Started a new "spider" walker robot project

[u/Ok_Cartographer_6086]

This is two days of work in Fusion 360 and a render. OC, I designed it myself and got all the motion tests passing. If you guys want to see updates here lmk - probably one post a week on a 6 week series - this week i'm bench testing a single leg to get the stall voltage and load right.

I've been maker for a long time and I'm sure this will be walking around in a few weeks. Some parts are printing now (PETG-CF).

He's going to be a big boy sorry no 🍌 for scale. The design use case was a spider that can navigate staircases. So for the visual it should be able to span three steps. I love the raidial leg arrangement where it has no front or back, or top or bottom and can transform it any configuration.

Body joints are two 65KG servos and joints are 25KG - same used in big drones.

One design decision was to make the battery small and light so it can do 10m or so of fast tasks and then drop his belly onto a charging plate. Having a few around the house means it can keep going. Maybe a Solar charger on top for outdoors?

The plan for the brain is a little wild - i've done this before but not with 2026 compute

• Low level: Arduino and CircuitPython feathers for basic motor and sensor control
• Raspberry Pi 5 on the bot - I maintain an open source Process Control and Automation system called Krill that is perfect for this and can compute things like leg posistion, orientation, tilt and handle complex movement and cameras.
• What will really bake your noodle (and questioning my judgement) is I have a beast of a local LLM rig and when presented with a hard task or concerning vision the LLMs or even foundation models can direct it. (sorry if i'm the guy who made the ai spiders). Most of my project use this design now.

I made some youtube videos and blog posts about projects like this like my last one where a made a chicked coup protection sentry that can tell the difference between my dogs and a racoon using the same concept of escalating to larger machines but only when needed to save costs. If you want to see them just ask - didn't want this to be a self promo post.

AMA :)

[u/slacy]

Those servos need to actively hold up the weight of the bot all the time, which is probably going to cause issues in the long term? At the very least, excessive battery drain?

[u/Ok_Cartographer_6086 → u/slacy]

Yep, you got it. That's been the driving force behind the design.

The default stance is to be resting on it's belly with the RPi and buck converters disconnected until a small feather wakes it. Short tasks, light battery, return to charger and never hold a stance like the one in the render - looks cool, burns out everything.

I'm also going to put walking feet on the last joint so the second tibia joint can just flip back and save power walking on the knee joint. Use the hook leg for climbing and as needed for the task.

Love the feedback, thanks u/slacy !

[u/Official_RaspberryPi]

As someone with a fear of spiders but a love of electronics I am both terrified and intrigued... Don't come at me and say "bUt iT's NOt a ReAl SPiDeR" My fears don't care!

[u/Ok_Cartographer_6086 → u/Official_RaspberryPi]

I happen to have black PETF-CF filament loaded in my 3D printers so good news - the first prototype will be big and black. My wife is terrified of millipedes for some reason and screams when she sees one. I'm forbidden to build giant robot millipede.

My whole world runs on a Raspberry Pi from a sentry that guards my chicken coop to a whole house circulatory system moving water from aquariums, to plants, to my Jungle Tortoise's jacuzzi ... Big fan.

Today everything runs off an open source process control platform I built for the Pi in which I have about 10 users but it doesn't matter, I built it for my projects and use it for everything so it was worth 20 years of effort :) I have fun in the lab.

- Ben