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3D Printer General Chat

Discussion in 'Hobby Engineering' started by Spanos, May 26, 2021.

  1. FlyN

    FlyN Member

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    Hahahaha, wow...you heard it first here guys. Forget your fancy pants vorons, hevorts, stratsys's, etc. The ender 3 is the greatest-3d-printer-of-all-time. Owing to its superior single gear bowden system (be sure to replace that because you can be assured that the injection molding was poorly designed and will crack https://www.reddit.com/r/3Dprinting/comments/ex9s0k/ender_3_extruder_arm_crack/).
     
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  2. m3k

    m3k Member

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    very nice cube mate :) well done on the new build, the sherpa mini was a great choice- very lightweight yet powerful.
    Thanks for sharing. Seriously.

    agreed big step up - those wanhao i3 printers/cocoons were quite poorly made - ive seen many, and the Z smooth rods were not fixed correctly and had free play, and that was just the beginning of their issues.
    though lighting is very important when showing layer imperfections- obviously diffused side lighting will be flattering vs top down sharp lighting - especially with ABS which is very matte by nature.
    but consistently perfectly formed layers isn't what makes a printer great- I never said it did- i just thought it was a little ironic and kinda awesome for newcomers that such a cheap printer will out of the box print a little bit nicer than more expensive printers. ( in PLA )
    honestly surprised at how many users are straw manning what i wrote its kinda disheartening "HuRRr DurRr EnDer3 BesS PRinTur" - m3k
     
    Last edited: Aug 12, 2021
  3. millsy

    millsy Member

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    Well that was boring to read
     
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  4. m3k

    m3k Member

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    yeah im not alone when believing the springing back pressure of bowden helps. when printing slow- not when printing fast- hence why pressure advance is a thing, or even before pressure advance, coasting and wipe.
    i think a single sided extruder like a titan will print cleaner than BMG in a direct drive configuration. without a doubt not only have i seen it first hand but that youtube video and his research illustrates it quite clearly.
    also i was aware of klipper developing input shaper before it was on git, as resonance_compensation, in fact i was aware of duets attempts at resonance compensation. and even before that the early implementation of sinusoidal based acceleration etc Ive contributed and monitored firmware development closely. but my past nor my credentials have nothing to do with my argument. and if we could argue intellectually id appreciate that.

    but were not talking about even printing fast enough to excite resonance- were talking about laying layers down in a repeatable nature for the cleanest looking layering.
    regardless of the emotions/backlash its stirred up I'm still glad I shared my opinions/findings.

    "Properly aligned BMG idlers do not produce these artifacts, the _world_ would have noticed before now if they did."
    https://github.com/prusa3d/Prusa-Firmware/issues/602

    issue 602 The world has noticed it.

    i wonder if moving to single sided extruders would fix the issues illustrated here:
    https://github.com/VoronDesign/Voro...qVNUISrkx-awYMTf_rIOn29-SwRnGKyk0V4EqWIjYchBk
    I think they're starting to figure out why too
    if you look at the photos they share- especially when printing a uniform shape- you can see the diagonal inconsistent extrusion as illustrated in the youtube video i linked earlier.
     
    Last edited: Aug 12, 2021
  5. Chamelion

    Chamelion Member

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    Both of our prusas were exactly like that... throwing hemeras on them solved it.
     
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  6. m3k

    m3k Member

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    i have heard the same thing from a mate of mine who runs 20+* i3mk3s that the hermera eliminates that issue aswell- its likely either the firm idler gap from the metal construction and/or the tooth profile of the gears probably are the reason why the hermera is better than bondtech gears

    its just that almost all the voron extruder designs i see use bondtech or clone style, granted if thats the only reason im seeing ender3's print 'better' (smoother flat surfaces) than vorons, and the non-stiff X/Y gantry is a non issue- im literally buying a couple formbot kits to go besides my reworked zortrax m300 because i could use more enclosed printers. and personally ive been a fan of belt-z printers ever since the up plus2 was released- infact ive built some Core X-Z printers in cad for fun but never really committed to it

    lol if issue 602 wasn't common then why make this t-shirt...
    https://pbs.twimg.com/media/DiVvh6HVAAAU0sB?format=jpg&name=medium
     
    Last edited: Aug 12, 2021
  7. m3k

    m3k Member

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    before I hijacked this thread. with my abrasive and admittedly poorly worded comment - :wired: awk, welcome lurkers- sorry if your first post was a result of frustration towards my comments! :p


    This sounds a bit like heat creep (when the cold side of the hotend does not wick away/ receive enough cooling- This will cause the filament to swell in the throat and cause the clog
    some people help eliminate this by adding a bit of thermal paste into the top part of the heat breaks thread- to help it wick heat to the heatsink better- you can also try and increase the size of the cooling fan- if the mounting options are limited- remember you can go from a 40x10 to a 40x20 mm fan for extra airflow! -
    after you've done this- since you have an allmetal hotend you can try seasoning the throat/nozzle by applying a little drip of vegetable oil to the filament as it feeds into the hotend- technically just like a WOK it should make the internal surfaces a little more plasti-phobic .. in theory atleast.. i hear it works
     
    Last edited: Aug 12, 2021
  8. holdennutta

    holdennutta Member

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    Just finished assembling my Prusa i3 mk3s+ kit.
    Pretty enjoyable process up until the wiring managemen at the end. It’s pretty disgusting. Electronics box seems smaller than it should be.

    Hopefully tomorrow I’ll be able to do the power on and testing.

    Edit: Fixed some words that were entirely wrong somehow.
     
    Last edited: Aug 12, 2021
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  9. Sunder

    Sunder Member

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    Well, finally got around to giving it another shot, and nothing worthwhile:

    upload_2021-8-12_16-6-38.png

    It looks like I might still have a few other issues to fix - For example, none of the layers look that great left to right adhesion wise. I raised the temps and increased the flow rate to try to fix that, and that may actually be the cause of the issue. Could be under-extruding instead?

    Used these settings to change the retract distance:

    upload_2021-8-12_16-6-56.png

    Might go back one step and try to do another temp tower. Other suggestions?
     
  10. Chamelion

    Chamelion Member

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    So yep.. going with the magic studios voron 2.4 kit. Seems to be fairly decent. Will be a $2200-$2500 build. Pretty good considering a prusa is 2/3 of that.
     
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  11. Butcher9_9

    Butcher9_9 Member

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    Did you try drying the filament? Wet filament can cause issues with first layer adhesion as well which would then make you change settings that otherwise might not have otherwise changed.


    FYI, That image looks like a bridging test rather than a stringing one.
     
  12. Butcher9_9

    Butcher9_9 Member

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    At least that way you will get quality parts, if you are building a baller printer might as well be full baller.

    Going premade cables ect? Making your own cables gets old pretty fast.
     
  13. Chamelion

    Chamelion Member

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    Yeah cables come in the kit. We're basically taking every 'premium' option they have available, inclusive of PTFE cables, rather than silicone.
     
  14. Sunder

    Sunder Member

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    Thanks for comenting. The filament has been sitting in a dry box at 10% humidity for a month now. I would have thought that was long enough, but if this keeps up, I might just get another roll.

    The tower was generated using the in-built Cura tools, I'm pretty sure the shape was retraction tower and I applied the retraction script to it.

    Printing a temp tower, I noticed that the extruder occasionally slip, which would account for the under extrusion. I think I have fixed that now and trying again.

    I have also turned up the fans from 10% to 100% as I read that having it too low on bridges can cause sagging and what appears to be stringing but isn't. So many dimensions to check!

    Thanks for the advice though. I'll keep trying, but certainly feed back at every attempt would be appreciated.

    On a semi-related note, I have been considering a few options:

    1) upgrading the extruder and hot end. Pros- less than $100, might make some improvement in print quality. Cons, you can only polish a turd so much - it's been a good hobby printer, especially for my first projects which were essentially rapid prototyping to get drawings for CNC machining, but now I've moved on to things that I actually want to keep and work like custom fit hinges, latches, etc.

    2) Upgrade to a better midrange FDM. Maybe something dual head and enclosed, around $1k to 1.5k? Pros - it comes at a better quality without modding it. Cons, it's a fair chunk of cash which might not be that much better.

    3) Keep the I3 Mega for big coarse stuff, and get a low range SLA printer for smaller parts that need to move. Pros, it's cheaper than a full upgrade, but I can do precision prints FDMs could only dream about. Cons, I would need to join pieces, and my wife will kill me if I take up any more room in the house.

    Thoughts?
     
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  15. m3k

    m3k Member

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    Hi sunder, yea thats dry enough forsure!

    The any cubic i3 mega is a capable printer- a guy i knew printed a whole rc snowmobile on the mega
    https://www.reddit.com/r/3Dprinting/comments/k7sgbw/110_scale_rc_snowmobile_i_made_last_winter/

    before you start throwing money at the hobby- i really suggest watching as-many quality youtube channels to help improve your print quality and learn
    because even if you get a new printer- chances are when things go wrong you will need to learn the same lessons again anyway.
    if you want a nice shortcut maybe there is a good profile for your fav slicer that somebody is sharing with the community after tuning- and you can use that as your starting point
    its likely no matter what printer you get- you may experiment with different filament cooling methods and hotends and nozzles etc. and they all have their own perks
    some nozzles have a special coating that repels plastic and tends to make stringing less apparent- especially for plastics like PETG that is notoriously a bit stringy and can stick to nozzles
    even slice engineering release a coating you can put on your nozzle to stop plastic from accumulating on your nozzle and block


    The only mods id suggest (its not necessary) to do on a cheaper printer is swap the heatbreak to a quality either bimetalic or titanium all metal heat-break and compatible nozzle- because teflon liners will degrade even when printing PLA over time ( a long time mind you depending on how hot you print), its not ideal. and a quality heatbreak will be the difference between oozing and clogging or not.

    swapping the extruder to something like a hermera will net you some quality- but then as you said you'll be getting into the territory of maybe u can put money aside for a different printer.

    here is a video that helps for bridging for example:


    I often suggest the i3mk3s to beginners because it makes the learning curve really gradual and its got alot of good features to stop users from breaking it :p - crash detection- quality filament runout sensors- Great LCD prompts - great usermanual & documentation and finally great accessible and helpful community.
     
    Last edited: Aug 12, 2021
  16. garfield2k

    garfield2k Member

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    i agree with m3k, dont be spending money just yet. maybe start calibrating from the start again. go on teachingtech and go thru the calibration steps to see if that helps, shouldnt take too long but gives you the baseline to start any additional troubleshooting.
     
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  17. m3k

    m3k Member

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    if u ever land on design prototype tests channel- just set the play speed to 2x and get ready to skip every time he cries about patents being ripped off or teaching tech stealing his video ideas - shade aside he has some decent content :p.

    also your extruder slipping might be from many things- and honestly its been covered on countless videos but here are some suggestions:

    -perhaps printing too cool, ( dont print too hot it can degrade the Teflon liner :p )
    -your Teflon liner might be deformed and making the filament path slow,
    -your spool holder might not roll smoothly enough- especially on a full spool,
    -your nozzle might have a semi-clog,
    -you're simply asking for too much speed,
    -your stepper drivers are set to too low current ( last case scenario- and risky because if you run the extruder motor too hot it can deform filament and or generally run too hot)
    - and much more- there are a lot of variables here- you can diagnose this yourself by susing out the filament path!

    ALSO- dont be afraid to try new slicers!

    a really cool new slicer is kiri moto! https://grid.space/kiri/
    it even has a profile for your mega
     
    Last edited: Aug 12, 2021
  18. OP
    OP
    Spanos

    Spanos Member

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    Yeah, you want to find out how far the head can travel before it oozes. I assume you know that oozing is just melted filament falling out of the nozzle in an uncontrolled manner? It's a combination of different settings and varies with different filaments.

    So, you want a test that let's you find out how far your head can move without oozing. So that means you'll need to print objects that vary in distance. For my own test, I printed a basic cube and placed them on the bed and then specified where the head starts each layer. Then, i can find out how far the head can shift before it starts to ooze.

    I often change my print settings based on what I'm printing. I've written down the settings based on the defects I can expect in a print. Then change them accordingly based on the print that I'm making.

    Lots of learning to be done :)
     
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  19. Sunder

    Sunder Member

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    Thanks for the feedback guys.

    I did most of this when I first got the printer a couple years ago. But I think between tweaking for specific use cases as well as trying to compensate for damp filament and cold weather meant my settings were way out of whack. With patience, it is usually easy to fix something when only one or two settings are out of alignment. But when multiple are, and they can be either exacerbating or compensating, it can be really complex to lock one down and eliminate root causes. So appreciate the feedback.

    But on the bright side, it seems just adjusting the fan speed has helped substantially - Still some way to go, but this is starting to yield results:

    upload_2021-8-12_21-32-20.png

    That's a temp tower, 230 to 260. I normally print PETG at 255, and I think that vindicates it. Some VERY minor stringing at that level that doesn't exist in 250, but it bringing it down one level looks like it's getting pretty close to some bad bonding at 245.

    However, the whole tower does feel a little brittle compared to normal. If I recall correctly, I turned cooling right down because of that, and an article that said you don't really need print cooling on PETG. So I might try another temp tower with exact same settings, but 50% fan, and see if that helps. Then probably another retraction tower... By that time, I'll probably have enough left for one small print, and I'll have to get another roll and start again :p (Actually 3D Fillies have been pretty consistent, so mostly joking!)

    Oh, and with regards to the extruder slipping, I meant the gear drive. It's odd, the spindle is keyed, but the gear on it is not. It's tightened on using a hex head nut, and it had come somewhat loose. I tightened it, and seems to have solved the problem.

    Appreciate the support gents.
     
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  20. m3k

    m3k Member

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    im glad ur figuring everything out! :D

    dont be afraid to use a bit of thread locker on the grubscrew!

    ur printing 260c with a teflon lined hotend?
    id suggest sticking to capricorn tubing because it has the highest melting temp- but even then its not very health to huff
    https://www.captubes.com/safety.html
    Capricorn rkns their tubing wont deform at these higher temps- but the moment i go past 210c i try to swap to allmetal

    also the bottom of that temp tower looks very good- Id be happy with that up to three tiers up- you've done a really good job diagnosing this issue- and dont be fooled- this is something you will encounter on any price and tier 3d printer- dialing in your settings for your specific filament is a pain that everyone deals with- unless youve got a prusa and your using prusament profiles and the like :p

    I often print pet-g around 255- also, however this video helps understand its characteristics better

    apparently dasfilament petg has the best interlayer bonding at 220c!

    i use 30% fanspeed personally its the bare minimum to get quality overhangs for my particular fan setup

     
    Last edited: Aug 12, 2021
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