I am on a quest to learn how to build physical things.

Set up GitHub repo structure (models/, src/, main.cpp, bin/, etc). Installed CMake and wrote CMakeLists.txt file.

Learned about different compilers (Clang, GCC, Visual Studio) and configured Clang because I use Mac, it’s preinstalled, will produce faster & more optimized binaries, and has better diagnostics (error & warning messages).

Spent a loooong time trying to solve a bug wherein the compiler couldn't find OpenCascade header files (specifically gp_Pnt.hxx).

Some approaches I took were: verifying that files existed, manually setting the include and library paths, reconfiguring VSCode IntelliSense, rewriting the .json files, adding fallback include paths, testing manual compilation, etc.

What ended up working was changing the include statement in the main.cpp/ file. A tiny and simple fix that took a long time to get to and was so satisfying in the end.

Set up dev environment for CAM, to take my CAD files to the next level.

Installed Fusion360, CadQuery & a CadQuery GUI Editor. The Editor looked like it was from 2007. In the process downloaded and learned how to use Conda, and then realized that CadQuery is just a Python wrapper around OpenCascade.

Downloaded OpenCascade and wrote C++ in VSCode.

Exported a STL file from Waffle Bot's Onshape environment into Fusion 360, converted it into a mesh, and simulated 2D Pockets & Contour (wow this is so cool).

Exported the toolpath as g-code, read it in VSCode, and visualized it in NV Viewer!!

Spent 4h organizing my flat and unpacking everything I hadn't unpacked since I moved. Environment makes a huge difference. It was a mess and took way longer than I thought but now it looks sick. Yeah, I can lock myself in here to build 24/7 😎

Added details and entries for the last week on this site. Went through 3 iterations to implement proper image, bullet point and paragraph formatting. It took time to compile all of the information into the log, it will go so much faster in the future as I just update it daily.

3D printed the leverage robot arm so that I could study it in real life. (It had the STL but not the STEP files so I couldn't really see what was going on.)

Most of the day was spent debugging servo connection to the Raspberry Pi. After battling with improper grounding, dead or zombie servos, power starvation and weak jumper wires, I was able to wire a DC power supply to the servos that survived (RIP 4 HS-311s that I probably broke by twisting them around too much during assembly). Now I know how to diagnose low/no current draw conditions, debug power delivery with a bench supply, PWM logic and signal grounding.

Even with a few servos working with the extra power supply, they were still too weak to move the arm. I spent the rest of the evening looking at other robot models to base my redesign off of. I found one that uses servos at the base + a lot of leverage, and decided to use that one as my example for v2.

I designed servo hats for MG995s, two versions of a v2 arm component, and 1 version of the v2 base.

Finished first full version of the WaffleBot, assembled and connected it to the Raspberry Pi, and found that the HS-311 servos did not have enough torque / arm was too heavy so they couldn't lift it up properly.

Also spent 3.5h in the morning at a contract manufacturer seeing every step of the PCBA process, including BOM, procurement, SMT assembly, stencil printing, pick-and-place, ovens longer than my bedroom, through-hole, optical inspection and more.

This CM sets themselves apart by always shipping their products on time and having a rework rate of <0.1%. For reference, most CMs have rework rates in the mid-double digits and are regularly 6-8 weeks late. The guys I visited are of the highest caliber.

Their trick is to have tests and checks at every single step of the process. It is actually not adding more work - it saves time and money by catching mistakes as early as possible.

My host had been brought in to increase efficiency of the factory by automating as much as possible. I haven't met anyone with more integrity or craft. He carefully explained to me the parts of the process that need to be done by hand, and others that could be automated. He let me sit in on meetings where he trained his team and developed software towards these goals. The most curious thing I noticed was that he always asked how much time something took, and his employees responded down to the minute, usually between 2-15.

Found a different gripper online, 3D printed and assembled it, designed the wrist joint and mount that it would attach to.

Ordered additional M1 screws for horns and sticky soles that I can add to the robot base to make it even sturdier.

Discovered the mirror tool in CAD which makes my 2D drawings so much faster.

Am finding locking a bit difficult. So far am designing all of the components with holes for screws and manually screwing them in with hex nuts on the other side, but sometimes the parts are so small that it gets inconvenient to attach them. Don't quite understand yet how to drop a lock nut into a print / make threaded inserts, but I don't think I'll need that for this version.

Designed and added the first part of the arm to the assembly.

Also designed the elbow and second arm part.

Learned how to design parts in context and import STEP files of specific components from the internet. Also learned fasten/revolute mates and made my first assembly.

Learned how to make holes in CAD. Game changer.

Built v2 of the Waffle Bot base, this time not just a cubic block of PLA with a rectangular cavity in it (lol) but one properly optimized for sturdiness, attachment to the servo and quick 3d printing. Also designed my own servo horns because I didn't have small enough screws for the ones that came with my servos. Went through 3 versions. Was able to create ridges that attached onto the servo perfectly.

I had pain in my hip which turned out to be a torn labrum so I spent the last few days in the hospital / battling with insurance / getting ortho advice / recovering. So the last few days are blank but now I'm back!

Sketched out how Waffle Bot needs to look like and made some measurements relative to the size of the toaster and a waffle. Realized 3DOF will make it very hard for Waffle Bot to pick up waffles so I started working on a 5 DOF design.

Read up on DOF and studied how others have built their robots. I decided I want to start as simple as possible with 3 DOF.

Got bogged down trying to assemble the servo gripper before realizing the print was missing two parts. Even after printing those wasn’t able to assemble it, turned out that the stl design was faulty and the holes for screws and hex nuts were size mismatched. Don't trust the internet I guess.

Downloaded and set up Raspberry Pi environment. To do that I first pinged RPi via local host name on my network, then via IP address.

Set up shortcuts to be able to securely SSH instantly. Used ZeroTier to connect my Pi to a network ID, generated a new private & public key, renamed the RPi localhost and set up passwordless login. Set up first test .py and .txt files.

Printed a servo gripper off the internet and 1/4 of all LeRobot components and then realized I don’t have the right motors or a few other pieces. Ordered them, but some parts will take ~2 weeks to arrive. Decided to design my own robot from scratch.

Assembled my BambuLab 3d printer!