P15041: Smart Walker III/public/
Build, Test, Document
Table of Contents
Final FilesThe final working files for Smart Walker 3 can be found in this folder. This was the state of the project at the end of MSD2.
ScheduleThe schedule, broken down by subsystem, is located here. In a more general sense, the project tasking (what each team member is assigned) can be found here.
Test Plans & Test ResultsThe test plans for the walker can be found here.
Phase Assembly Breakdown
ME Weeks 3-5Strain Gauges
- Several iterations of the clutch actuator were printed and tested. Small modifications were made and the final piece was implemented and tested. Though successful, testing revealed that supplying 24 volts to the solenoids makes them much more reliable than supplying 12 volts like the current configuration.
- The case and case backing were both printed. There was a small amount of movement when the camera was placed inside. This was due to the large tolerances that 3D printed components naturally have. Material was used to pad the camera which stopped the movement.
- The drawings for the new bearing plates were submitted to the machine shop.
ME Weeks 6-8Electronics Enclosure
- The seat was disassembled so the enclosure could be mounted. Holes were drilled in the steel plate, the enclosure was bolted to it via the holes, then the seat was reassembled. This was all done after the hardware was secured inside the enclosure. The hardware is easily accessible by lifting the seat.
- An unsuccessful attempt was made at implementing BMI sensors into the handles. It was difficult to properly place them into the grips while the grips are attached. Since the grips cannot be removed without being damaged, two sets of grips were ordered. This allows the sensors to be incorporated before the grips are permanently attached to the walker.
- The case was modified so that the backing could be secured. We used helicoils so the backing can be bolted on for an aesthetically pleasing, secure, easily removable system.
- The new bearing plates were manufactured and picked up from the machine shop. The assembly was completed week 8.
ME Weeks 9-11Wheel Assembly
- An issue with the bearing plates was discovered upon reassembly. The interference fit between the bearings and the plates was just off enough to not hold the bearings in. All bearings were secured with locktite, and the plates were reassembled.
- After a discussion with the machine shop, we determined that thick foil would be a better material to use for the sensors. We soldered the connections to the foil and then secured them to the handles as shown below:
- However a conductivity test revealed that the foil would not be a viable solution.
ME Weeks 9-11BMI
- The foil was removed and the electrodes from the handheld BMI were implemented in their place. They were soldered to connections and then secured to the grips via a silicone sealant adhesive: