3D Printing the Mailbox

Gmailbox Parts

There are six 3D-printed parts which make up the Gmailbox:

  • Mailbox Bottom
  • Mailbox Top
  • Servo Holder
  • Mailbox Cover (Front)
  • Mailbox Cover (Back, Micro-USB cutout)

What if I don't have a 3D Printer?

Not to worry! You can use a 3D printing service such as 3DHubs or MakeXYZ to have a local 3D printer operator 3D print and ship you parts to you. This is a great way to get your parts 3D printed by local makers. You could also try checking out your local Library or search for a Maker Space.

Slicer Settings for Cura

Layer height: 0.2mm
Line Width: 0.38mm
Wall Thickness: 2 line count
Infill: 20% triangle pattern 
Print Speed: 60mm/s
Extruder/Bed Temps: 220c / 60c
Supports: Nope!

CAD Assembly

This animation demonstrates how the parts fit together. The assembly was designed for 3D printing and optimized to print without any supports. The front cover hinges onto the case while the back cover snap fits shut. The bottom cover is clamped to the case. The STL files are oriented to print "As-is". 

Design Source Files

The enclosure assembly was designed in Fusion 360. This can be downloaded in different formats like STEP, SAT and more. Electronic components like the board, displays, connectors and more can be downloaded from our Fusion 360 CAD parts github repo.

If you need another format for your printer, use the following link:

Tap Mounting Holes

The mounting holes in the bottom cover and case will need to be tapped using an M2 and M2.5 tap tools. This will create threads inside the mounting holes to allow precise fastening.

Making Threads

A tapping tool has coarse and sharp edges that are designed to scope out excess material. A tap handle is used instead of a drill to minimize friction caused by rotational speed (PLA plastic melts!). Slowly twisting the handle produces better results. Try to be as straight as possible when tapping holes.

Tap Holes in Case

The two mounting holes on the side of the case feature geometry optimized for 3D printing. The part is printed vertically and produces holes that have slightly tighter tolerances. Use an M2 tapping tool to create threads in the mounting holes.

Tap Plate

The two mounting holes in the flat plate are also M2 sized and slightly tighter. These were also tapped. The M2 size tapping tool has a very small shank that did not fit my tap handle – So I designed and 3D printed one!

Install Plate

Place the plate over the side of the case with the ovular opening. Line up the mounting holes. Insert and fasten two M2 x 12mm flat head machine screws.

Mounting Screws

Continue to fasten the screws until the shank is about halfway through the case. Hold the parts together while fastening. 

Mailbox Parts Assembly

Once all of the parts are printed, a dry fit test will ensure everything fits properly or may need a bit of sanding. Start with the case and back cover parts first. Press the back cover onto the end of the case with the flat side. Fit the lip over the case on one side and press fit the other side to snap the edges together. Insert the bottom cover in between the rail of the case and slide into the back cover. Fit the nubs from the front cover over the dimples in the lower corners of the case.

This guide was first published on Aug 22, 2018. It was last updated on Aug 22, 2018. This page (3D Printing the Mailbox) was last updated on Aug 19, 2019.