Mark's excellent sBitx case was too large for my Ender 3. I split the the top and bottom parts into two pieces that fit the Ender 3 bed. I chose the bottom with the speaker mount.
I printed in PLA with supports and a brim and a bit of glue stick. The left top just fits the Ender bed as I didn't want to split it through the display. Parts were glued into one piece with cyanoacrylate glue.
I added the washers in 2.5, 3 and 3.5 mm thickness for the encoder shafts. I ended up using the 3.5 mm to stop the encoder board bending when nuts are tightened. You will need two.
73

Creality

Ender 3

No

Yes

Used Brim and glue stick
Full credit to Marks case https://www.thingiverse.com/thing:6445926