3D Printer Makes a Loud 'Thudding' noise and then Layer Shifts

[Schmordan 4]

I'm printing with an Ender 3 and when printing, after about 40 minutes, it starts to make a thudding noise and layer shifts. I'm suspecting that the thudding noise is from the friction between the nozzle and the print or it's the printer X and Y axis moving really quickly, but I'm not sure. I'm a bit new to 3D printing, but I've printed things way bigger than this and it works. I also kinda want to avoid modding or changing any parts on the mother board.

[GregValiant 1,251]

Hello @Schmordan.

My printer is an Ender 3 Pro so it's pretty close to yours.  Banging and clanging can be caused by a couple off things.

First are the belts.  They should "twang like the strings on a bass guitar." so make sure they are adjusted as well as you can.  If a tooth jumps because of a loose belt you will get an immediate layer shift.

Under the Speed settings in Cura are "Enable Accel Control" and "Enable Jerk Control".  You should enabled them and set all the Accel settings to 500 and all the Jerk settings to 8 (those are the Ender 3 defaults).  More capable machines can take much higher accel numbers but on light duty machines like the Enders, low acceleration can keep the printer from beating itself up with harsh stops and starts.  If you think of Jerk as "Minimum Speed around a Corner" you would not be far off.  Once again, lower numbers are less harsh on the equipment.

On each of the trolleys, one of the wheels is adjustable via an eccentric cam built into the mounting bolt.  The adjustable one is the one with the large hex nut shape while the fixed ones are round.  You should just be able to turn any wheel with your fingers.  If they are too loose then machine accuracy will suffer.  Too tight and the machine has to work too hard to move the axes.  Adjust them as well as you can.

Cable management.  Make sure there is no interference with the bed cabling, nor with any other cables.  The axes need full freedom of movement and should not be brought up short because they ran out of leash.  I printed a bracket that mounts on the top cross-brace and my cables hang from it with rubberband "suspenders".

Depending on the shape of the model, you should be able to print up to 75mm/sec with no problem.  On smallish prints the machine will never get up that fast and generally, slower will give a better looking print and often, a more accurate print.

The only "Mods" I've done to my three year old printer is a Micro-Swiss hot end, some decent belt adjusters, and I changed all the fans.  In particular, the layer cooling blower was useless but they were all sleeve bearing models and the ball bearing replacements are a lot quieter.

There should be no reason to fool with the mainboard.

The printer can also hurt itself by ramming into the end stops (over- travel).  That is caused by a combination of the machine settings in Cura (bed size), and the home-offset setting in the printer.

 

 

 

[Schmordan 4]

Thanks for responding! I usually print at 100 mm/sec and have a jerk setting of 30 for each one (but that's just personal preference) and have previously changed the extruder and bed springs. i'll try turning on acceleration control and test on the model again. I've tried most of the things you've mentioned, but not the acceleration control setting.

Edited February 28, 2023 by Schmordan