I wired up a rocker switch for LED lights that are wired directly to the power supply on my Ender 3 Pro, and needed a way to mount the switch. The box fits a rocker switch that is approximately 30mm x 20mm (https://www.amazon.com/gp/product/B07QR4ZKL8/). The screw holes line up with the v-slots on a 4040 extrusion, but are sized for M3 bolts. I used the M3 T-Nuts found here: https://www.thingiverse.com/thing:3050607.

The walls on the box are a bit thin, so may need to make sure you are well-calibrated, and you may want to use PETG instead of PLA, as PLA may be a bit too brittle at that thickness.

Creality

Ender 3 Pro

No

No

0.2

15%

Printed on my Creality CR-6 SE for my Creality Ender 3 Pro

Quality

Layer Height: 0.2mm
Initial Layer Height: 0.2mm

Shell

Wall Thickness: 1.6mm
Top/Bottom Thickness: 0.8mm
Enable Ironing
Ironing Pattern: Zig Zag
Ironing Line Spacing: 0.2mm
Ironing Flow: 20%
Ironing Speed: 45mm/s

Infill

Infill Density: 15%
Infill Pattern: Gyroid
Infill Overlap Percentage: 30.0%

Material

Printing Temperature: 240C
Build Plate Temperature: 80C
Flow: 97%

Speed

Print Speed: 50mm/s
Infill Speed: 100mm/s
Travel Speed: 150mm/s
Initial Layer Speed: 15mm/s
Z Hop Speed: 5mm/s
Number of Slower Layers: 2

Travel

Enable Retraction
Retraction Distance: 6.5mm
Retraction Speed: 25mm/s
Z Hop When Retracted
Z Hop Height: 0.2mm

Cooling

Enable Print Cooling
Fan Speed: 100.0%
Initial Fan Speed: 0%

Support

No Supports Required

Build Plate Adhesion

None

Designing the Rocker Switch Box

I started the design by measuring the dimensions of the rocker switch along with the connections that are behind the switch, so that most of the connection wiring is enclosed. The top and bottom of the switch have pressure tabs that hold it in place, so I used my caliper to measure the vertical length of the switch with the tabs included which was around 30.5mm, and subtracted 0.5mm to allow for some pressure fitting.

The horizontal measurement was at 20mm, and after researching design a bit in the past, I learned that a 0.5mm gap is usually enough to allow for a snug fit, so I went with 20.5mm.

The depth measurement was at about 30mm to the end of the connections when attached to the back, so I added a bit of extra to somewhat cover the wiring. In the end I used 35mm for the depth.

From there, I took my measurements to Tinkercad, and created the "box" where the switch would be housed. I started with the shell of the box, and figured that a 2mm shell would be enough, so I created a box that was 32mm x 22.5mm x 35mm in dimension. I then placed a box hole in the middle that matched my dimensions after measuring: 30mm x 20.5mm x 35mm.

I then determined that I needed a "platform" or screwing tab in order to connect it to the printer, so I dropped another box onto the design that measured 32mm x 50mm x 4mm. I decided that 4mm would be enough to give it enough thickness to offer strength without being too bulky. The 50mm length was simply me doubling the 22.5mm size of the box (45mm) and then adding another 5mm for spacing for the screw holes.

I then dropped in some cylinder holes at 3.5mm x 3.5mm (round) to fit M3 bolts 5mm from each edge, which aligns with the v-slot on the 4040 extrusion.

Additional Thoughts

After printing the rocker switch box, I realized that the shell for the box was maybe a little bit thin. I printed it in PETG, which seems to be strong enough, but if it were printed in PLA, it might be a bit too brittle, and I probably should have increased the shell thickness a tad bit. I'm thinking another 1-2mm would have been appropriate, but this fits my needs just fine.