When: 19 June 2019, 8.50am
Members present: All
Update Meeting #2
Even with the new project type groupings, our group was still 6th to present today, out of all 6 of the “Machines/Human Hand” type projects.Β And it appears that our group is forever-cursed with morning slot presentations π …
You can view our presentation slides here!
| Alexis |
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| Carissa |
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| Claudia |
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| Vanessa |
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Felt (get it) pretty good about how our presentation went! Dr Ho and the other assessors were more relentless today in terms of interjecting during presentations to ask questions or criticise work (rather than waiting til after the presentation), but they didn’t interrupt us during our presentation β¨ !! The questions they eventually asked were answerable using our appendix, or easily explainable as they were questions we were already deliberating on during our earlier discussions. They advised us to focus on the main body for the time being, which was already our plan. Their other concerns were the precision of the needle, which we handled all right.
Our supervisor Mr Hanyang ended off the Q&A by affirming that we’re making good progress! π°
More Comments from Mr Hanyang
In the 5-minute break between Group A and Group B presentations, Mr Hanyang visited Claudia and Alexis in the M&T Lab to quickly discuss the project. We showed him the felting needle and explained to him more clearly what we had planned for the main body, as well as the Linear Actuator. He agreed that the LA shouldn’t be secured to the 3D Printer frame given its weight and bulk, as well as in view of the possibility of the LA vibration affecting needle precision.
For the needle-tubing “connector” and main body interface, Mr Hanyang suggested that we can overcome the obstacle of the protruding screws by using countersinks. Thus there would be no need to include the grooves in the cavity of the main body as planned, and friction can be further reduced.
Afternoon Discussions
Needle-Tubing “Connector” Mk IV
Back in the M&T Lab, we edited the needle-tubing “connector” from yesterday: we now have 6 screws instead of just 2 to secure the two halves together. The needle and tubing are now much more secure. It used to look like a snake π, but now it kinda looks like a lego brick π€ .
Needle-tubing “Connector” Mk IV
We hooked it up to the LA and taped the external tubing to the table. The first time we turned the LA on, there was not enough tubing allowance and so the “connector” was forced off. After some tubing adjustments, it worked as imagined.
Prototype test! The linear actuator is connected to the needle through the tubing, and thus produces a stabbing motion.
The Main Body
After some final adjustments on the 3D model, we sent it for printing. The piece will take more than 6 hours to print, so we’ll probably pick it up tomorrow when we resume work. Here’s how it looks at 51% progress!
The bottom of the left piece looks wonky, we know.
A while later, an error occurred and this piece stopped printing half-way π Thankfully, the most crucial part we needed to test, the grooves for the screws to fit through, were printed. One side was fine, but the other did not fit at all. Back to the drawing board; these pieces would have to be printed again. :”)
Needle + Yarn Feeder Mk II
We worked on modeling the new feeder. We modeled it from scratch again, so that took some time. Other than that, we also gave it a different square-shaped base with some smooth beveling to prevent the cloth from catching on. We also tested our first needle + yarn feeder prototype with the LA and “connector” from earlier. The rough surface of the inner tubing (due to the 3D printing material) meant that the needle would occasionally catch onto the surface and be stuck. We needed a smoother inner tubing.
The solution we decided to go with is to attach a smooth plastic tubing to the needle guide tube, instead of having the interface be just 3D printing material. We plan to use a quick connector adaptor piece to join them together.
We sent it for printing near the end of our meeting session ~
G-Code
Qi Jie helped us to find a way to code for the printer to temporarily stop after each miniscule movement…
Project Goals
- Complete Main Body by the end of this week
- Figure out how to clamp LA to an external structure — Perhaps an aluminium profile with rubber studs?
- Figure out how to secure the outer tubing to another fixed structure (Perhaps another aluminium profile)
- Mount all pieces together
- Replace 3D printer controller with the green open-source controller
- Figure out how to modify the 3D Arduino code for the 3D printer’s extruder stepper motor
- Replace LA’s DC motor with the modified stepper motor
- Assemble everything to form the MVP