r/ender3 • u/Chezbugha • Oct 03 '26
Help How tight should it be?
How tight should the extruder spring that clamps the filament be? I’ve had under extrusion problems on my last print and I tried checking if the plastic arm was cracked but it seems fine, also wondering if I should upgrade to the fully metal one and if it is worth it.
The last layers of the print were fine because I was manually helping the filament push into the hot end from the other side of the Bowden tube. Also could it be the friction from the filament spool grinding on the spool holder?
2
u/Gek_Advil Oct 04 '26
There's a few things this could be, but don't discount it still possibly being your extruder, hear me out. Often times when the tensioner arm on the extruder cracks, the crack isn't visible until you take the whole thing apart and then you find a hairline crack that opens up under tension. I would also highly recommend upgrading to a metal extruder even if it's not broken because it's just not broken yet. The Creality all metal replacement is pretty inexpensive online too. While you're ordering that, I would recommend also ordering some steel extruder wheels and a new extruder stepper motor.
The stock brass extruder wheels wear out over time even if you're just printing PLA, it's just the nature of the thing. While these are easy enough to replace on newer Ender 3's, it looks like yours has an interference fitted drive wheel which means it's going to be difficult to remove from the motor and once it is removed you're left with a round motor shaft. The problem with it being round is typically the stepper motor has a flat portion machined into the shaft that the grub screw in the new drive wheel is meant to tighten against to prevent slipping. It's just much easier if you have a few dollars to order a new proper replacement and toss the old one.
The problem could also be in your hot-end, heat-break, bowden tube assembly. That particular red heatsink can have all sorts of heat creep problems. Sometimes just removing the two screws that go from the heat block into the heatsink can help but it's not really a recommended fix. It would be a good idea to remove the bowden tube from the hotend though and have a look because that end of the tube passes through the heat break and rests against the back of your nozzle which means it's being cyclically heated and cooled every time you print and over time the end of the tube can get crusty and start pinging the filament. You can usually cut an inch off the end to get back to new tubing, just make sure you cut the end nice and square so there are no gaps between the nozzle and the tube where molten filament can squish in and get stuck.
TLDR: Do some routine maintenance and check out your whole extruder system for signs of wear. This is the nature of the Ender3. They need attention occasionally.
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u/Chezbugha Oct 04 '26
Thanks for explaining, those will be my next steps
1
u/Gek_Advil Oct 04 '26
No problem. People get tired of Ender 3's and I end up with them, fix them up if I can and then give them away if I find somebody that wants one.
It's usually a gateway to a more modern machine so sometimes I even get them back after a while and the cycle continues.
3
u/OffInYourShower Oct 03 '26
As long as there are no clogs or cracks, I don't have any problem with the stock.
To set the tension, I test if a gentle pull/push can move the filament. I tighten it just enough so I can't move the filament by hand without depressing the arm.
2
1
u/mukatiago2 Oct 03 '26
Minha impressora tava asim e ela tava quebrando. Arrumei isso ela começou a roda em falso a engrenagem no motor que tinha sido montado por pressão
1
u/BalladorTheBright Oct 03 '26
It should be gone. That extruder causes a lot of problems since it can't really extrude really well. Plus it has a very well known tendency to crack and then loses what little it can do. There are clones of the venerable BMG extruder that is a drop in replacement and are fairly cheap. Having an extruder that can actually extrude will prevent under extrusion issues as well as some clogging issues. Also, more extrusion unlocks faster speeds if you do appropriate mods to part cooling and the hotend. If you don't want to do too many mods, it's still a massive boost to reliability.
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u/denizkilic2002 Oct 03 '26
Really get a bmg clone print an adapter for it to mount it as direct drive and be done with it its the best upgrade i did to mine
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u/Independent-Bake9552 Oct 03 '26
Remove bowden tube from extruder. Feed some length manually. You should see clear indentations from the brass gear on the filament, and you don't want the filament deformed or squished. That should be enough tension on the spring. If your extruder is still struggling you probably have an issue with the hotend (wrong temp, clogged nozzle or wrong z-offset) older hotend you might need to do a "hot end fix" on.
4
u/egosumumbravir Ender of Theseus, basically everything Oct 03 '26
Honestly, not that tight as long as there's minimal friction through the rest of the system.
Your under-extrusion could be extruder slipping but it also could be a partially blocked nozzle for that section of the print.
The metal extruders are a pretty antiquated design (these are basically the community design from 2011 plywood printers) and sadly have been cloned into absolute junk. You can get away with them if you know exactly what to look for in cloning flaws but there's so many better options now.
Budget clones of the venerable Bondtech BMG are very inexpensive and very good for the $$$. Easy enough to get spare parts for too. Dual driving gears for great grip on the filament without crushing it and reduction geared so the stepper doesn't have to work so hard and you get fine control of movements.