Ender-3 Controller Case

This is a custom case I designed for my old trusty Ender-3 with a raspberry pi and buck converter, plus two cooling fans. I run my printer “headless” since I use klipper so the design currently does not support the stock LCD display screen. If you would like a design that allows for the stock LCD let me know in the comments.

I've included the STL for just the case with no names or logo's but I've also attached the STEP files if you would like to customize it yourself. You could also add text using PrusaSlicer or Bambu Studio. 

The case is designed to fit a Bigtreetech SKR Mini E3 V3 controller on the left hand side, but the mounting holes are identical to the original board, as well as other drop-in replacement boards so you should be able to use a variety of different controllers. If you have other requirements, feel free to remix my model, or give me a shout and I'll see if I can modify it for you. 

The right hand portion of the case is where you can mount a raspberry pi (designed for model 3B+ but should work with Pi 4. It also has standoffs/mounting holes for a LM2596 DC/DC buck converter which you can use to power your pi directly from the printer's power supply. 

Compatability:

• This was designed for the original ender-3 with the 2040 Y-axis rail, the newer models with the 4040 Y-rail wont work with this mod, however you could remix it if you'd like using the included step file. 
• This is not compatable with the ender-3 stock display. It has no passage for the display cable, and will block the mounting point of the display on the right hand side. (If you would like a modified version that allows for the stock display, send me a message and I will make the necessary modifications. 

Printing Instructions:  It is designed in two parts that should make it printable on just about any 3D printer including an ender-3. You will need a build area of 170 in X and 175-180 in Y to print each half which is pretty common. 

1. You will need to use some supports for the two openings that allow wires to pass from the controller to the raspberry pi and the buck converter. 
2. You can print it with whatever density you feel suitable, I used 3-4 walls and 15% infill. 

Hardware:

• M5x25mm SHCS - 3 bolts + 3 Hex Nuts
• M5x20mm SHCS - 2 bolts + 2 T nuts
• M3x10 to 20mm - 12 bolts to attach lids (you can probably use 8 if you don't have enough)
• M3x8mm - 4 Bolts + 4 T-Nuts to attach upper case lip to 2040 extrusion
• Spare micro-usb (pi 3b+) or USB-C (pi 4) if you want to power your pi via buck converter

Assembly:

1. Once you have printed Contoller Case Bottom L and R, clear out the support structures and all of the holes. The M3 holes should be sized at 2.8mm which will allow you to screw in m3 screws and they will cut their own threads. You may need to use a bit of downforce as you screw them in so its best to do this before starting the next steps of your assembly.
2. Once you've completed step #1, find your M5x25mm bolts and hex nuts (3 each). You will need to press the M5 hex nuts into the hex shaped holes on the middle portion of Case Bottom L. Then position Case_Bottom_L and Case_Bottom_R together so that the chamfers fit snug. Then use the M5x25mm or M5x30mm bolts to fasten the two halves together through the holes and into the hex nuts on Case_Bottom_L. 
3. If you are not using a raspberry Pi you can skip this step, if you are, continue below
   1. If you are using a raspberry pi, you can now install it on the right hand side. You can also attach a 30x30x10 5V fan for cooling the pi to the Case_Lid_R
   2. If you are going to power your pi via a buck-converter and the printer's psu, you will need to run power wires from the psu to the buck converter.
      1. you can then use an old micro-usb cable, strip the wires at one end and solder them to the “out” lines of the buck converter. plug the micro-usb end into your pi.
      2. ***WARNING: MAKE SURE YOU SET THE OUTPUT VOLTAGE ON YOUR BUCK CONVERTER BEFORE APPLYING POWER TO THE PI. If you skip this step and provide more than 5V to the pi you will fry it. ****
4. Next, you will need to remove the M3 button head screws on the top and bottom of your controller case
5. Remove the lid and unscrew the M3 bolts holding the board to the sheet metal case. Don't forget to unplug the cooling fan carefully.
6. Prop the printer up so you can slide the bottom of the sheet metal case downward and out of the machine. 
7. This part can be a bit finnicky. You will need to use 2 M5 T-nuts, and 2 M5x20mm bolts. Push the bolts up through the bottom of the case in the middle until they stick through the slot where the 2040 Y-axis extrusion goes. loosely thread on the 2 t-nuts. Now do the same for the holes on the far right and far left side using M3 T-Nuts and 4 M3x8mm bolts. 
8. Now you should be able to slide the assembled Case_Bottom unit into place, and drop your controller board back in, using the same M3 bolts to fasten it to the new controller case. 
9. Attach the 40x40x10 case cooling fan to Case_Lid_L
10. Use M3 bolts 10-20mm long to attach Case_Lid_L and Case_Lid_R to the top of your new case
11. DONE!

Hopefully I've covered everything here but if you have an issue, leave a comment and I will try to fix it.

Just as a side note, this does involve electronics and wiring and as such I assume no responsibility if you damage your printer, or hurt yourself in the assembly process etc.