There seems to be a lot of confusion on using an Ender 3 3D printer about, and the same questions keep getting asked over and over. The printer is cheap so everyone and their grandmother seems to be buying it, which is great, but oh the questions of bed levelling!
The very first thing to do is build the bugger correctly. The instructions are nothing but garbage, I didn’t even open mine. Lay all the bits out on a large table, sit down with this video by Tomb of 3d Printed Horrors, get a beer and build it as they do. Allow a couple of hours to do it correctly, I can’t stress this enough, build it once, build it right. If the thing isn’t square from the outset then you’ll just introduce more issues as you try and upgrade/improve the print quality of it.
Once you’ve got it constructed, now you need to level the bed correctly, follow these steps for the first time.
- Turn off the printer.
- Unscrew the Z end stop switch, the thing on the bottom of the left vertical gantry, there’s two allen key nuts, slacken them off and slide it down. Leave it loose!
- Tighten fully each corner bed levelling wheel so the springs are fully compressed, look at them so they look tight.
- Turn each bed levelling wheel back two full turns each, no more. Use a white pen to put a dot on each wheel so you’ve a reference point for rotating them.
- Gently move the nozzle so it sits above the middle of the bed. Don’t move it too quickly as you’ll reverse power the motherboard as stepper motors also work as generators. Don’t fry your electronics before you’ve built something yet!
- Manually twist the Z lead screw so the nozzle goes down to the bed and gently touches it.
- Move the Z endstop switch that you loosened earlier up the vertical gantry until the microswitch just clicks against the Z gantry. Now tighten those two screws. Sometimes you might have to cut the tab off the z switch plate as in the above video, I did mine.
- Gently twist the Z lead screw so the nozzle moves up away from the bed, an inch or so is fine.
Anytime you make adjustments to the bed, like replacing it with glass, or swapping from glass to buildtak etc, you need to readjust the Z level switch, so do above again.
Now it’s time to level the bed with paper:
- Turn on the printer.
- Click through the prepare menu for Auto Home and wait for it to complete its homing.
- Now in the menu click Disable Stepper Motors. By disabling them it means you can move the gantries as required.
- Slide a piece of normal paper under the nozzle in its forward left position. The paper needs to make a scratching noise against the nozzle as it slides underneath. If it doesn’t, then adjust the wheel on that corner until you can get the paper underneath, and it scratches.
- Gently pull the bed toward you so the nozzle is in the rear left corner, do the same with the paper, adjust the wheel as necessary.
- Slide nozzle along the Y gantry to the right, do the paper trick in the rear right corner, adjust the wheel as necessary, you want scratchy paper sounds.
- Push the bed away from you so the nozzle sits in the fore right corner, do the paper trick again so you get scratchy sound.
- Now do 4-7 again, perhaps twice more! The problem with having four corner adjustments is you don’t get a level plane easily, a three way adjustment you would. So each time you adjust one wheel, you need to check the others generally.
The bed should now be level, go into the menu and select the dog from your SD card and let it print!