My MPCNC made in China

New Home Forum Mostly Printed CNC – MPCNC Your Builds – MPCNC My MPCNC made in China

This topic contains 354 replies, has 42 voices, and was last updated by  Mike Pensinger 1 month, 1 week ago.

Viewing 30 posts - 61 through 90 (of 355 total)
  • Author
    Posts
  • #32212

    Barry
    Participant

    Digging the pvc frame!

    #32272

    Dui, ni shuo de dui
    Participant

    Seems to print really well now that I’ve found the correct settings!
    (keep in mind that this is a 1.2mm nozzle with 0.6mm layer height, of course you cannot expect the quality finish of a 0.4mm nozzle)

    It took 3 hours to print the round part and 2 hours for the other one.

    I’m building a mobile arm system for my laptop, those are the first two parts:

    The only thing I have to improve is the sharp corners. For whatever reason, it seems that the nozzle leaves a bit more material in each corner, which makes them a bit bigger than they should be. I’m not sure what parameter I should tune up here, any advice is welcome.

    #32280

    Barry
    Participant

    Blobs at corners is usually an over extrusion byproduct. Anywhere else and it gets smoothed by the successive layers, but corners don’t have anywhere for the extra to go, so blobbing.

    1 user thanked author for this post.
    #32316

    Dui, ni shuo de dui
    Participant

    I made my biggest print so far: 350 mm x 250 mm x 30 mm thing.
    This will be the laptop support.

    It printed almost fine, but I do realize now that warping is unavoidable without having a heat plate. I now need to find an easy and cheap way to make one.

    It took around 5 hours to print, 2 perimeters, 3 top and bottom layers and 20% infill.
    I really love that big nozzle stuff, printing has never been so fast

    @Barry, I thought about that, but I’ m not sure, because whenever I lower the extrusion multiplier the corners get slightly better, but the perimeters won’t stick together and will leave some gaps (see pic hereunder)
    I may need to check that it actually extrudes at 1.2 mm and not slightly thinner. Thanks for the advice !

    By the way, I would like to thank again @vicious1 for the forum improvements, uploading pictures is now so much easier ! Big thanks!

    1 user thanked author for this post.
    #32325

    Dui, ni shuo de dui
    Participant

    I just realized I forgot to put pictures of what I’m trying to do.
    Should look like this if everything goes according to plan.

    The goal is to be able to support my laptop. Maybe I will put it on the CNC or maybe I’ll hand it from the wall. Or maybe I’ll print 2 brackets and do an easily switchable system to be able to do both, I have to see if it works first.

    #32528

    Dui, ni shuo de dui
    Participant

    It’s working!

    So as it turns out, It is possible to build quite sturdy things out of 3D printed parts. I’ve almost completed my laptop stand and so far it seems to work perfectly.

    Just a few accessories to add and it will be finished.

    #32545

    Jim Hildebrandt
    Participant

    That looks like it works great, very nice design!

    1 user thanked author for this post.
    #32714

    Viktor Niniadis
    Participant

    Great work! You have inspired me to start own one.

    1 user thanked author for this post.
    #32772

    Dui, ni shuo de dui
    Participant

    Great work! You have inspired me to start own one.

    That’s great, I’m very glad!
    Wish you good luck with yours!
    You’ll see, it’s an awesome machine

    #32784

    Barry
    Participant

    Pretty cool! Needs the pneumatics replaced with a couple linear actuators and an arduino controlling it. Then a camera so it can see you, and keep the laptop pointed in your direction!

    3 users thanked author for this post.
    #32786

    Dui, ni shuo de dui
    Participant

    Pretty cool! Needs the pneumatics replaced with a couple linear actuators and an arduino controlling it. Then a camera so it can see you, and keep the laptop pointed in your direction!

    Haha, not a bad Idea,
    But creating the firmware would probably be very difficult, and programming is not really my strong suit… Mechanically it wouldn’t be a big matter for me though.

    But even If I was making this mod, I would keep the pneumatics because they compensate for the weight, so it would assist the linear actuators during their work, much less stress on them so they could stay small, use smaller/cheaper/lighter motors and smaller/cheaper drivers.

    I’ll post the 3D files of my laptop arm when it will be entirely finished, I just have to print a few parts to support and clamp the laptop in place securely.

    #33245

    Dui, ni shuo de dui
    Participant

    Well, I finished my laptop stand, it works fine, so I’m pretty happy with it. Just need to find some new bolts of appropriate lenghts and is should be all right.

    I had a few issues while printing a very huge part last weekend: the extruder was clogging during retractation. I narrowed it down to a too high temperature in the top part of the nozzle (the one that is supposed to stay cool).
    I tried to lower the temperature of the nozzle, but it didn’t entirely solved the issue, and at some point it was a bit too low to keep a high speed flow and good adhesion.
    Anyway, I wasted about an entire spool because of this issue. So I had to do something about it…

    That was my biggest part so far… too bad it ended up like that…

    So, the only option I’ve got now is to move to a more efficient cooling system. I decided to try to build a watercooled nozzle.

    So far, I’m experimenting to see if this works, before maybe building a more reliable thing (unless this one turns out to be reliable enough).

    I’ve just used two O-rings, an automotive silicon tube, a few couplers a pump and some tubes.

    I did a quick test yesterday and it seems to work fine so far. I manually tried to simulate lots of retractions with various parameters (retractation speed, retractation distance, time between retraction and prime, etc) and I never managed to clog it up. So, if this doesn’t leak I suppose it will work fine.

    Strangely, it seems that there is no available water cooled nozzle system available in China, I’ve searched for hours and nothing…

    Anyway, here is how my current prototype looks like:

    If anyone has experience with watercooled printheads, any advice or tip is welcome 🙂

    #33261

    Andy
    Participant

    I was going to suggest using copper brake line wound around the heatsink in a coil but looking at your fix i think yours is cheaper and if it doesnt leak it probably is more effective at cooling since the water will get between the vanes of the heatsink.

    I wonder whether if you made the heatsink vanes spiral or remake the heatsink like a spiral whether you might get better cooling as you wouldnt get water static in between the vains as it would direct the current of the water.
    Just want to say as well, love your work here, truly inspiring.

    1 user thanked author for this post.
    #33351

    Dui, ni shuo de dui
    Participant

    I was going to suggest using copper brake line wound around the heatsink in a coil but looking at your fix i think yours is cheaper and if it doesnt leak it probably is more effective at cooling since the water will get between the vanes of the heatsink.

    I wonder whether if you made the heatsink vanes spiral or remake the heatsink like a spiral whether you might get better cooling as you wouldnt get water static in between the vains as it would direct the current of the water.
    Just want to say as well, love your work here, truly inspiring.

    Thanks!
    Actually, the heatsink is just a normal E3D v6 one, I made not change to it whatsoever.
    I used 2 O-ring, one on top and one on the bottom, they have two functions:
    -Seal, of course
    -Act as a spacer, so that there is space between the big silicon tube and the nozzle for the water to flow, about 1 mm all around.

    Then, I have one inlet on the very bottom of the heatsink (which is the part where having the best cooling possible is the most important) and an outlet on top of the heatsink, so the water is forced to go everywhere, and even if there could be some static water in the middle it wouldn’t matter so much since the bottom is cooled directly.

    #33352

    Ryan
    Keymaster

    The cooling fan it came with wasn’t keeping up?

    #33353

    Dui, ni shuo de dui
    Participant

    The cooling fan it came with wasn’t keeping up?

    Apparently it wasn’t enough.
    When you print with a big nozzle, you need to crank up the temperature. Usually, when I print with a 0.4mm nozzle I print at 208 degree Celsius. But if I try that temp on the 1.2mm nozzle, the extruder motor cannot keep up and tend to miss steps, because it has to run much faster, thus lowering the torque (and currently I use the beefiest motor possible for this size). In which case I have two solutions, either run the printer at lower speeds (which is not the point of having such a big nozzle, because what I want is printing speed over quality), or setting a higher temperature to increase flow. So, I usually set the temperature at 220-225 degree celsius, which allows a very good flow, perfect adhesion and relatively correct quality.

    I tried a bunch of other things, like disabling the retractation, setting a very small retract distance value, tried different acceleration prime and retract parameters, different speeds. It sometimes made the problem less frequent but it always ended up happening at some point during long travels.
    This was a severe issue during my first prints, like the shifter bracket that I printed a few weeks ago, I managed to limit this issue quite a lot with fine parameter tuning, but I believe I reached the limit of what can be corrected by the software, since I print bigger things now.
    For example, on the big part on the picture above, travel distances can be as long as 800 mm. My travel speed is set up at 120mm/s which is about the maximum the Arduino can manage, but it is still a bit too long. And It probably won’t be the biggest part I’ll print in the future, the maximum theoretical travel distance should be around 1100 mm or so.

    Higher temperatures works very well to reduce load on the extruder motor whenever the printer is actually printing, but during long travels the heat is not evacuated by the filament anymore, the temperature rises so it melts the filament higher than it should inside the heatsink. Then when it primes again, the pressure applied to the partially melted filament makes it clog inside.

    Maybe a bigger fan could help, but I think the sure way to overcome this issue is to go for watercooling. I also plan in the future to use nylon filament, which requires even higher temperatures, so watercooling will probably not be an option at that point.

    Plus, it’s a fun experiment XD

    #33354

    Martin DB
    Participant

    About the over extrusion in the corners, have you put an eye in the linear advance feature of marlin? It’s supposed to solve this kind of issues.

    #33355

    Barry
    Participant

    Are you using 3mm filament or 1.75mm?

    #33440

    Dui, ni shuo de dui
    Participant

    About the over extrusion in the corners, have you put an eye in the linear advance feature of marlin? It’s supposed to solve this kind of issues.

    Yeah, I red about that last week and I even thought of creating a new thread to ask questions about this feature.
    I didn’t find any tutorial who explains clearly how to activate it.
    I suppose I just need to enable in Marlin and define a K factor, but I was still a bit unsure and I try to avoid reflashing my arduino every time, especially when it works fine already.

    Do you, by chance, know a good guide for this function?

    #33582

    Caduceus
    Participant

    Hey man, new here and really impressed by your build and its versatility, it’s awesome and i want one 🙂
    I have a suggestion for your heated bed problems that might work;
    Use a hot air gun to preheat the surface.
    Or, have a look at electric floor heating such as this;
    http://www.xagalaxycable.com/carbon-heating-film/infrared-carbon-floor-heating-film-thin-film.html

    Also i’m wondering if you could use it to mill a surface lower than the base, or will there be too much forces going on for accurate milling?

    Looking forward to seeing what you will pull off next, how’s the plasma cutter coming along?

    1 user thanked author for this post.
    #33583

    Dui, ni shuo de dui
    Participant

    Hey man, new here and really impressed by your build and its versatility, it’s awesome and i want one ?

    Thanks!

    I have a suggestion for your heated bed problems that might work;
    Use a hot air gun to preheat the surface.

    Actually the problem of warping occurs after at least 10-20 layers are already printed, so warming it up at the beginning wouldn’t help so much. The adhesion to the build plate is generally fine just using glue sticks, plus it needs to be easy to remove the printed parts after done, because those big parts put lots of stress on the glass while removing them, and I don’t want t break the mirror…

    Or, have a look at electric floor heating such as this;
    http://www.xagalaxycable.com/carbon-heating-film/infrared-carbon-floor-heating-film-thin-film.html

    Seems like a very nice solution, thanks a lot! I didn’t know those things existed
    The only issue I see is that it is limited to 60 degree C, which will be too low for nylon, but since I mainly print with PLA it could do the trick…
    I’ll check that, thanks again for your suggestion!

    Also i’m wondering if you could use it to mill a surface lower than the base, or will there be too much forces going on for accurate milling?

    The base is adjustable in height and you can even remove it and mill an object directly from the floor if your Z axis is long enough. But I don’t recommend you to try that, there will be way too more leverage, the results would be horrible, and you may even destroy the Z axis. Might work ok for 3D print though.
    But I really don’t know why would anyone do that. For what kind of project would you want the mill to have around 1 meter of travel? Keep in mind that it would need a crazy long cutting bit too, probably impossible to find.
    Could you explain why this question? Maybe there is an other alternative or maybe I didn’t understand what you meant

    Looking forward to seeing what you will pull off next, how’s the plasma cutter coming along?

    I haven’t tried again yet, I would like to build an enclosure for all the electrics and watercooling first, in case I blow up another arduino trying the plasma I would like it to be easier to maintain and replace. Plus I need to solve my ground issues and shield everything properly.
    I guess I’ll give it another try in a few weeks, I would really like to be able to cut metal parts,

    #33584

    Caduceus
    Participant

    Never checked the max temp of the film, my bad, but perhaps there’s something that does higher temps.

    To clarify, i wouldn’t want to mill anything 1Mtr below the base, maybe 5-10 Cm at most, what i would like to do is put the MPCNC on a table, and engrave/cut that tables top, hope that gives a better idea of what i’m looking to do.

    And what would be the max. thickness of different materials you could cut with the plasma?

    #33656

    Dui, ni shuo de dui
    Participant

    To clarify, i wouldn’t want to mill anything 1Mtr below the base, maybe 5-10 Cm at most, what i would like to do is put the MPCNC on a table, and engrave/cut that tables top, hope that gives a better idea of what i’m looking to do.

    That should probably work.
    You may mant to check the low rider for this application, I think it might be more suitable.

    And what would be the max. thickness of different materials you could cut with the plasma?

    This depends entirely of the plasma cutter used.
    I’ve purchased a cheap one, so I will be limited to something like 8 mm steel. That’s enough for me, but some more expensive cutters can cut 100 mm steel plates or more. Depends exclusively on your budget.

    So, this weekend I tried my watercooling system to see if it would make any difference.
    Well it turns out to work very well!

    Before that mod, I use to have big variations in nozzle temperature. Usually, the nozzle was fluctuating by about 6 degrees C (-3 to +3 degrees relative to target temp) all the time, with some big spikes during travel moves (+10 degrees C sometimes) and during high speed shell paths (-5 Degree C at worst). Those were an issue because I sometimes had missed steps during shell quick passes and sometimes had clogged extruder during travels.

    Well, the watercooling seems to make quite a big difference, since the biggest difference I got to see during printing was a +2 degree C, which lasted less than 2 seconds. The rest of the time I got a super steady 220 Degree, with some rare variations of + or – 1 Degree.
    So, the difference appears to be very noticeable.

    So far, my simple system doesn’t seem to leak at all, so I may keep it this way.
    Just need to find a better pump (this one heats quite a lot), and make a clean system.
    I call that a pretty good win so far, I’ll see in the long run if it works as intended.

    I printed those two brackets which are the first parts of a big enclosure that will house all the electronics, the water tank, pump, wires, etc.
    Still a lot of work to finish this, but in the end it will look a bit cleaner and make maintenance easier, with much better access and better cooling of the motor drivers.

    #33803

    Dui, ni shuo de dui
    Participant

    Hi Guys,

    Still working on my electronic’s enclosure.
    I worked on the bottom of the case and printed a few brackets.

    One bracket is for the connecting interface drivers/RJ45, while the other one supports the Arduino/Ramps. The arduino is just clipsed in place, so it can be removed in a few seconds if necessary, which can be convenient either to switch quickly between two different versions of Marlin, or to replace a broken one in the likely case that it will blew up again while I’ll test the plasma cutter.

    The brackets look kind of ugly because I didn’t have any cooling while printing since I have to design new brackets for my fans, plus I hadn’t tightened the print head screws at all, so it had lots of play and moved all over the place. Anyway, I don’t care, it still works fine.

    Just need to make one more bracket for the PSU and to receive my new watercooling pump and tank. I’ll try to make some doors using plexiglas and all this will be cooled using some big ass fans.

    Keep you posted!

    #33842

    Ryan
    Keymaster

    You are the clear winner for most elaborate build! I love it. But you need a label maker for all those wires to take it to a whole new level.

    1 user thanked author for this post.
    #33925

    Dui, ni shuo de dui
    Participant

    Haha, thanks!
    I was indeed thinking about that for a while, it’s sometimes annoying to find which wire goes where… I made some el cheapo labels for X,Y,Z and E wires using tape but I sometimes confuse the temp sensor and the fans…

    I’ll probably borrow one at work and label everything when it’ll be finished. ^^

    BTW, I found some 2 meters long wiring for the screen, with standard 10 pin connectors built in. I’ll tell you if this works, if not I’ll shorten them progressively until I find out what is the practical maximal lenght.

    #33926

    Barry
    Participant

    You might try wrapping the cables in aluminum duct tape. Not duck tape, but the real aluminum stuff. Computer modders do that for the pci-e extender ribbon cables. Seems to help.

    #33929

    Dui, ni shuo de dui
    Participant

    Also, I was wondering if it wouldn’t be better to change my motor drivers from the little pollulu to the intermediate TB6560 drivers.
    Aside from the extra power they can deliver, they seem to have optocouplers, which could probably help to prevent killing the arduino while using the plasma cutter.

    I still have a bunch of those from a robotic arm project I’ve done last year, do you see any reason why this wouldn’t work or why it wouldn’t be a good idea?

    #33930

    Dui, ni shuo de dui
    Participant

    You might try wrapping the cables in aluminum duct tape. Not duck tape, but the real aluminum stuff. Computer modders do that for the pci-e extender ribbon cables. Seems to help.

    I tried that but I’m not convinced since it is not really flexible. It has a bad tendency to crack while bending the cable. Also, the continuity tests shows that there is quite a bit of resistance when sticking one layer of aluminum tape to an other. I suspect the glue to not be as conductive as it should.
    Anyway, this seems to be the only solution so I’ll continue to use it…

    So far this is the only easy solution I’ve found to ground all the CNC before trying to use the plasma cutter again.

    I’ve also ordered some braided copper (the stuff used to desolder component from PCBA), I’ll use it to connect all the tubes to each others, should be more reliable than the aluminum tape.

    #33936

    Ryan
    Keymaster

    Not sure what is actually killing the board from the plasma though, So many things I don’t understand about that kind of electronics. I understand the basics but HF is magic to me.

Viewing 30 posts - 61 through 90 (of 355 total)

You must be logged in to reply to this topic.