There is a common practice to test the different components of a device during the manufacturing process and then do a final test to ensure the quality of the device. Future Motion Inc is no different and they have a couple of tests done during the build of the Onewheel.
There is a fact that Future Motion Inc was testing every single controller and BMS during the assembly process of the XR. At the current state, we can only assume they are doing the same for the Onewheel GT. The way you test the PCB on an assembly line is with an in-circuit testing fixture as part of the Quality, QC, control of the board.
The Onewheel GT is having some QC problems and here is the full list of issues. It’s not confirmed if the GT uses a needle test fixture for all components at the current time. What is known today is that they do test ride the boards on a carpet inside the factory.
Testing the Onewheel battery BMS
The Battery Management System, BMS, is coated to protect the electronics, still, there are test points that are used so it’s not fully protected. From a connector point of view, the BMS uses automotive connectors and multiple pins to carry the current to the motor.
Future Motion states that all BMS for the XR was tested at the production facility before being sent to Santa Cruz for assembly. The same test fixture is used at the assembly line during manufacturing. The in-circuit tester for the BMS is running an automated test to make sure that everything is working according to the specs.
Testing the Onewheel Controller
The main controller of the Onewheel is tested with a pin bed test fixture, embedded nails that make contact with all the test points on the board. The fixtures are running an automated test to make sure that all bus voltages, voltage regulations, current and software are running as expected. If everything works the test passes and the test motor attached to the system spins.
There is a test fixture both at the board manufacturer and Future Motion Inc assembly line where every board for the XR was also tested. The Onewheel controller consists of an ARM processor and waterproof automotive connectors but the test point is a weak spot on the board as it makes it not fully coated.
The final test of the Onewheel
The final test of the Onewheel is a test run on a carpet inside the warehouse. This is why there is a small possibility to see some scuffs on your board even if it should be in pristine condition when you get it. Riding on a carpet reduced the risk of getting dirt on the tire and marks on the bumpers.
What is in-circuit testing, pin-needle or bed-of-nails test
The test method that Future Motion uses for the PCB, In-circuit testing (ICT) is the most robust type of PCB testing in existence. The cost is the higher price as a special test fixture needs to be built that can cost tens of thousands of dollars. The cost will depend on board and fixture size, among other factors.
An ICT, also known as a bed-of-nails test, connects to test points and powers up and actuates the individual circuitry on the board. The goal is designed for 100% coverage, in reality, the test coverage is closer to 85-90%.
In-circuit testing uses fixed probes laid out in a way that matches the design of the PCB. The bed of nails tester simply pushes the board down on the bed of probes and starts the automated test. The probes check the integrity of the solder connection on the PCB and can allow for testing the functionality of key components.
Usually, ICT is used on a “mature” product design of the PCB with very few revisions expected. At the moment it’s not known if the Onewheel GT uses a fixture or not.