I am just going to leave this right here…..



  • Okay, so I can admit I can tend to really resemble the typical A.D.D. kid where it occasionally looks like I am bouncing ignorantly from wall to wall to wall in search of a solution….Uhm...I think I found a pretty interesting solution 🙂

    So...Yeah...MiT got involved....They thought 3D Printing didn't need to take so long and thought it was a bit of a waste as it sat with it taking so damn long for everything. MiT looked at 3D printing as a brilliant potential solution to traditional manufacturing limited greatly by speed, specifically in regard to Fused Deposition Modelling (Copyrighted by Stratasys) and Fused Filament Fabrication which is (to my knowledge) not copyrighted or just open.

    So...MiT did this: https://youtu.be/8wVGaxgkmk4

    Then wrote a technical paper that can be found here: https://arxiv.org/ftp/arxiv/papers/1709/1709.05918.pdf

    …..GO! 🙂 Honestly....I do not care what it costs....I WANT IT! I am building my own ASAP haha 🙂 I am already CNC milling my own Hypercube evo from Thingiverse out of mainly 6061 But MiT uses AC motors, I'd try to use BLDC simply because I have that connection. I started doing the calculations for the torque and speed demands last night, the motors I was planning on asking Faulhabers to donate were REALLY EXPENSIVE, I was not concerned about cost. The motors I was looking at on paper were 24-48v 10,000 rpm two pole three-phase BLDC motors and 90% efficiency geared I think ~4.8:1 but the incremental encoder (only haha) went to 1056 lines per revolution, or thereabouts. To exceed the resolution of the encoder MiT used I'd need their absolute encoder which was something like 4056 lines per rev. The AC motors they used are less than $300 (without the drivers obviously) the motors I was looking at are a ton less inertia and the torque for the X and Y should be less than half of the motor's stall torque. I was thinking of overall power consumption, more than anything else. The motors they used were not geared in any way. Read the technical paper, it is quite interesting.

    Apparently, MATLAB could expedite the project by using FPGA and a High-Level programming approach. For anyone that is genuinely interested in this (close to $1,000 in software if I am correct in what I looked up), this is what I am referring to:
    https://www.mathworks.com/discovery/motor-control.html
    Video here:
    https://www.mathworks.com/videos/modeling-hdl-components-for-fpgas-in-control-applications-92060.html

    Is it a solution worth investigating? I'm all in regardless :]

    The reason I post this here is because I wouldn't have learned as much as I have and doing an internship with a BioMedical Orthopedics Manufacturer under the robotics engineer if it wasn't for what I've learned with 3d printing and with/from the Duet.



  • For once I found something worth reading that makes a fair bit of sense. Thanks for sharing. I'm not sure about the motion side - the youtube video is obviously a prototype so I would expect to see that it isn't perfect. There is obviously room for improvement to make the system less noisy and smoother. But, the filament heating aspect alone is exciting. It's very refreshing to see some real analysis of what is going on and what the real limiting factors are. Coupled with what appears to be a practical approach to solving the problems. The extrusion side is maybe going to be problematic in that it requires threaded filament but if the melt rate of the filament is fast enough so that there are limited back pressure issues, then a more conventional extrusion system may be sufficient without the need to use threaded filament.

    Thanks for sharing (and can I buy just the hot end 🙂 )



  • Haha I know right? It has PROTOTYPE written all over it, you see how many zip ties are on that thing??! Haha they have my respect for running that stuff that fast like that alone hahaha.

    I thought about the threaded filament part, what if you use a screw system custom made for that…pull the filament in rather than pull and push it through, ya know? I have some ideas to modify the feed system already....where the f**k am I going to find someone to machine quartz to optic quality???? Gilding it is not hard, but the infrared hearing is genius,..think it is possible to eliminate the need for a conventional headed nozzle with that? If it heats volumetrically....PWM should be able to accurately tune for that, no?

    I am going to do some homework on spectroscopy and do some proper calculations and create a few CAD files and run some simulations with a very expensive but educational thermodynamics and electron physics simulation software and see if I can come up with enough to get a grant or funding from the Faulhaber FabLab to pursue this further. I genuinely believe this could change everything and I have a few ideas on how :] Open-Source is a must in my personal opinion.

    Haha I am going to improve the design of the hot end once my calculations are done, I think I might stick with a 50W, that seems to work exceptionally well. I need support material though, no sense in doing it in my mind, retraction with that system CANNOT be easy...easier to duplicate a hot end (not cheaper) and with the speed that thing extrudes plastic I am thinking of a simple way to prevent/eliminate oozing...I would like to test it first.



  • While you are investigating hot ends, melt rates and the like, see if you can devise a way to actively (or passively) mix multiple filaments together. Currently there are no mixing hot end that truly mix filaments so what comes out of the nozzles is like stripey toothpaste. So that would be a winner.

    On the extrusion side, if you can melt the filament fast enough, there should be very little pressure against which to push the filament so current extruders would likely do the job. Current extruders are more than capable of loading or unloading filament very quickly indeed. It's only when you try and push against the resistance caused by melting the filament and then forcing it through a small orifice, that problems occur. Eliminate the resistance and you've already cured the extruder problem.

    On the movement side, it needs to be done in such a way that it is smooth and free from jerky behaviour. For sure it's possible to have very high speeds but if the movement is too jerky, then it won't print well. Don't forget that the viscous filament needs to follow the mechanical movement of the print head and because of their nature, streams of viscous fluids do not accelerate quickly, not do they bend sharply. So it's not so much about the ultimate speed that can be obtained, it's more about accelerating and decelerating up to and down from those speeds in a smooth manner. This is usually the factor which limits ultimate mechanical speed.



  • What about inter-layers adhesion? Extruding that fast won't let enough time for the previous layer to melt…



  • @fma:

    What about inter-layers adhesion? Extruding that fast won't let enough time for the previous layer to melt…

    To my understanding, the extruded material is hot enough to soften the previous layer. It apparently isn't much of a problem, the only issue they had with layer adhesion was torsional.



  • I can understand that. The flip side of not having time for the new filament to melt the previous layer is that the previous layer won't have had time to cool as much. I know from the limited testing I did with the Diamond hot end and 3 melt chambers that at speeds up to 300mm\sec, inter layer adhesion wasn't a problem.



  • Ok, thanks.



  • Smoke, i see that in all the facebook groups and people with low experience printing saying "I want this, plis put in marlin, blablabla"
    Read less smoke from fake news sites and take more time to learn with your machine.



  • @Cata:

    Smoke, i see that in all the facebook groups and people with low experience printing saying "I want this, plis put in marlin, blablabla"
    Read less smoke from fake news sites and take more time to learn with your machine.

    All true, but what bearing does that have on the OPs post? It seems that someone is doing some serious research into how we could print faster, largely by finding ways to melt filament faster, which is well known to be a major constraint. I don't see any fake news sites nor any requests for firmware features in the OPs posts.



  • In their white paper it says they used DC Servo motors.



  • @kgordon:

    In their white paper it says they used DC Servo motors.

    You are absolutely right! I thought they used AC servos! The motors they used are interesting, I am going to try to build one of these. From my understanding, they used an FPGA, I really do not like the idea of an FPGA because I know nothing about them. I have to finish machining the larger CoreXY I am building now in order to prototype this. I have access to slightly different motors so I will make a board more specific to the motors I have. Once I have a working prototype I will share what I come up with. Probably won't start working on this until March. Any and all help is appreciated.



  • @deckingman:

    While you are investigating hot ends, melt rates and the like, see if you can devise a way to actively (or passively) mix multiple filaments together. Currently there are no mixing hot end that truly mix filaments so what comes out of the nozzles is like stripey toothpaste. So that would be a winner.

    On the extrusion side, if you can melt the filament fast enough, there should be very little pressure against which to push the filament so current extruders would likely do the job. Current extruders are more than capable of loading or unloading filament very quickly indeed. It's only when you try and push against the resistance caused by melting the filament and then forcing it through a small orifice, that problems occur. Eliminate the resistance and you've already cured the extruder problem.

    On the movement side, it needs to be done in such a way that it is smooth and free from jerky behaviour. For sure it's possible to have very high speeds but if the movement is too jerky, then it won't print well. Don't forget that the viscous filament needs to follow the mechanical movement of the print head and because of their nature, streams of viscous fluids do not accelerate quickly, not do they bend sharply. So it's not so much about the ultimate speed that can be obtained, it's more about accelerating and decelerating up to and down from those speeds in a smooth manner. This is usually the factor which limits ultimate mechanical speed.

    I have given this a lot of thought over the past few weeks and I still do not know how to approach this problem. This is not an easy problem to solve, the measurement equipment these students had far exceeds the equipment I have at my disposal. This is above me and I am more than aware of it. I am going to attempt to get a few engineers that have the experience necessary to prototype this. This….might take a few....dozen revisions.



  • @Cata:

    Smoke, i see that in all the facebook groups and people with low experience printing saying "I want this, plis put in marlin, blablabla"
    Read less smoke from fake news sites and take more time to learn with your machine.

    I do not understand what you are on about. This is a proven prototype, with documented research and results, funded largely by Lockheed. This is a functional prototype. There are no smoke and mirrors….this exists already. There is a technical paper on what they found out, and almost how to do it. All I am suggesting...is let us try to find a way to copy this, and improve it where ever possible. Put your tinfoil hat back on, it's better you sit this one out, just don't be asking for help when we get it working.



  • I think what he's saying is whilst I like your enthusiasm for the unusual and experimental, nothing gets you further than getting on with building something and then showing us your build and prints. If you can jump straight into this sort of stuff then more power to you, but maybe you might need to just put an i3 together and print some stuff first. 3D printing is about as far from a pure academic exercise as you can get, and I say this now as an author of an article published about 3d printing in a peer reviewed scientific journal, designer of two unique printers and co-owner of a company making 3d printing products, I've a scientific background but I gained my knowledge with my hands on the kit.



  • @djdemond said in I am just going to leave this right here…..:

    I think what he's saying is whilst I like your enthusiasm for the unusual and experimental, nothing gets you further than getting on with building something and then showing us your build and prints. If you can jump straight into this sort of stuff then more power to you, but maybe you might need to just put an i3 together and print some stuff first. 3D printing is about as far from a pure academic exercise as you can get, and I say this now as an author of an article published about 3d printing in a peer reviewed scientific journal, designer of two unique printers and co-owner of a company making 3d printing products, I've a scientific background but I gained my knowledge with my hands on the kit.

    Why did I never respond to this???

    Forgive me for being absent from this forum the last few months, been busy with work. I do not doubt you or discredit you in any way. Did I know all of that? No, haha not at all 😆 nevertheless, a certainly respect what you are saying/what you said and judging from my overall tone back then, I probably would have disagreed with you. After some time had passed and I have more or less done exactly what you prescribed, I feel it is about time to readdress this topic again.

    Judging from the way you were talking, I imagine it's a pretty safe bet to say you most likely do not know what I do for a living. I am a CNC Machinist, am rather proficient in Autodesk Inventor 3D design and legitimately play with some of the best DC motors on the planet. I certainly know very little about electricity, electronics, motion control, programming, and the chemistry of thermoplastic extrusion relative to many other individuals here. I do, however, have the skills, intelligence, the majority of the tools, access to most of the equipment, probably the funding if I can get Mrs. Faulhaber on board with it (which is one of the reasons I would prefer to use their motors, they'd probably pay for it). When you think about it, regardless of what motors are used for this, or what the first version of this prototype looks like, all it's gonna do is pave the pave the way. If I have to spend a few grand and a few months or even years prototyping but the end result is the beginning of an epic Open-Source project that speeds up FDM/FFF 3D printing 7-14x, I'll bite the bullet, I don't mind. It would be nice to have some help with it though since as of right now I expect to be responsible for the whole damn thing. At the very least, if I can get high enough of it by myself where I can come here and say "here is how far I've gotten, I need help, here's what I got" then that would be a start. I realistically have the ability to make it into a reality with a little bit of help and as a direct result, I feel I have a responsibility to make it happen.

    I've designed a bunch of files for it, I'm on the third iteration of the hardware of the machine right now, some pieces are V5 but I have a vision. I'll put what I have up on github and post it here by the end of the calender year most likely, we'll see how far I get between now and then.



  • Perhaps someone that reads this might remember and could point me in be right direction or provide a company name or link or something.

    I cannot for the life of me remember who made the motors I'm thinking of.

    Someone built a 3D printer, or at least a CNC mill or something in one of these forums and used a motor company that was rather unique. The motor looked identical to the motors used in drones or quad copters, only they are a hell of a lot larger, just as efficient, and have encoders. They were relatively inexpensive and would be a fantastic choice for this type of application, and they weren't technik motors. I cannot for the life of me remember who made them, they really did look like hobby brushless servos adopted for an industrial style application. If anyone knows what I'm talking about, please drop a link, I wanna but them yesterday haha.

    Thanks in advance.



  • Are you thinking of odrive?
    https://odriverobotics.com/



  • @phaedrux

    I was literally just looking at that, $130 or $160 for that drive though?! I'm about to see if I can send that to OSH park or something. That sounds absurd.

    I want it, that seems excessive though.


 

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