I have designed the following modular parts for constructing cases for the popular cascadable dot matrix LED display modules
The MAX7219 Dot Matrix Display Modules I used measured:-
130mm x 32mm x12mm (all approx.)
The design can accomodate any number of these modules by stacking the case parts in various ways.
For a single module you can use either:-
A middle section + 1 male end cap + 1 female end cap.
1 Male end + 1 Female end.
For two modules you can use:-
A Middle section + 1 Male end + 1 Female end.
2 x Middle section + 1 Male end cap + 1 Female end cap.
For Three modules you can use:-
2 x Middle sections + 1 Male end + 1 Female end.
The parts 'click' together by using a tongue and groove system (male = tongue, female = groove).
As designed, the parts print on a Vertex 8400 printer with a 0.35 nozzle and fit together nicely.
The case parts have a slot for the LED modules to slide into and side 'cheeks' that keep the LED devices aligned.
The case also has a front slot to accomodate a piece of 3.0mm thick red transparent acrylic sheet.
The acrylic sheet should be cut to 45.0mm in height in order to be a good sliding fit in the slots.
Cut the sheet to the length to suit the number of modules in use.
The case has ample room in the rear cavity to accomodate an Arduino Micro or an ESP8266 NodeMCU controller board.
I used sticky pads to stick the electronics to the back of the LED modules and then slid the complete assembly in to the case.
I made a small slot in the rear of the case for a USB power lead after printing the parts.
The SketchUp files are provided so that the design can be adapted to other LED modules, controllers etc. I used SketchUp Make version 17.3.116.
If you use a 'brim' on the bottom layer to help the parts stick to the bed
you will have to clean out the groove in the middle section with a knife or similar tool after printing.
The Middle section and End parts take a long time to print (6+ hours on my printer), to check that the tongue and groove system will work with your printer I suggest that you print the Male and Female end caps first as test pieces.
Continuous fitting and releasing the parts will wear the tongue and groove system and the fit will become loose.