2
$\begingroup$

My Ender 3 has started having problems printing. It does not seem to be getting enough power. I have cleaned the hot end, checked the PTFE tube seat, replaced nozzles.

It is missing steps on the extruder motor. I increased vref for the E-axis first to 0.9, then 1.0, then 1.2. The extruder works properly, but now it is missing steps on the X-axis.

$\endgroup$
2
  • $\begingroup$ How have you diagnosed that it is a "power problem"? $\endgroup$ Jun 17, 2021 at 6:29
  • $\begingroup$ What makes you think increasing e-steps will improve step skipping? What filament are you using, what hot end temp? Is this first layer only, later layers only, or all of them? $\endgroup$
    – Zeiss Ikon
    Jun 17, 2021 at 12:33

1 Answer 1

4
$\begingroup$

This is a common issue, there are a number of problems that could cause an extruder motor on the Ender 3 to skip steps besides the stepper needing an increase in current. If the extruder motor is missing steps--which usually results in a periodic clicking noise--this is likely due to one of the following common problems.

  1. Nozzle is too close to bed
  2. Print temperature is too low for a particular filament
  3. Nozzle clog
  4. Filament "clog" in the hot-end gap between Bowden tubing and nozzle
  5. Extruder stepper motor is undercurrent

To quickly and effectively diagnose each of the problems above:

[1, 2]. Move the nozzle away from the bed ~(+20 mm Z) so that the nozzle is a good distance away and extrude 25 mm of filament. If the clicking stops and the extruder stepper is working properly, you know that the nozzle is too close to the bed and you should re-level the bed. If the clicking/missing steps persist, you should increase the temperature of the hotend to the upper bound of the recommended temperature for the filament (ie. for Hatchbox PLA temp. range on label is: 180 °C - 210 °C). Extrude 25 mm of filament again and observe extruder motor as above.

[3, 4]. If the extruder motor is still missing steps, you are going to need to inspect the nozzle and hotend assembly in greater depth. You should remove the nozzle like this. See if you can clean it out or replace it if it is clogged (might be best to replace it if you have extra nozzles either way). Check to see if this fixes the extruder motor problem by extruding filament with the hotend sufficiently far away from the bed as in steps (1), (2) above. If this still doesn't solve the issue, the most likely problem is (4) a gap of space in the hotend between the nozzle and Bowden tube getting filled with molten plastic. To fix this, remove the nozzle and disconnect the PTFE tubing. Slide the end of the PTFE tubing through the hot end and wipe off the end of the PTFE tubing with a paper towel to clear out all of the gunk before you pull it back through the hotend. Check the last few mm of the tubing for any gunk and if necessary cut the last few mm of the tubing (ideally using tube cutters) or replace the tube with Capricorn PTFE tubing. Tighten the nozzle to "finger-tight" ie. the tightest you can before you must use the wrench and spanner, then loosen the nozzle ONE FULL REVOLUTION. Now push the Bowden tubing down very hard so that is flush up against the nozzle. Now, properly re-tighten the nozzle all the way. This ensures there is a tight fit between the nozzle and the end of the tubing that prevents this gap from arising. If this is the issue, you may also want to look into replacing the Bowden tube coupler at the top of the hot-end assembly (the stock ones that come with the Ender 3 are cheap and often the root of issues). This entire problem and fix is extensively covered here

[5] The issue the OP suggested is not the definite cause of this issue and as such, it should be checked last as it is a "catch-all" solution which is less likely than 1-4. I would only increase the extruder stepper current as a last resort (assuming your Ender 3 has already been properly calibrated and functioning in the past). As the OP suggested, you would increase the current for the extruder stepper by using the vref potentiometer on the main control board like this.

The list above contains common/likely potential issues and best practices to troubleshoot them, not an exhaustive manual of possible reasons why the extruder motor is skipping steps or under-extrusion is occurring.

$\endgroup$
1
  • 1
    $\begingroup$ Nice first answer, John! Please be sure to take the tour and read over the FAQ -- it's good for a little rep even if it's (seemingly) stuff you already know. $\endgroup$
    – Zeiss Ikon
    Jun 17, 2021 at 13:10

You must log in to answer this question.

Not the answer you're looking for? Browse other questions tagged .