The most valuable upgrade for Ender 3 is the installation of the motor dampers!
Just believe me. I have printed a lot of mods and most of them are good looking but add almost nothing to the actual printers characteristics. That is not true for the dampers! You will experience shocking difference in the quietness and a good improvement in ringing-free surfaces at the same print speed.
Let's get through it step by step:
Extruder damper - the easiest to install, no need for extra printed parts, just find 2 small M3 bolts (you are going to need a pair for each damper). This one is actually not a must.
X and Y dampers - the most important two. New Ender 3 mostly comes with press-fit pulleys on X and Y so you need to print a few parts. This guy made a working design for it: https://www.thingiverse.com/thing:3245255 https://www.thingiverse.com/thing:3271077
Z-axis damper support: the one I designed. Z motor is not the noisiest one, but the damper also negates small jams in vertical rod rotations which can influence z shifts because the engine has less torque when it positions between steps. With the damper installed you should be able to slide the printer's head assembly up and down with one hand on full z-rod range without holding the printer by other hand, all the rod screws beign tightened.
You will need these to install the z-damper:
1x printed detail from this page;
2x short M3 bolts;
2x M4 bolts like the ones that screw the original z-motor holder to the vertical frame, but shorter and with t-nuts. I don't recommend vandalising original bolts because if something goes wrong you will be stuck and can't get back. As for the t-nuts you should have some left from the printer's assembly or you can print it here: https://www.thingiverse.com/thing:3366563 or just grab a file like I did and quickly make a few from M4 collar nuts;
1x M5 bolt with t-nut to fix the part to the bottom frame (M4 also will do);
1x nema17 damper. You can buy these in large internet store for $1-2. I would prefer this: https://www.banggood.com/Shock-Absorber-Stepper-Vibration-Damper-for-Nema17-Stepper-Motor-p-1188070.html?rmmds=detail-left-hotproducts__2&HotRecToken=ChQxMDA1Mjg0NTYwMDkxOTQzNDQyNRACGgJJViICUEQoAA&cur_warehouse=CN with the large inner diameter but his one: https://www.banggood.com/Shock-Absorber-Stepper-Vibration-Damper-for-Nema17-Stepper-Motor-p-1064910.html?cur_warehouse=CN also will do for the Z, Y and E axis.
It would even do for X-axis too after some jigsaw work, but that is not the topic of this post.
A few important notes:
- align the detail on the vertical frame horizontally. Unlike the original detail it won't align itself;
- when re-installing the rod and the sleeve, make sure the rod does not touch the engine spindle! the rod and the spindle should go into the sleeve just to be firmly caught with the sleeve screw and should not meet inside it. Leave at least 4-5 mm between (see the last picture)
- this should be printed with the outer side down like on pictures 3, 4
- you can use the back of the printed part to organise the cables.
- you don't really need the infill, but i would set 3 lines shell for good stiffness. If you are using cura 3.6.0 please remember to set the infill pattern gyroid even if it is set to 0% because it's the only way to get the proper ironing. It's cura's bug.
You will need some supports. Removes easy, just make sure you left 0.16mm vertical and 0.8mm horizontal space between the support and the model in your slicer.