Filament grinding

Is there a way to make the gear of the motor closer to the filament so It doesn't grind. The nozzle is 230° but it still grinds the filament.

Comments

  • Stephen ToddStephen Todd Posts: 281🌟 Super Member 🌟
    You could get a replacement gear - the brass ones without the filament groove are normally sharp toothed and available in various tooth counts - can't imagine them slipping

    It's worth checking the mechanics of your existing feeder - people have reported that on their JGAurora printers, the plastic pressure lever cracked, reducing the gear pressure against the filament
  • buklbukl Posts: 8Member
    I had the same issue. I've stretched the spring and added a washer underneath. Now the motor skipps steps before the teeth grind...
    Thanked by 1Samuel Pinches
  • Samuel PinchesSamuel Pinches Posts: 2,597Administrator
    @bukl can you extrude by hand? There could be a source of friction elsewhere preventing smooth extrusion. What print speed?
  • sja454sja454 Posts: 3Member
    My new JGMaker Magic printer printed right out of the box, but the print was not nice (looked like it was skipping areas-looked "stringy".  I uploaded the custom firmware (and was surprised to discover all the new options) hoping this would solve some of those issues.  I tried printing the same object post update, and had similar results.  After watching carefully for a while I discovered that while the extruder gear was turning it wasn't always pushing filament through.  Any ideas on what to look for would be appreciated
  • Samuel PinchesSamuel Pinches Posts: 2,597Administrator
    Check a few things:
    - check that the extruder is providing enough pressure - if you give it some help to grip the gear does the motor have sufficient power to push through?
    - check you're not printing too fast (suggest start 40mm/s)
    - check your extrusion temperature is sufficiently high (210C for PLA)
  • Stephen ToddStephen Todd Posts: 281🌟 Super Member 🌟
    edited April 23
    sja454 - Hot end temperature could be wrong for your filament - too hot and you can get problems with the heat break overheating and pre-softening the filament, or filament baking in the nozzle - too cold, and you cause too much pressure in the nozzle, and the gear teeth slip on the filament

    At this stage I'd do a manual filament "atomic pull", manually push some filament through the nozzle to make sure it isn't blocked, then try printing some heat towers/bridging test pieces from thingiverse at 190c to 210c - maybe also increase print speed

    Some filaments can cause problems - some are utter rubbish



    Post edited by Stephen Todd on
  • giantrobot2001giantrobot2001 Posts: 68Member
    I got this roll of white filament that was an open package on sale.  I thought how old could it really be for half-off? 
    It started skipping and it just wasn't melting right at any temperature.

    After either three small test pieces, the whole kilo went in the trash.  The funny thing was afterwards, when I then put on the new filament reel, I noticed white dust everywhere. Not just the feeder, which was loaded with it, it was all over the printer :D

    At that point I realized I'd actually pay extra for top quality filament.

    Also, if it goes through a filament change, I make sure to cut off a meter right away to get rid of the previous tractor marks.
  • Stephen ToddStephen Todd Posts: 281🌟 Super Member 🌟
    Sometimes a filament you always were happy with can suddenly "change" - you buy a new reel, and it is not the same stuff as before - I buy my filament from Amazon, but now check the latest reviews for any filament that is on a deal price - because you cannot go by old reviews

    I do wonder just how many filament manufacturers there are - a lot of Amazon reviews change from 5 star to 1 star about the same time, making me think that most filaments are just re-brands, and a big filament manufacturer has changed something, making many different brands go bad at the same time
  • giantrobot2001giantrobot2001 Posts: 68Member
    edited April 25
    I have caused pressure in the nozzle by not leveling the table right, and it started grinding at the feed wheel.  I freaked out, and did a quick spool change and leveled the table. 
    When I leveled the table, I realized there was no clearance at all - in fact it was pushing on the tip slightly. That will cause your problem as well as untold other issues which would not be good.  You don't want your extruder tip to be dragging along on that first slice.

    Maybe someone has a better way, but I'm new at this, but already I realize mastering the tip to table clearance is critical.  Seems like 20# white printer paper I take the table to friction - twice to the four corners in order, then table down an additional 1/8 turn - loosening the contact on the four corners (turn nuts toward tighten to loosen), and with the center creating dome that still might be tight, but it's usually right at about exact friction point at center (because of dome), which is where I print. If it's a little tight or loose at center, I do my best to change all four screws the same and check center again.  Since I ran the corners twice - they were all the same, no reason to start over because the center is a tiny bit off.  On the other hand - if you mix up dont get it right at center with that little adjustment, you don't want to keep fussing on the corners with out checking them - at that point start over (in case you cranked one the wrong direction, or just got is wrong)  I read people sometimes people set a corner way too tight because they had their other hand on the table without thinking :o

    and for anyone new who is still trying to figure this out - the tip should be hot or clean so a blob of plastic is not adding to the clearance (of course you'll learn when it starts printing and it's not even sticking it down on the bed)
    Thanked by 1Samuel Pinches
    Post edited by giantrobot2001 on
  • Stephen ToddStephen Todd Posts: 281🌟 Super Member 🌟
    Something that doesn't get mentioned much is that both the bed and nozzle must be at printing temperature before leveling the bed, otherwise the air gap will reduce when things warm up

    Mesh bed leveling is in the custom firmware - a lot of JGAurora printers need it
    Thanked by 1Samuel Pinches
  • @Stephen Todd you said this earlier :  - too hot and you can get problems with the heat break overheating and pre-softening the filament

    can we agree this filament pull in the picture describe what you are saying?
    Too hot for this filament?


    On a side note, the top fan is also noisy on my A5, this could mean it doesn't cool the heat-break enough right? 
    waiting for the replacement by now...

    Just need confirmations here, thanks...
  • Samuel PinchesSamuel Pinches Posts: 2,597Administrator
    That looks like a filament that got too hot looking at that wiggly portion. What material and print settings?
    the fan should definitely have prevented that, but if it is still spinning, maybe there is another cause.
  • Mathieu Grumplefix EvainMathieu Grumplefix Evain Posts: 7Member
    edited May 14
    @Samuel Pinches   It is PLA rated by manufacturer between 190-210deg. This setting was 200deg and ran smoothly in the past (same spool and others),

    I am also waiting for a replacement throat. what else could it be?
    Post edited by Mathieu Grumplefix Evain on
  • Samuel PinchesSamuel Pinches Posts: 2,597Administrator
    If the extruder motor is getting too hot, the filament could be softening a bit in there too? I'm really not sure, definitely perplexing.
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