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Some progress?

So, here is the good news:

• I created the leg of my robot which is around 10cm each to maximize the height while keeping the robot stable
• Added a container to hold my servo motors. The servos are flipped so that the contraption will work. You will see later
• Added the fin attachment to bend the robot. I’m struggling to get the fin to connect with the servo horn as a joint

The bad news:

• I know I said I don’t care about aesthetics, but the leg does not seem like a leg or looks like it will stand 💀
• For some reason it took me like 20 minutes to figure out the dimensions to fit the servo motors.
• I lowkey don’t know if you are supposed to be free-styling-ish dimensions (since I’m just inputting dimensions that seem to resemble what I’m going for)

What I plan on doing next:

• So, I’m going to work on the spring joint which allows for the leg to actually bend
• I’ll actually force myself to 3D print the parts to test them out (I’m lowkey just afraid of failing)

My mood: 🤨(Pls work)

I went back to the drawing board.

I analyzed/sketched how the robot dog legs work. And I know it’s crazy, but I was confused what that small little linkage leg was for.

I realized the servo #1 was controlling the little linkage leg in order for the robot to bend. The analysis was really helpful particularly with how I should design the shapes of my leg because I was too busy looking at the details/aesthetic of the linkages that at the core, the linkages are really just circles or rectangles .

What I plan on doing to avoid CRASHING out is to literally just get the key linkages. I will focus purely on the mechanics before stressing about its appearance

My mood: 😐(I still gotta model this in CAD)

My leg is cooked.

I did not like my previous leg and now I am referencing this dog design because it has more degrees of freedom. The previous design only allowed the dog to shuffle NOT walk.

I want the dog to walk as in lift its feet off the ground. I also want it to be able to dance.

Apart from the fact that this linkage design is much cooler from my earlier design, it also will make the legs more lightweight because now, the servo motors will be attached to the chassis rather than at the knees.

While researching, I also realized some basic physics that will indicate the maximum load the dog can carry. That is: if the length of the leg is 100mm (10cm), then if I power it using MG966R which has a torque range of 10.5-12 kg * cm, then on that foot it may carry up to 12/10 = 1.2 kg or 2.4kg on two legs.

So, I learned that basically I need to keep the dog as lightweight as possible which of course I can do by: making the dog symmetrical, move the motors up, and ensure the design is optimized.

Now, the only problem I have left is uh building the linkage. It is the most important, so I want to get it right before moving on. I will test it using a plastic servo motor.

My status rn:😭

So, I’ve had the idea to build a robot dog like the one from Boston Dynamics and given that I have tinkered a bit with Fusion 360 as well as with PCBs from previous Hack Club programs I’ll finally start building a ROBOT!!! I am lowkey scared about all the physics that I will need to code, but its fine.

The goal of the robot is:

1. To walk (at least move)
2. To have different sets of movements
3. If all goes well, which usually does not, I hope to add a mechanism that will carry items inside of it.

By the way: I am also being heavily* inspired by James Burton’s design, but I will iterate and likely change it depending on how it turns out. I already changed some of the design choices, since some of it looked unnecessary, and also I will make the robot look cute like a puppy. :)

Here is what I did:
So, the robot dog will use six servo motors and the design is pretty clever in its motion. But for now all you need to know is the bending of the legs will be controlled by one servo motor and I have already gotten two joints to rotate! The leg is supported by two thicker slots and then it currently has one linkage. But I’m probably going to tinker more with this linkage design. Also I have no clue whether or not this foot is going to be stable.

Also, I am pretty broke***, so I hope to keep the budget pretty low even though I like I don’t have any metal servo motors and they cost like $5 a piece 😭