Making your own enclosure for your electronic project, is a very rewarding way to showcase your creation.
To help you do this I have included my own experiences of making enclosures, over a hundred so far, and will share my procedure below.
When designing my electronic project I make sure that I keep the limits of 3D printed parts in mind, and also exploit all possible configurations of the enclosure.
If including a PCB populated with components ( display, buttons, leds, and so on ), you may need to use panel mount components wired to the PCB, or design cut outs for the PCB components.
Other features could include removable battery cover, and internal battery terminals, or lcd bezels, or other features required by the system.
Before printing it is good to check the design to make sure that the print is oriented properly, that all measurements are correct, and that all openings in the enclosure for buttons, switches, etc., are in the correct position.
This first check is the most important, as a silly mistake in a 6 hour print, is very frustrating, and a waste of material. If this does happen, you can check all other dimensions against the actual print, making sure the next print is correct.
The next step is relatively simple, check the 3D printer is setup correctly, that the correct ink is loaded, and the printer bed has been coated with Anti-Tilt Glue for 3D Printer Hotbed.
Slice the 3D design using your favourite slicer, make sure it is oriented correctly, and then print.
There are two stages to my print finishing technique.
Stage one – repair
3D printing is built layer upon layer, check the print for any gaps in the print, sometimes there are layers that have gaps, and even with no gaps, it is obvious that it has been 3D printed as you will see the layers, even with very fine resolution, sometimes there are also colour changes, making the print look striated.
I like to remove all signs of 3D printing, I use a grey ink as all my prints are spray painted, and the grey makes it easier to see faults, and easier to prime.
First I sand the enclosure using a fine sandpaper, sanding out any ridges, bumps, or lines. Then I use a plastic putty to fill any gaps, or lines, in the enclosure.
When the putty dries, it shrinks slightly, so check and reapply putty where needed. Then sand again with a fine sandpaper.
When you are happy that you have achieved a good flat finish, sand again using Micro Mesh ( or similar ) graded sanded pads from 1500, 1800, 2400, 3200, 3600, 4000, 6000, 8000, to 12000.
The enclosure is now ready to move onto stage two.
Stage two – paint
I mainly use two type of paint, the choice depends on the usage of the enclosure, if it needs to be hard wearing I use Lacquer paints, for internal surfaces, and non hard wearing, I use Acrylic paints. Sometimes I use Enamel paints for extreme hard wearing.
I use an airbrush for painting, with a booth with fan and filter for extraction of paint particles / fumes, this is especially important using the lacquer paints. The lacquer paints are thinned using Tamiya lacquer thinner and retarder at a ration of 1:2 1 part lacquer, and 2 parts thinner.
I start with a first coat of paint ( undercoat ) then leave to dry, lacquer paint dries much more quickly then acrylics. Once dry I inspect the enclosure for gaps and lines again, as I have found that some faults are only noticeable once painted. If any are found I use a graded 3200 micro mesh pad to key the surface before applying more plastic putty.
Once putty is dry re-sand ready for painting again, the enclosure at this point will look quite patchy with areas of no paint, paint, and bare putty. This will all go away with 2 – 3 coats of paint applied thinly, allowing paint to dry for the proper time between coats, if the paint does not dry properly then a fingernail will easily dent the finish.
After painting is finished, it is time to apply any stencils, decals, or other effects to the finshed surface. Then apply 2-3 layers of a clear lacquer to finally protect the surface from scratches.
To give the enclosure a really fine finish. I like to use a clean non-lint cloth with a drop of Micro-gloss liquid abrasive to flatten and polish the lacquer surface. Micro-gloss is a concentrated formula for the removal of scratches, haziness, and halos from plastic surfaces. I will repeat this last procedure until I am happy with the final finish.