Selecting an enclosure for your project
Introduction – a brief history of project enclosures.
Project enclosures not only protect electronics from the elements and provide a way to handle, they also give it personality. Various materials can be used to enclose electronics, such as wood, plastic, glass, or cardboard. The only limitation is the process to create the enclosure. Traditional plastic enclosures are available online and at most electronics parts stores. These cases are relatively inexpensive. Albeit they are easy to get, they have some drawbacks. Rarely do they fit your project perfectly.
Machining custom cases is a tasking process. 3D printing can simplify this process by using CAD files. These files can be created, modified, and shared online. This enhances the entire build phase.
Having a 3D printer may not be an option for some, so printing services are key. Shapeways provides a method for creating enclosure models with CAD programs like Sketchup and Meshlab. Websites like Thingiverse can be used as a model source. Using the CAD program, the enclosure can be designed to meet the needs of the project.
However, not all enclosures fit this design. Enclosures used in research and development are problematic. Once the project is done, the used cases end up as waste. This makes the costs of manufacturing an enclosure wasteful.
Recently I came across an item that was presented at a Google IO event. These VR headsets use an Android smart phone as the display screen. What’s clever is the headset is almost entirely made of cardboard.
A recyclable enclosure for development is much better suited for R&D than traditional cases. MCM Electronics provides a way for folks to do this themselves. Having the option to bulk order these seems more practical than creating them one by one, which could be spent developing. Guided is a manufacturer of custom cardboard packaging. It’s a perfect fit. When the project life cycle is complete, the enclosure is recycled.
Purpose – projects that have different enclosure requirements
I’ll go over these options with some projects that have a need for enclosures. The first is a compartment for a helmet camera, the next is a lobby video kiosk, and the last is lab equipment for up coming course work.
- The compartment is needed to mount a mobuis camera to the helmet. I have a mount design to base off of, so I won’t need to design it from scratch. It will need to be able to handle being outside and exposure to constant sunlight, heat, cold, or rain.
- The lobby video kiosk won’t be as difficult. It will house a raspberry pi board and will be mounted behind a monitor screen. The unit will be inside. The only concern I’ll have is heat and dust effecting the electronics.
- The lab equipment will be handled and moved around. The only issue is keeping it enclosed to make work easier. The setup may change so having an enclosure with low costs will be key. I would also like to have the ability to fabricate quickly.
These scenarios should cover most enclosure options and will give us a comparison why one is more suited than the other. Let’s begin.
Details – making an enclosure that best fits the project
We’ll be using 3 examples that have unique design requirements, which are the camera enclosure, video kiosk, and lab gear. I’ll start with the more demanding camera enclosure project and have the others follow.
The camera enclosure is going to be a 3D printed case. The deciding factor was that the enclosure will be out in the elements. That disqualifies cardboard. Another factor is that no standard case is on the market, due to the fact this is a custom built project. This makes 3D printing the best option. Since no standard case exists, this means finding a CAD model online might work. However, I’ll need to draw the model with a CAD program. we’ll be using Google Sketchup.
First thing I did was create a profile on Thingiverse. Since this is going to be a source of models, I figured it is only right for me to share what I create back. Now that the formalities are out of the way, we’re ready to find something to use as a starting point.
The sensor helmet I wrote about in past posts has been a truly difficult project. I have been faced with one complex challenge after the next. One of those challenges is housing camera electronics inside the helmet. I succeeded in implanting a 720p near IR 808-16 camera and a 1080p Mobius camera. However, the Mobius camera operated sporadically. This can be seen here in footage that was the last time it operated.
This was a first for me. I have no previous field experience with the Mobius camera, but plenty with the 720p 808-16 camera. I concluded that I’ll need to do the same with the Mobius to get a better understanding of what it can do and why.
Searches on Thingiverse for Mobius turned up more results than I expected. There was a base housing already drawn and another of the camera itself. I had something to work with now. Using Sketchup with the models from Thingiverse required some work, since the data files are in a STL format. This was solved by installing the STL plugin for Sketchup. I found the steps to do this on Shapeways website.
Now that I had the models, I began to make the changes needed. It didn’t take me long. The finished model can be found here if you’re interested in downloading and printing it. It has been downloaded over 30 times since posting it last week.
With the model done, I submitted it to Shapeways to print. To do this I created my account. Next, I uploaded the file and selected some build options. The site stepped me through this seamlessly. The process was much simpler than emailing a rep and waiting to for a response. It took all of 10 minutes to have my order done.
Since it was so easy to do make the enclosure for the camera, I did a search for the raspberry pi enclosure. Sure enough, I found one, downloaded it, and submitted it. The cost of printing it was double of one already molded, but low enough to make that choice worth it. That takes care of that, now for my final enclosure.
I did a search for cardboard patterns for boxes and found this layout to use. I used cardboard from one of my helmet boxes and cut away. The bends in the cardboard are tricky, so to solve this I used a pizza cutter to seam the joints. This worked well and after 30 minutes, I had a project box for my Arduino and Ethernet Shield. That was easy.
Branching out – where to go from here
The business of enclosures seems like an obvious part in electronics, but based on my past experience it gets overlooked. The ratio of information about enclosures versus the electronics they hold are extremely uneven. For folks entering into the field, this presents a challenge.
The traditional view of enclosures has come to a crossroads, with the vast options available in 3D printing and recycled materials. The hobby builder no longer has to be stuck with the hobby builder look. This opens up a whole new realm of possibilities, by letting the general public see the work that merits attention. Having quick turnaround will let builders finish an idea, instead of it stalling and loosing momentum.
This high tech watch is an example of how and idea unheard of a 10 years ago, is a reality today. Don’t sit on your ideas, make them!
Summary – how it all fits inside
The three examples I presented here are just a small representation of what is available to system designers and builders. The task of building a custom case is simplified with tools like Sketchup, Thingiverse, Shapeways, and most importantly, the designers imagination.
Finding the right fit depends on how the project will be used. It also depends on the experience of how a project will work in its intended environment. There are no shortcuts to this knowledge. At least with enclosure choices, the time for R&D can be reduced.