The Challenge
OTTO Motors observed that the existing encoder extender held excess mechanical stress on the SMD connector, raising concerns on its reliability to maintain electrical connection in operation. The goal with the design was to shift mechanical stress off the mating connector and onto the PCB creating a more robust and reliable connection system, by integrating a through-hole component over the existing SMD component.
For this design change to be fulfilled, the project needed to incorporate two main changes. Namely:
The PCB/PCBA to fit the new connector whilst also updating them with contemporary labelling and standards.
The harnesses, left and right motor sides, updated with a new mating connector.
Though a rather simple design, it was important to choose the right connector, create adaptable harnesses, and ensure proper fitment in the robot assembly, in order to fully fulfill the needs of this project.
PCB in Design
Manufactured PCB
Soldered Connections
PCB Design
The encoder extender PCB was designed to be soldered to two components (encoder, connector) ensuring structural integrity, that would later be mounted onto the motors of the OTTO 1500 robots.
The design involved solder pads for the encoder, mounting holes for the motor, and a section of pads for the through-hole component. The extrusion in width was created to allow for a better hold when installing the connector.
Other designs were catered to industry standards, such as polygon pours, labelling, fiducials, keep-out layers, etc.
The prototype was manufactured and fit-tested to the harness.
In-House Assembled Harness
Traction Harnesses
Both a component (for the mating connector), and a symbol (to represent the M8 mating site) were created in VeSys component. The remaining two of the other connectors were acquired from existing libraries.
A multicore was created for the mating connector and the main schematic was updated so that it could synchronize to the harness drawings. From the drawings adjustments were made to the wiring assignments, strip lengths, and the BOM to make sure it reflected the right numbers.
The image on the left reflects the harnesses built in-house after having sourced the necessary off-the-shelf components.
Traction Right Bulkhead Harness Drawing
Top-Left: Standard drawing notes
Top Right: Bill of Materials, multicore specifications
Bottom Right: Legend, Title, PN
Center: Harness schematic w/ connectors, connection specifications
What I learned
Throughout the project, I was able to significantly strengthen my skills in PCB and harness design. I was able to learn a great deal with working in both Altium and VeSys, understanding how the software works and being able to properly design drawings that meet specifications and adhere to engineering standards. Additionally, learning how to select and source certain parts for design helped me better understand the foundational framework that goes into building hardware. From start to finish, I was able to grasp both the digital and physical sides of electrical hardware, guiding my comprehension on the entire process that goes into developing new hardware.