Bed leveling on the new Creality Ender 3 Pro

One issue I repressed from earlier 3D printers I’ve owned was the joy of bed leveling. This process always seems to be part art and part science – involving numerous iterations. Usually when I get it done, the bed leveling holds true for a long time, so I’d forgotten all the frustration.

The following is the process I used and some of the modifications made for the Creality Ender 3 Pro. Much of this process was based on materials I’d found on the various support websites and forums, mixed with a little reality. Forums and sites on a machine are a key buying criterion for any purchase in my mind. If there are not information from others who have used the device, you’ll be out there blazing a trail instead of getting done what you were trying to do.

I am not saying this is a perfect approach, but it is the one I ended up with. The one great feature about the Ender 3, I didn’t have on any of my previous printers, is an actual console on the front where I can control the the 3D printer and even print g-code from the SD drive.

Setting the bed height and leveling the bed

A summary of the following step:

First we will adjust the bed spring tension. Set the z end stop height, and level the bed using a sheet of paper.

Figure 1

1. Loosen and lower or remove the Z end stop. Shown in the figure 1 at bottom of left vertical rail support/extrusion.
2. Working the knobs in pairs, front and back, tighten the bed down until the springs are fully compressed.
3. Back of the knobs 3 to 4 turns on all 4 corners. Again, working in pairs. Figure 2 Note the level of spring tension.
4. Disable the stepper motors using the control on the printer under Prepare -> Disable Steppers
5. Manually move the hot end up above the bed in front left corner, using the z lead screw (the long-threaded rod that moves the extruder up and down) manually move the extruder that sits on the x gantry up 10 mm or so.
6. Place a sheet of normal letter paper stock between the extruder and the printer bed.
7. Slowly lower the x gantry until a piece of paper moving back and forth drags against the nozzle. If the paper can’t move then you can’t print layer 1. If it moves to easily, the filament will not stick to the bed.
8. Place the Z end stop switch on rail and move it up until you hear the switch “click”. If the little plastic nub at the end of the Z stop mount is in the way, remove it with a pair of diagonal cutters. I had to do this on mine.
9. Tighten the Z end stop at this position. Ensure that the rectangular ‘nuts’ are aligned to fit under the sides of the rail and are not just in the slot.
10. Activate the Prepare -> Auto Home option on the printer screen.

Figure 2

Bed stabilization modification

Goal:  Stabilize the screws that cause bed level to shift, also secure the screws, so they do not spin when attempting to tighten adjustment knobs. This should stop the bed from leaning or tipping.

Process: Unscrew and take the bed leveling knobs off, lift bed up and remove the springs. Add a 4 mm jam nuts (thin hex nuts) to each of the screws to lock the screws to the bed surface. Note: Do not stress the heater wires as you flip over the bed to work on it.

You will need to stop screw from rotating with a pliers as you tighten nut against back of bed surface. Shown in Figure 3.

Figure 3

Holding bed level, test fit the bed into the Y mounting plate making sure screws move freely through that plate. If not, slightly enlarge holes, or loosen and shift screws so they do not hang up when moving up and down. Remount the bed to the machine.

Y axis trolley eccentric wheel adjustment

Issue: Bed rollers not properly tensioned against the v groove

Symptoms:

Too Loose: Bed has excessive rock or wobble when gently rocking across X axis, bed leveling does not repeat. Layer lines have waves in them.

Too Tight: Stepper straining, a pronounced flat spot develops on wheels when left unused for a while. Type 1 bed skewed away from square in Y axis.

Example of eccentric nut to understand how they function

This nut has an off-center hole, allowing the controlled movement (left side in figure 4).

Figure 4

Tip machine up or lay on side shown in figure 5. Use eccentric nuts to adjust the rollers against the Y axis bar. Loosen both eccentric nut wheels. Rotate first nut until it just stops excessive movement. Tightening the second eccentric nut until there is some resistance to turning rubber wheel while holding carriage in place. Once adjusted properly a moderate pressure applied to the bed corner should only see 1 to 2 mm of deflection. Do not over tighten!!

Figure 5