Further to this I’ve posted an update to bed leveling on this thingy https://www.thingiverse.com/thing:4904173

I've been finding some of the options and processes on the Ender 3 a tad painful.

I decided that a gcode routine was a simple approach for me.

The first one included here is bed levelling
Added 20/2/2020 filament change routines.

These are based on simple gcode commands, and I'm sure there are other ways to achieve this, so comment away and I'll add/include as appropriate.

22/2/2020 - Updated to better automate the bed levelling process with less menu searching.
Also, I have added two files, Change Filament and preheat and Change Filament.

10/7/2021 - added link to new thingy for bed leveling with better instructions and explanation of the process, and it’s made a massive difference to print quality

My bed, even with the tempered glass base plate, still seems to have some mild variations where the edges (0-30mm in) are slightly higher than the centre area of the bed. Which creates the very obvious challenges of getting layer one to stick while not gounding the head on the edges.

Finding a balance between the edge and centre consistently has been what works, setting it up has been painful with the manual commands.

So!

I've taken the standard setup routine from Cura for the Ender 3 and modified it for this purpose.

It does not heat the bed or the hot end.

It works as follows:

1. Load the gcode file on your SD card, and fire up your printer.
2. On your print menu select the print option and select the file you saved.

Your Ender should work through the following in this order.

• Home
• X50 Y50 first location, it should pause but my machine ignores this first one and goes to the next. If yours pauses, awesome. Adjust the bed accordingly and select resume print.
• Next location X50 Y185, it should pause.
• Adjust the bed accordingly and select resume print from your printer menu.
• Next location X185 Y185, it should pause.
• Adjust the bed accordingly and select resume print from your printer menu.
• Next location X185 Y50, it should pause.
• Adjust the bed accordingly and select resume print from your printer menu.
• The next location is the centre X117 Y117, it should pause.
• This is to check how things have worked out so far and to assess if you need to make allowances on the edged for the gap, or lack of gap, here where you print most of the time. Once understood, select resume print from your printer menu.
• Next location X50 Y185, it should pause. (Sometimes mine skips this too...)
• Adjust the bed accordingly and select resume print from your printer menu.

At this point it heads off to home again, in case things got pushed in some way and repeats the process.

If you have made adjustments along the way, you'll have to go around a second time to tweak everything slightly, as frustratingly it all moves.

Once it goes around and comes back to the front left again, X50 Y50, it will then lift the head and present the base plate for you to prep for printing, tape/glue/whatever you need to do.

If you still need to fiddle with the levelling, run the routine again. I've found once it's dialled in, once is usually enough and selecting stop print when I have it tidy is the way out from here. (yes, written for noobs who won't know)

Hopefully, this makes this process significantly simpler for you, as it has done for me.

P.s. Use the updated one in the link above

The Change Filament gcode operates as follows:

Starts heating the hotend to 200 deg
Goes home
Waits while the hotend heats up.
Reverses filament 6mm
Moves to the machine determined load position
Attempts the unload of 400mm (You may need to manually unload at this point, I haven't managed to get it to work properly) If it decided to extrude (print) 400mm instead of unloading, switch off and comment out the U400 or change to U-400 in the gcode.
manually load the filament to the hotend.
Once done press the button to reheat if displayed
Press the button to extrude/load filament. Should extrude 20mm of filament.
Select resume print if the colour has come through ok or select extrude more until you're happy it's all good to go.

Once you resume print it will return to home and turn off all fans, heating and steppers.

This is much the same process as the change filament routine, except it starts the heating of the bed to 60 degrees after the hotend is hot while it is doing everything else.

At the end of this routine it doesn't turn anything off, so you can then go and select your print file to print without additional delays with getting back to a pre-heated state.

So be careful with this one if you leave your machine unattended and don't start a new print, you risk machine damage or overheating that could cause a fire!

Any thoughts, comments, ideas on improvements or other things that would be useful, let me know in the comments. Thanks!