger klipper software solution helpful though, if he wishes to stay the course that he is on.

[@charlesstaton8104]

@@ThantiK i didn't bash CHT, I reported test results. A rough bore does not extend into the filament path and block flow. It's not the same thing. And I'm not sure why you sound so hostile. Did I say something that offended you?

[@Roetz40]

1. Yee, cht may be a downgrade with that long of a heating zone and splitting geometries already integrated. It will definitely add more friction and back pressure to the system 2/3. You're right, the heater placement may be the reason the melt wants to wander off one way. Will fix that for future versions. In this case it was opportunistic for a test setup. In this particular setup, the heater was out completely and I started with an already -25° hotend without further cooling. 4. Well I don't agree completely. It was not my goal to (and I haven't) stated, that this hotend was able to run 125mm+ consistently without under extruding. I was just plotting the results. With an extra night if sleep, I'm pretty certain that MOST of the under extrusion is due to the pusher assembly partially slipping. At the end I pushed the lever arm down with my fingers and the numbers were way higher than before. These were my first extrusion tests and I'm aware that there are lots of things to improve. But I guess it gave me a really good starting data. Also: Speedboats are (at least to latest data) printed with a fairly constant extrusion speed only exceeding +-20% of flow. So I think it would be fairly easy to compensate for the under extrusion value 5. will try that, interesting observation. Maybe that is again, increasing of surface area?

[@leroymay8156]

I think a good name for this printer is "Minuteman". Because sub 1 min Benchy and of course also, "weil er abgeht wie eine Rakete". (Which is German for "because it's fast as a rocket").

[@Roetz40]

@leroymay8156 Gratuliere, du hast gewonnen ;)) bitte schick mir eine Email/PM/Discord!

[@802Garage]

Great name!

[@jangrewe]

@@Roetz40 I think "Stolzmonat" idiots (see his profile picture, the "Fäkalien-Flagge") should be excluded from any giveaways by default. #NoAfD #FCKNZS

[@stocki_esy625]

The filament going to one side when extruding at very high flow is not because of a clog. It halpens when the polymer chains in the plastic are not fully melted. The plastic is then not fully plastic, but rather keeps some elasticity. Because of that it springs back after the hole in the nozzle. This makes it go of to one side

[@christopherleveck6835]

If this whole machine is built specifically to print a 3dBency as fast as humanly possible.... Then take advantage of the fact that you know EXACTLY how much material you are going to use. Make a chamber to premelt the plastic. Then use a ballscrew mechanism to INJECT the plastic directly through the nozzle. You can create as much pressure as you want to get the job done. The material can be consistently heated to a very exact temperature. You only have to maintain it for less than a minute. Maybe A LOT less. And you dont have to worry about stepper motor driving the filament or skipping.

[@BlackHeartScyther]

I was thinking the same, its basically the same mechanism as the cocoa press chocolate printer, just at much higher temperatures. I think the stopping point would be the cooling, but would definitely like to see an attempt in this direction.

[@BlackHeartScyther]

Alternatively, the piston could be driven hydraulically instead of a ball screw. Theoretically if you had a plastic compatible hot hydraulic fluid, you wouldn't even need a piston head.

[@HonestBrothers]

@@christopherleveck6835 this wouldn't abide by the traditional rules. Actually, now that I reread it, I think it does. I need to learn to read. 😅

[@theonly5001]

Add to that, you know the amount of energy you need to heat that material. Use a buffer to fill with multiple hot ends. This way you have space to arrange your hot ends in a good way.

[@Roetz40]

There a already drawings made from a mechanic on the discord for that exact solution. It is a suitable solution and would be crazy fast. Thing is: I do have loads of experience in this field and I know how big of a project it is to build this from the ground up. How many episodes do you want to see? ;D

[@amusicmorning9190]

This series is awesome, looking forward to it every week

[@Fabian3331234333]

German engineering is back at it again!

[@Latrocinium086]

The viscosity is always going to lead to a fairly laminar flow. It’s the same reason we can use mult/dual/tri-color filaments. Your setup is going to do same, the question is does it bond together fully or you’ll need to use some type of agitation like a screw extruder.

[@Volt64bolt]

CMM -> BMM, the Benchy Making Machine. Nice and simple, and relevant to the machine.

[@MrCoolstopmotion]

Love your video! Really like the speed of the uploads and the way you present everything so clearly. Perhaps making n extruder that combines the last design and this one together. Multiple filament spools being driven into a split block. You can now do smooth transtions inside with your split block design. To get more pressure on the filament you can use larger gears to grip and push the filament but also potentially multiple gears to grip onto it with a larger overall surface area

[@marvintraxel6955]

Maybe have a large Reservoir of molten plastic and find a different way to stop the extrusion, maybe a small plug at the tip of the nozzle that comes in sideways. So you could have high pressure molten filament.

[@BlackHeartScyther]

If you have the molten plastic in a piston, then the stopping can be done through retraction, once pressure is removed, the plastic stops flowing. The piston could be driven with a ballscrew or threaded rod using the same stepper motors.

[@BlackHeartScyther]

Alternatively, the piston could be driven by a hydraulic fluid and the steppers drive a pump forwards and back to do the extrusion and retraction. You wouldn't even need a piston head if you used a hot, plastic compatible hydraulic fluid.

[@narenku6759]

I just discovered your channel through the previous video, and I think it's fantastic! I really appreciate the machining processes, the detailed explanations, and the step-by-step breakdowns. Keep up the great work! And i guess you simply call it "justafaster1"

[@dRepby]

I think the 8-shape worked better just because of the larger surface area. You don't have to limit yourself to a cht-like geometry with round channels since you're using a split part, but continue to complicate the shape and increase the surface area more and more. You could try gradually tapering the channel into a very narrow ellipse shape so you don't have to deal with the core splitting issue. Great video! Keep pushing the boundaries of what is possible and what is achievable!

[@MarcStollmeyer]

You should call it Event Horizon. Crazy powerful, crazy small build volume, and it’ll be quite the event if & when you accomplish a sub-1 minute benchy.

[@ThreeAngrySquirrels]

I love the use of capstan drives.

[@JakobDam]

This is amazing - and great progress in a short amount of time! As soon as you settle for the best extruder-hotend setup, you can dial in the algorithm in firmware and ooooh I'm so looking forward to see how that sub-1m benchy will look from then on, with incremental updates to the architecture!

[@Onhaey]

Most of this is over my head, but still fun to watch. Why not use a hydraulic press into a container of melted filament, if you can move the bed fast enough there won’t be a need for retraction lol

[@pmcquay1]

You've basically made a coextrusion head, there is no mixing going on because there is no turbulent flow (because turbulent flow is very hard to introduce in very viscous materials), but I dont see that thats actually a problem. The plastic is bonded together just fine, its not like it will come apart. Fun fact, if you have a cht nozzle, and you run some of that multicolour coextruded filament, it doesnt mix the filament, because the flow is still laminar. Cnckitchen tested that.

[@awkwardsaxon9418]

such a cool project. love the machining footage too

[@murk1572]

Considering the extrusion speed, just call it Soft Serve Printer or Softeis Printer

[@fritzwalmrath4057]

Please name this: "Itsy bitsy teeny weeny high speed benchy print machiney" Would be hilarious

[@zarster]

Name: The Benchypress

[@NiksSofa]

If you really want to go for it, i would suggest: - 3 hotends ( or how ever many you want really) - those feed into a auger ( transporting screw, not sure of the name in english) - that sits in a heated body and pushes stuff out of the nozzle and mixes the filament. I would love to see that.

[@simontratter2434]

That is a really good Idea. So It is kind of a mix of FDM and pellets extruder

[@bdykes7316]

I would recommend extending the hot end clamping faces around the clamping bolts to reduce bowing the two halves apart in the center of the channel.

[@Vez3D]

So sad this technique is patented :(

[@NathanDavidDodd]

Agreed. I am very familiar with the situation. And live in it. But don't quite understand it's basis. Because for filament production, electrical wiring covering , etc. This has been done in the 1970s and 80s (as far as I know, but I would bet the tech was introduced in or around ww2. With the same principle keeping it relevant. ) there was quite alot of innovation at that time in the new field. Sure it was called weedwacker string. But it was 1.8mm or 2mm nylon usually Then 40 years later it's patent is revolutionary nozzle geometry. Ouch. I do understand intellectual property. And patents. OK. Times are in your favor. For all of time, nobody cared about patents. Now is your chance to capitalize. Or castrate... 😂 . But in the end, I gotta admire the commitment of either side in my opinion.

[@HonestBrothers]

@@NathanDavidDodd how are you allowed to patent a non-novel idea? Also is the CHT patent only for nozzles?

[@lassikinnunen]

​@@HonestBrothersyou can patent almost anything nowadays, being able to defend it is an anothet thing entirely. If you find an old patent you can use that to invalidate the new one. Food processing has had most extruder nozzle area possible designs patented ages ago.

[@claws61821]

​@HonestBrothers Simply put, sloth and bribery. The PTO staffers don't care that the law states that unoriginal stuff is ineligible, and patent judges like money.

[@HonestBrothers]

​@@claws61821so traditional legal bloat

[@JoeMalovich]

When it goes off sideways that's an incomplete melt. Can you design a hotend that shears off the outside molten layers?

[@zockex6424]

Schichtschieber name in german, translated roughly into "Layer Pusher"

[@DevilZcall]

Die Filament-Orgel The filament organ Due to its ability to drive 1-4 filament „registers“ in parallel

[@_tooks]

These videos are fkn awesome, glad I subscribed and keen to see the results 🏆

[@AndreRuiz]

this is awesome work. Looking forward for the developments.

[@EdgePrecision]

Why don’t you put a small silver or copper insert in you split mold to transfer the heat to the middle of the split path better?

[@Roetz40]

Interesting idea. I'll check final design if it's easier to make an insert or machine it from a billet piece. But using silver would be dope

[@truey90s]

With the material leaking past the threads could you add a tapered face on the nozzle and matching one inside the hotend like a hydraulic jic fitting

[@floriankosch7624]

With the split hotend design you could machine a meltzone that transitions to an oval or even a rectangular crossection. This flatter crossection should have a shorter path for the heat into the plastic. Thank you for your interesting video!

[@chernogorsky]

If space is not an issue you may consider using standard nozzle cht insert before the nozzle

[@calinserbanspanu]

Machining the paths on haves or quarters of the hot-end opens the possibility to do more intricate designs and prologuing the filament path. If doing the 8 figure with multiple loops, it might be possible to insert a heater in the middle of the filament path (by controlling through design the shape and size of the island left in the middle of the flow) thus eliminating the cold spot and increasing the capacity of splitting of the filament. The heat application will be very close to the filament path. Another possibility is going with a round, middle slug containing a heating element and machining downward spirals in the outer wall of it. The slug can also be 3d printed and only the filament paths to be polished. Like this there can be made multiple helical and parallel paths that can process plastic from a single (split) or multiple extruders . The slug is inserted in a exterior jacket with that can also be heated. Regarding the problem of backflow that you have mention in the previous part, you can try using a tesla valve to restrict backflow.

[@justinpedersen9174]

could you pre-heat the filament before extrusion so the hot end doesn't have to work as hard?

[@callen_grigori]

The Bulldog Amsterdam Nice.

[@hanswurstusbrachialus5213]

Would like to see a copper insert like the chinese cht versions (which i think are just better and easier to make) Also this can be scaled to fit more channels.. maybe 5 would be nice? :)

[@kushpacsmike]

can't wait for the next episode!

[@jaysonlee8625]

Can you use a piston extruder or an injection molding setup? We will need quite high pressures to push all that material through your nozzle. Since you only need enough material to print a benchy, you wouldn't need a lot large cylinder.

[@OZtwo]

Very cool! Just started watching your videos and am more interested in if you could make a RGB type printer as I been playing with the idea in my mind but having no clue what I was thinking about. :) But I can't wait to see a 30 sec Benchy print!

[@excitedbox5705]

Have you considered drilling a cone shaped filament path with an insert to split it into 4 paths up to the nozzle. Depending on how close to the orifice or thin you can make the bottom face of the nozzle it may add an option for variability to the feed pressure. Sadly you are nozzle size limited because it would be impossible to get a splitter insert pointy enough to fit into the nozzle opening.

[@o1ecypher]

love the channel, but do you have a surround sound version of the intro?😆 i really do find it funny. keep up the great work

[@orphax1925]

the non mixing filament is not a problem, the same laminar flow properties are used for 2-3 colors filaments

[@refusalspam]

Is it possible to add a heatpipe to improve the conductivity to the splitting section?

[@codyhufstetler643]

I wonder if you could get more filament pressure with 2.85mm filament. Of course heating into the center becomes a problem again - although it would spend more time in the hot end for the same volume of filament?

[@ellabun]

You're really smart and clearly know a lot more than me about almost everything in these videos but damn I could see that filament pushing up the other chambers from day 0 xD

[@Roetz40]

Hehe yes. In retrospect everything is in plain sight. In cad, everything looks different

[@oaba201]

I think to push throgh more molten plastic on the same size nozzle. You have to use a screw (like in the injection moulder) to get the required pressure. Or even mix the separate filaments.

[@willemstigter6384]

Did you measure the rotation distance for the extruder while it was hooked up to the hotend? because that could cause the increase in output when the resistance is decreased by a better heating block.

[@Roetz40]

Yes I did. It checks out with all the other measurements

[@lnfotron]

I just had a crazy stupid idea, what if instead of using complex geometry to put heat faster into the filament, what if you used a magnetron to heat up the filament using microwaves?

[@GatorGlider]

Do you have to use 1.75mm filament in the speedboat rules? Could you make your own thicker filament, like 7mm diameter filament, instead of combining 4 into 1. It might be easier to build your split mold heat block to accommodate the larger diameter filament.

[@ianloy1854]

Just a thought about cooling - a CO2 fire extinguisher. NOW DANGER CO2 is not great to breath in. On the good side the gas coming out is actually freezing - that is the white stuff you see its dry ice at a temp of -78C (-109F). So if you have a box around the system and spray into it you have some really nice cold "air" to cool things down.

[@simontratter2434]

I think water cooling would be more capable of transporting heat away?

[@ianloy1854]

@@simontratter2434 It absolutely would be, 5X better in J/gC then considering their density water is ~ 1000X heavier than air, so overall you have around 5000X. But getting everything wet becomes a problem when it comes to having the layers attach (I assume).

[@Shadoweee]

Name idea - PlastAir. Sounds kinda like a blastair and as we know their projectiles are really fast just like this printer. It's a combination of two key components to this - plastic - obviously a material it uses to print with and air - used for creating the air cushion for the bed and cooling all the components.

[@BlackHeartScyther]

For the first prototype with the 4 filaments, if I understood correctly, while extruding the filament doesn't get stuck, only when it stops extruding for even a second. If thats the case, then could you get it spitting out filament and tell it to print a benchy? Not being able to stop and filament not uniformly mixing doesn't effect the ability to print with it, particularly at the rate of printing to get it under 1 min.

[@leobla744]

You could flatten the filament in the hotend to increase surface area without splitting and maybe even not fall under the patent :)

[@FullSpeed_only]

Is there Data for a broached Hole in a Star Shape and a simple Threaded Hole?

[@butre.]

you're already running into the same issue I am, where you simply can't shove more plastic through the tiny little 0.5mm hole. the plastic kicking off to the side so severely is a dead giveaway. speed benchy leaderboards requiring 0.5mm lines max and therefore 0.5mm nozzles puts a huge speed cap on them.

[@reid-dye]

your first hotend reminds me of the old Diamond hotend

[@jayliu496]

In the hotend instead of a straight line can you try a squiggly line ~~~ before the splitter? I think that way the filament's solid core can push away the molten sides and get melted. When you start adding more filament lanes I think to encourage mixing asymmetry will help. If everything is the same amount of melted I think the flow will be pretty much laminar and it will be difficult to get mixing. I think first you should try some more testing with just 2 filaments and trying to get them to mix. Maybe feed one filament fast and the other slowly can cause some turbulence and mixing.

[@U_Geek]

I don't think the color not mixing is a problem. You are melting the plastic it is just not mixing the pigments exactly like coextruded 2 color filaments.

[@scruffy3121]

Flex honing should be a easy and "cheap" way of improving internal channel surface quality. (not sure if they are available in that small sizes though)

[@alexbuckley1215]

what about turning it in turning into an injection moulding type extruder since it only moves up in z?

[@yagoa]

I would mill a copper X with sharp edges on both ends and solder it into an all copper nozzle heater-block combo

[@jangrewe]

"The Bulldog"? Looks like somebody has been to Amsterdam! ;-)

[@leonardoquirino7951]

Hello there! Just an idea, why not make a built-in tesla valve in the heat block to prevent the back flow of the molten filament

[@mikeyearwood]

Pulverize CMYKW filaments into fine powders. Feed them with a drill bit in capricorn tubes. That should give you many color options.

[@queenA6db]

kind of a silly idea, but what if you were to skew the speed benchy rules? a "0.5mm nozzle" is somewhat vague as to what shape it is. could you do a square nozzle for more throughput?

[@mrvolucris1863]

39:57, I don't think 80W of heating is enough to extrude this amount of filament continuously. I ran into issues with a 40W heater cartridge on volcano CHT hotend at about 30mm^3/s (as far as I remember) with the temperature creeping down from what it was supposed to be at.

[@tibr]

How many watts are your heaters?

[@bfx8185]

Don't you need some kind of chamber where it is mixed?

[@ErtsenPlayGames]

Around 10y ago +/- i used those big nozzles with radiators like one in 3:00 ,it was called "multi colour" , redrilled it and printed "fast" (10y ago) but still not as good as brass rod wraped in nichrome with long melting zone (back then of course) PS Construct3D will have nozzle like that soon :)

[@proginx]

Try a converging diverging geometry the weird increase In flow on the “8” nozzle could be related to turbulent flow past the second knife edge improving the mixing of material

[@pizzahut1892]

Why does mixing the filament matter?

[@chrisis4933]

I'm no expert, but would it be possible to use an induction heated hotend so that the filament splitter would be heated from the core so that it would be possible for you to get a higher flow rate at a higher rate of extruded filament? Or would the induction heater just heat the material more from the outside?

[@Roetz40]

I think there is some calculations going on the discord which kind of frequency you would need to heat up filament ;)

[@chrisis4933]

@@Roetz40 uhm probably frequency high enough for induction (induction formula: U(t)=N*dphi/dt ) and also low enough so skin effect doesn't take place but skin effect is also material dependent. There is a Company (Plastics) that made one but it's not really high flow and uses only a thin steel pipe (probably becauss of the skin effect ) that is induction heated.

[@johnyoungquist6540]

An injection bolting machine would easily fill a benchy sized mold in probably a second or less so the extrusion method the machine use is capable of tremendous flow rate more so than what you're looking for you might explore what techniques they use to extrude the plastic and possibly apply that to your application.

[@theboz1419]

Another way would be to have a screen and a plate that has many holes the holes are drilled in such a way that makes the plastic mix. The outer ring of holes go towards the middle and the holes in the center move material to the outside flow.

[@JasminUwU]

Mixing something this thick would take a lot of back pressure, it's probably better to not even try

[@theboz1419]

@@JasminUwU hence a gearpump would be best, that way you can control the back pressure and you will get a very good mix in the gearpump

[@theboz1419]

Infact, it has already been done, or atleast there is a youtube video of someone doing a gearpump 3d printing extruder for high speed extrusion

[@JasminUwU]

@@theboz1419 I'm not sure why you would even want to mix them? It wouldn't make the printer any faster.

[@theboz1419]

@@JasminUwU true,

[@802Garage]

I know you already picked a name for the printer, but I did want to suggest a funny name for the extruder itself: Schadenstruder.

[@benbertheau]

Quad BenchieBlaster

[@Chaminox]

Nice

[@jbrownson]

exciting project, thanks

[@iopfarmer]

Love it! I want more!

[@ChriFux]

Why do the filaments even need to be mixed in the first place?

[@ezrakornfeld8436]

30:16 damn that caught me off guard

[@velvia7880]

Use two super volcano heat cartridges? :D

[@willkeinerwissen2283]

You might want to change the filament path gradually from round to a + shape and back in the hotend instead of two round paths. That way, instead of trying to split the filament down the middle, where it is the coldest and hardest, you deform the softer outer part. Original idea: kzbin.info/www/bejne/jZDMm2BqnduIoNEsi=wmCLqomOaF51-Mc1

[@xpim3d]

Why does the extruded volume curve (green) went up?

[@Roetz40]

That's the question. My suspicion is, that my gcode wasn't made for this geometry and I weighed additional material from purging before. But still not entirely sure

[@pepijngoes537]

could pellets be better, or does that not work?

[@overengineering6096]

Please, anyone, give this man a KERN CNC milling machine! 👍🏻

[@aaronhambek6362]

I have to ask, why not just use 2.85mm filament? it's roughly 2-3x the cross sectional area of 1.75

[@meansq]

what about giving up on mixing and just have the 4 nozzles come to almost a point at the surface instead of inside the nozzle. then least resistive path would always be going out of the nozzle

[@Roetz40]

I like that thought!

[@bjarniharaldsson2798]

I suggest Sleipnir, the name of Odin’s 8-legged horse

[@maxmartinweiland3738]

The Benchynator

[@DavidJones-ws2vz]

Looks like Frankenstein's monster... Frankenstein could be a name

[@luke.perkin.online]

I realise it's a really dumb idea, but couldn't you just have a hot syringe with 50g of liquid pla in it? Then it becomes a recharge/tool change issue?

[@Roetz40]

That would be possible. Though it is something entirely new and that usually comes with a thousand initial problems :)

[@theboz1419]

A KZbinr named Kevin Coulson has a video of a Gearpump extruder, that would be perfect for this.

[@travistolar5231]

deckingman on the reprap forums (and here on youtube) was also experimenting with a mixing hotend, but ultimately gave up. there may be some useful information in his videos or blog posts for you.

[@jvcubing6137]

Quadro?

[@jomoin]

Printer Name: Oppenheimer

[@girrrrrrr2]

why not drive all 4 extruders from one motor/one shaft? That should help resolve extruding at different rates issue.

[@JonMaier]

I wonder if a pellet based extruder might actually work better. This would give a higher output pressure and a high potential flow rate. The problem here would likely be oozing as retraction with a screw drive seems complicated. Im writing this at the beginning of the episode, I i really hope im not going to see him making a pellet extruder in a couple minutes 😂