Arduino case (in the case shown for a Leonardo)
This is a bit of a tidy up post as I promised I would post these designs for the Greenpower project. There will be a follow up posts on the sensor cases and Arduino Mega case that we finally used, as well as the Raspberry Pi Web server case which links the vehicle telemetry to the clients web viewers used to monitor vehicle performance.
This unit was used in our Greenpower F24+ race car project (http://www.greenpower.co.uk/), as the prototype and test data logger. It is also used for general Arduino and PicAxe projects.
Sealing peas used for cable exist are AMP Supereal 1.5 peas Radio Spares (rswww.com) RS Stock No. 314-1176 TE Connectivity Mfr. Part No. 281934-4 (http://uk.rs-online.com/web/p/connector-wire-interface-seals/3141176/). When fitting pea seals, ensure the holes are the correct sizes and lubricate with soap to permit insertion. Alternatively use your favourite silicone sealant in place of pea seals. To restrain the cable internally use a cable tie or similar.
This case ( without with the test USB access port ) has run in 4 races in the rain and been left out doors in a tool shed over the winter. When correctly printed the case is dust, spray and splash proof.
If you have poor or incorrect layer bonding or poor seam re-starts, consider spraying the case with a plastic filler or otherwise treating the surfaces for improved performance. As the volume of the interior is considerable there may be some minor pumping action through cables passing into the case if cable ends are not sealed.
The ends are printed separately to allow different features (sensors, indicators, switches cables etc) to be added or removed as necessary. Printing an additional slightly modified version of the centre section allows an Arduino Mega 256 to be housed using the same set of components.
Recommend stainless steel screws and nuts if the item is expected to get wet.
An elastomer bumper is included in the STL files which was used to protect the module ends. This optional item is not recommended where full sealing is required.
STEP files are included in a ZIP file to permit easier modification where needed
Note you should take your own steps to validate sealing integrity as printing quality can be so variable.