Yet another day, we rise to the gentle embrace of the morning sun and the ever-so-familiar song of the “uwu” bird. And of course, the first thought on our minds is that damned clamping mechanism.
Luckily, Qian Xin had delivered us some great news the previous week that we had just been assigned a mentor, by the name of Savior Jie Huang, who’s a CN Yang alumni in Mechanical Engineering and is currently doing PhD studies in the same field. Will he deliver us from the pain of the clearance problem? We walked (or took the bus) with great anticipation for this mysterious hero, expecting him to disseminate nuggets of infinite knowledge to us like a tree dispersing its seeds.
Unfortunately, he was as equally stuck as us on the problem. He suggested some ideas on telescoped arm (basically a retractable arm system), but we had already explored that idea and it’s too commercially difficult to source, not to mention it will struggle with the load. It won’t really help us with the clearance method either.
LUCKILY, he does have some working knowledge of mechanical simulations and SolidWorks, so we passed our assembly files to him for him to tinker around a bit. Our attempts at SolidWorks (while very valiant) had always ended up in the whole arm system disintegrating into many parts due to a SolidWorks glitch whenever we put in the actuator sub-assemblies (they need a length limit so they don’t overextend or overcontract). Not so valiant, I guess.
As for the clamping problem, what we really needed was a new way to clamp the whole unit and avoid the metal wires, the metal handle and the roof of the train…
After Jie Huang left, some slightly better news: the heavy-weights of our lifting system, the linear actuators arrived! These were the 3 x 500mm Linear Actuators (+ 8 Actuator brackets to attach these to the 3060 aluminium profiles)
Wonderful news! We could finally toy around with these actuators…Nope. How could the day go so well? Of course not. The actuators were actually rated 750N, not the 1500N we had selected.
HOWEVER, we also knew that these were for the secondary arm and not the main arm, and the load they would have to support is just that of the pneumatic unit and of course of the secondary lifting system itself. Furthermore, we’ll be using multiple actuators, so their combined carrying ability should be well within safe limits.
As a rough test, we also tried to lift one of the tables in the MnT lab with the actuator ALONE, and guess what, it managed to do it without any problems. That’s awesome news that we didn’t get a faulty actuator.
In some other news (while still thinking about the clearance problem), Tony instructed us to source for more nuts, screws and brackets for the aluminium profiles, as he reckoned that what we bought might not be enough (given that some of them were bound to be slightly defected as well). Thankfully, Terence was around in SPMS, and he readily agreed to us dissembling his prototype, and mind you, that was the best craftsmanship prototype for last year! How gracious of him and his group.
Also, not much new inspiration hit us, so we proceeded with the 2x heavy duty ball joints, which also just arrived. We needed a way to secure the heavy duty ball joints to the whole clamping system. To ensure maximal fit, we decided to custom-design the ball socket instead of buying one. Ideally, this double-ball-joint system would allow us to rotate the clamping mechanism quite freely and also allow the manual sliding motion for the technicians to lock the pneumatic unit into the train.
Our first prototype for the socket looked something like this! The important thing was to make sure that the inner curve of our 3D print fits the ball as much as possible, which it did! Thank you to the Ones above. Our day is slowly getting better.
Before we knew it, it was already 6+ pm, so we decided to call it a day. The clearance problem continued to linger over us, and it was quite clear (pun intended) from our facial expressions. We decided to heed Tony’s advice, and just wait for that “shower” moment. Good bye, for today!