Encoder Extender 

The Challenge

OTTO Motors discovered issues with a PCB on the OTTO 1500s, needing to be redesigned with a new connector. The intent was to shift mechanical stress off the mating connector and onto the PCB creating a more robust system, while also ensuring better integrity of electrical connections. 

For this design change to be fulfilled, the project needed to incorporate two major changes. Namely:

Aside from that, there are to be smaller additions such as new PNs, project instantiations, official change notices (ECOs, ECNs, PROs), etc.

PCB in Design

Manufactured PCB

PCB Design (Revision 1)

The encoder extender PCB was designed to hold two components (encoder, connector) while maintaining structural integrity, that would later be mounted onto the motors of the OTTO 1500 robots.

The principal designs were centered around 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 were manufactured (as shown) and fit the components well. 

PCB Design (Revision 2)

Upon inspection of the Rev 1 Encoder Extender PCB, it was found that the arrangement of nets did not match the color code of mating connector. While the functionality would work as expected, incorrect color coding is often frowned upon by engineering standards. 

Therefore, another revision was made, rearranging the nets and traces to correspond to the correct color code of the mating connector. 

For this change to fulfilled, nets were reassigned and I created two simple vias which I then traced on the back of the PCB to avoid overlapping of traces.

Routing of ENC_GND and ENC_+5V through vias

Net Assignments


Traction Right Bulkhead Harness Drawing

Assembled Harnesses

Traction Harnesses

The harnesses was designed to have a mating cable to the M8 connector, as well as two other ports of the motors. 

I first created both a component in VeSys component for the mating connector and created a symbol to represent the M8 mating site. I pulled the remaining two of the other connectors from existing libraries.

 After having done so, I created a multicore for the mating connector and updated the main schematic so that I could synchronize it to the harness drawings. From the drawings I adjusted wiring assignments, strip lengths, and overall made sure the BOM reflected the right numbers.

On the left you can see the harnesses built in-house after having sourced and ordered the necessary components.

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 softwares 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 framework that goes into building hardware. From start to finish, I was able to grasp both the digital and physical sides of electrical hardware, expanding my knowledge and skillset in electrical engineering.