PIQ-03

MAY 2024

I became really intrigued by imitation learning and reinforcement learning. While simulations are cool, I was more interested in applying them to the real world. So, I decided to create a robot arm that could be trained to pick up and sort objects. Additionally, learning the ACT (Action Chunking with Transformers) algorithm from the paper "Learning Fine-Grained Bimanual Manipulation with Low-Cost Hardware" by Tony et al was also on my to-do list.

CAD

CAD took a while to get used to. I previously subscribed to Scott Yu-Jan, a Google Product Designer. His YouTube videos are artistic, and the details in each of his clips are incredibly creative. Please check him out!

His subscription included a couple of CAD tutorials from which I learned a ton. I reduced the number of layers and layer sets in my sketches by more than half. Not only that, but sketching became a lot faster. Example below.

After about 2 nights of work, it was time to print.

Printing

I know I could not do this with my Ender3 printer. The prints were absolutely horrible no matter how much tuning I did. The nozzle also blew up.

I had been eyeing the Bambu Labs printers, but they are pricey. So, I saved up by ramping up my dog-sitting services. With an online sale event and $670 (with tax), I was able to buy the Bambu Lab P1S.

It came in a large box labeled fragile with careful packaging. Bambu doesn't mess around.

I set it up and printed my first model (a benchy), a 3D test print of a boat in just 15 minutes. It was so fast, my jaw dropped. I just hopped in and out of the shower, and it was done. I didn't believe it, so I printed another one and gave it to my brother lol.

The crazy part was that it wasn't even on 'ludicrous' mode. I could print and watch everything from my phone or laptop. It even records timelapses!

Because I was short on time, I could either continue to print and iterate on my 3D arm design or grab some CAD files from the internet, which is what I ended up doing. I grabbed the CAD files from here and started printing them overnight. I woke up to amazing prints. Let me tell you, it was a great morning.

I put it together according to the tutorial, but lots of parts were missing. So Amazon came in clutch. Everything was coming together... almost.

The videos were great, but there are a ton of nuances that were missing when building this robot:

Problems

1. Testing

Testing the servo motors one by one. Burnt around 4 servo motors total.

Potentiometers also were tested one by one.

After I replaced the motors, it still was not powering. Spent hours tinkering only to realize that the Jack plug was burnt out as well, so I had to replace that.

2. Wiring

The wiring wasn't working according to the tutorial, so I had to completely re-wire everything myself. YouTube was my teacher, and eventually, I got the potentiometers and the servo motors to coordinate with one another.

WIP!!!