After testing the platform with the universal joints, we decided to revert to using the magnetic joints again as the universal joints had too much play within the joint connections, causing the platform to wobble about even while stationary. The best solution would have been to buy better universal joints but as we are days away from the presentation we can only fall back on the magnetic joints.

The application of the 6-DOF platform we intend to present is using the platform to do a 360-degree microscope inspection of a component on a PCB. Current microscope inspection can only scan from a top-down view, our platform would allow the user to inspect the sides of the component for damage such as broken solder joints. The demonstration shows the high accuracy, precision, and range of motion of the platform in order for it to be able to perform such an inspection.

We also managed to adapt our 6-DOF software and hardware to show a 3-DOF system even though it is very buggy as it is in its early stages of development.

3-DOF proof of concept

6-DOF platform V2 with universal joint rods

Microscope inspection (6-DOF application)

Sleep deprivation claims another victim

We finish the 3rd guide plate prototype and start to design the guidance plate attachments that will hold the actuators in place. However, it seems that while we gave much thought to the engineering aspect of the parts, we did not put as much thought into their aesthetics. The colour combination of the parts would probably give any ADM student an aneurism on sight.

Guidance plate prototype v3 and attachments (Discount BlackPink Edition)

Dyllon showing his support for the BlackPink theme

After redesigning the attachments and printing them in a better colour, we attached the actuators to the guidance plate base plate. All that’s left is to attach the platform to complete the assembly of 6-DOF platform V2 for testing.

On the software front, issues with live input continue due to state issues. We need to somehow capture and store the platform’s state when a change in input is detected in order to path the next move. Also, the higher number of commands issued in live input would lead to buffer issues as well. Right now, we are looking into using the built-in G-code commands in Marlin to update the app where the platform is.

In other news, the final presentation for our project is next week. This means we will also have to start preparing for our project application and slides. Hopefully, we won’t lose too much sleep because of this. (Spoiler: we did)

Attachments V2

Actuators installed with guidance and base plate

Assembly Timelapses

Using a mitre saw to modify the aluminium profiles for alternative DOF varients

We started our designing and prototyping for our revised 6-DOF platform. The main objective of this design is to increase ease of installation, eliminate as much error as possible, and increasing the load-bearing capabilities of the platform.

In order to achieve these, we opted to use universal joints as opposed to magnetic joints, redesigned the base adapter plate, and added a guide plate. 

We expect the 6-DOF platform V2 to be robust enough to be our final version and meet our requirements of accuracy and load capabilities.

On the software front, the precision of the output values has improved as we switched from tensor flow to pure typescript for our calculations. Tensor flow has inherent precision issues but if we were to use the platform for applications involving machine learning we have the option to switch back.

We are also starting to experience problems we believe are due to buffer constraints as seen with the python code. It seems that our program is sending commands too quickly and we will have to slow it down to allow smooth movement.

Guidance plate prototype V2 “modification”

Guidance Plate V2 “installed”

This week we focused on the 4-legged configuration. This configuration does not seem to have the same stability issues as the 3 legged configurations. Due to the lower complexity and fewer issues, we decide to focus on the 4-legged configuration first.  We also plan to fabricate a universal platform that can be used across all our configurations.

We received the universal ball joints we ordered a few weeks back and were met with a  pleasant surprise. The joints are able to be adjusted such that one end can act as a rotational joint. This means we can use the same joints for the hexapod as well as the tripod.

Development of the application has progressed and we now have a live input mode which was not possible in the python command-line program. The user can now input values the hexapod would respond in real-time. Further optimization is needed to reduce the latency though.

Universal joint + rod

Quadrapod base adapters

Quadrapod mounting configuration

Universal joint that can act as rotational joint

Live input demonstration