Extruder set-up on Ender 3 v2

Hello
While printing with my new printer, the blue extruder wheel jumped off.
Looking at the extruder, I couldn’t replace the wheel until I realised that the brass driving cog had risen up, pushing the wheel off.

The cog has now been reset at a reasonable height (I think), but I had to remove the compression spring to get at the cog’s grub screws.

Now, the extruder isn’t pushing filament through - or is only pushing through intermittently.

Questions: [LIST=1]

  • What height should the cog's teeth be set?
  • How should the compression spring be set? [/LIST] Help TIA
  • I don’t have a 3 V2, but I set my toothed wheel by sight. I push some filament through so it’s close to the wheel and ensure it’s somewhere near the middle of the wheel. It doesn’t need to be exact. Then make sure the grub screws are securely tightened. If the stepper shaft has a flat spot, ensure a grub screw is up against the flat.

    The tension spring is required. I tighted mine until I get even feeding of filament without skipping.

    if this is the default plastic extruder also make sure it isn’t cracked underneath. Mine lasted for about 3 weeks until that happened and it would not extrude any more

    Something like this?
    http://forum.makewithtech.com/forum/3d-printing/11473-i-found-the-hidden-reason-for-bad-prints

    It is the default extruder, I only built the printer this weekend.
    I suspect a problem at the hot-end or nozzle, because I can use the wheel to crank filament along the Bowden tube.

    Let me see if I can help as I have an Ender 3 V2.

    The extruder wheel/dial has no impact on your 3d prints. Its only purpose is to make it easier to load and unload filament. You turn the wheel to the left to push the filament into the Bowden tube in the same way the stepper motor would push the filament. You turn it to the right to pull the filament out of the Bowden tube.

    Your printer will work just fine with this completely off. I find it is much faster to squeeze the lever that releases the pressure between the gear and the idler and then just push the filament in or pull it out.

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    This is a picture of the extruder with the wheel removed. It just lifts on and off.

    The lever on the left, which has a pivot point on the bottom left and pushes on the spring on the top, will move the idler wheel (with the bolt in it) away from the feed gear when pressed. Your filament sits between the gear and the idler. With no filament in the extruder, the spring should be tight enough so the gear just touches the idler.

    The gear teeth should be centered on the idler so the filament will run between them smoothly.

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    This picture has the blue wheel on top of the stepper motor drive shaft. I generally lift it off when initially loading filament so I can see that the filament is sitting properly between the gear and the idler and to make it easier to feed the filament into the Bowden tube.

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    As the other participants in the forum have mentioned you want enough pressure on the filament so the teeth of the extruder gear to hold it but not so much that it eats up the filament.

    Thanks for the post @Irv_Shapiro. Good info. Do you know if the non-pro version of the V2 comes with a metal or plastic extruder?

    Thanks @irvshapiro1 , apart from having my spring screw tighter and some Capricorn blue tubing, that is what my extruder looks like.

    @Ender5r , it is a non-pro v2 - not sure that a V2 Pro is available over here.
    (Off topic, Creality Official are having a sale on their UK web-site at the moment, don’t know about elsewhere, or how often that runs).

    @Ender5r I have a stock v2 ordered directly from Creality China when they first came out. I believe the Ender 3 Pro is the old V1 Ender 3 with some upgraded components.

    My primary complaint with the V2 is the new display. It is very pretty but does not have an area to display M117 messages which Octoprint uses extensively.

    @irvshapiro1 I put an Ender 3 Pro display on my Ender v2 and I like it better that the fancy color one that came with my V2. The one I bought came with the bracket too.

    Having to heat the nozzle before being able to remove it is an indication that there was filament still in the nozzle. It could also indicate that some filament had gotten into the threads, something that’s confirmed by your photos.

    Questions: [LIST=1]

  • when you tightened the nozzle into the heater block, was it heated?
  • did you leave the nozzle loose by 1 turn, then push the Bowden tube down firmly to ensure it was all the way down, then tighten the nozzle in, all while having the nozzle heated? [/LIST] I recommend you have a look at this video: [U]https://www.youtube.com/watch?v=7tCxO17XZtw[/U] for a nice mod for Creality printer hotends.
  • [LIST=1]

  • The nozzle was fitted as supplied until I removed it for those photos (no idea what they did at the factory).
    Should I heat the nozzle when I put it back?  I hadn't heard that before.
    
    When removing it, I only experimented with heating 'cause a) the nut was a huge effort to turn without heat, and b) I thought aluminium has a larger coefficient of expansion than brass, so heating could make the nozzle easier to turn.
    
  • When I first replaced the Bowden, no it wasn't heated, indeed I'd never switched the printer on. I'd found and followed a video recommending that the Bowden nut be backed off one turn, before pushing the tube home and tightening the nut. [/LIST] Thanks for the heads-up about the Creality hotend mod. Still on my first PLA reel, so that Filament Friday mod will have to wait until I buy some PTFE.
  • re: [LIST=1]

  • yes, heat the nozzle to printing temp. Not sure which aluminum you're talking about. The aluminum in the heat sink shouldn't come into the picture at all.
  • if you re-read what I posted you'll see that I said to leave the [I]nozzle[/I] unscrewed by 1 turn, not the Bowden coupler. You heat the nozzle up (with the loosened nozzle) push the Bowden tube down, making sure it's bottomed in the heater block, then tighted the nozzle up (not too tight, just firm). [/LIST] When you get more Bowden tubing, be sure to get Capricorn (watch out for knockoffs).

    Generally speaking, never trust hobby class printers to be set up correctly when you 1st get them. Even if they were set up perfectly at the factory (highly unlikely) they traveled all the way from China. Along the way they get handled a lot, so things get out of whack.

  • From you photo it would appear that 212C or 213C is the best. l also see some significant stringing on the left and right. This would suggest your retraction distance and speed need adjusting. Be aware, these 2 factors are often filament specific. They also, normally, differ considerably between Bowden and direct drive systems.

    Here’s a less than 5 minute video on a commonly used test for stringing – the Twin Towers Stringing Test: [U]Retraction Calibration - YouTube

    Thank-you for suggesting I look at my retraction settings - that took a bit of time using retraction towers, but the photo shows is what I have so far.

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    Photo annotated for clarity.

    In this case, retraction distance is most significant, while changes to retraction speed showing little difference.

    That certainly looks better. The stringing tower on the right looks pretty good, although it is a little far away to see in detail. Your choice of 2.5mm retraction @ 40mm/s seems quite reasonable.

    I forgot to mention that the 2.5mm retraction is a little bit surprising in that it’s a value that’s usually used for direct drive extruders. I’m wondering if it’s because the extruders are pretty close to the hotend, sitting on the bar just above the hotend. In any case, the test prints seem to back up your choice.

    I don’t know, but a few of changes to the printer that might have helped.

    The Bowden is Capricorn blue, and a label reel holds the tube to give a reasonable filament feed run:
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    The filament reel stands on a set of spool holders that wouldn’t hurt either, but I doubt that affects retraction.

    The label reel idea was pinched from Irv, after I had an issue with cables interfering with print bed movement.

    p.s. Sorry about all the unreadable black here; printer, filament and table.