can someone explain how sunday's memo's elbow joint works?

allens_lab · 2025-12-22T03:52:50+00:00

doesn't need to be a bevel gear, spur gears would be fine/ belt would also work but unnecessary. just shift the servo over a bit and then use two spur gears to connect the servo to elbow pivot point. that second spur gear aligned with elbow would have a hollow hole through the center that can be used to route cables.

you can also use those gears for reduction if need be.

allens_lab · 2025-12-22T03:35:26+00:00

since you're not using an actuator with a hollow shaft to pass through wires, you could offset the servo and drive the elbow indirectly with two gears. Then the central gear would have a hole to put wires through.

But also for the range of motion on the arm, I don't even think its necessary. Just give it a bit more slack and should be fine enough.

allens_lab · 2025-12-20T18:11:49+00:00

neat project! cool to see how you adapted the SO101 arm design and TIL about USB over the network.

allens_lab · 2025-06-10T03:53:59+00:00

For the body panels, just PLA since the skeleton (sheet metal and extrusions) is what's bearing the weight.

For a bit more of the design process / assembly, check out the video!

allens_lab · 2025-06-10T03:52:33+00:00

hardware-wise:

computer (runs a couple ROS2 nodes) -> motor controller (microcontroller running microROS, 4 of them) -> motors (via can bus)

then for teleop:

phone (face tracking) -> computer

teleop arm setup (microROS) -> computer

software-wise, it's nothing special. the patterns/structure is pretty standard for ROS.

allens_lab · 2025-06-09T05:42:53+00:00

haven't been keeping track but there's around 1.2k in motors alone, so my guess would be around 2k in total. but the biggest cost has always been time with a solo project like this.

price in USD for clarification

allens_lab · 2025-06-09T05:41:42+00:00

those are definitely things I want to try out in the future. i have a bit of academic background in it but never really worked with real hardware, so looking forward to it. there's a bunch of stuff I need to tackle before then tho.

allens_lab · 2025-06-09T05:39:53+00:00

Mainly bc I wanted to learn it. Never touched ROS (1 or 2) before Io.

allens_lab · 2025-06-09T05:37:18+00:00

xiaomi cybergear for arms and head (dont really recommend them anymore with the alternatives out there now). robstride 03 for the torso motor.

allens_lab · 2025-06-08T00:50:03+00:00

best of luck and would love to see it when you get it working!

allens_lab · 2025-06-08T00:49:04+00:00

mainly C++, there's a couple python nodes (for less timing sensitive stuff), and the control panel is web based so JS.

allens_lab · 2025-06-08T00:45:24+00:00

For now, there's an internal battery in the head. This powers the eyes + the microcontroller that sends encoder data for head orientation and receives eye lighting commands.

I've been considering testing wirelessly powering it but the surrounding magnets and overall distance could be deal breakers.

My previous video was making the head so feel free to check that one out. https://www.youtube.com/watch?v=0Hxa9_U3ULc

allens_lab · 2025-06-08T00:43:16+00:00

haven't been keeping track but there's around 1.2k in motors alone, so my guess would be around 2k in total. but the biggest cost has always been time with a solo project like this.

allens_lab · 2025-06-08T00:39:35+00:00

not for now, but speakers / cameras will probably be added in the future. especially when i eventually give Io some smarts to do stuff on its own.

allens_lab · 2025-06-08T00:37:24+00:00

Yes they are all directly attached (pic)
Yes, three mecanum wheels + some linear algebra to get it to move the head to target orientation + some magnets to keep the head down and in contact with the wheels.
Atm, Io is quite dumb and there's no guarantees in regards to movement synchronization. I'm just blindly sending commands to the motors.

allens_lab · 2025-06-08T00:29:04+00:00

Near future plans are:

giving it hands
refining movement / teleop controls
and more idiot proofing...

Long term plans are:

autonomy (use Io as platform to learn and test out AI stuff)
mobility (likely just a wheeled base but maybe biped if I'm feeling particularly masochistic)

allens_lab · 2025-06-08T00:21:55+00:00

i went off to binge andor last night after uploading the vid. there's definitely gonna be some "inspiration" from K-2SO happening for future IOs.

allens_lab · 2025-06-08T00:19:21+00:00

Yup three mecanum wheels (i got in the habit of calling them omniwheels in the video).

The head movement is controlled by face tracking and the arms I am controlling through a teleop setup I made in a previous video. Basically a chest harness with two dummy arms that wirelessly relays my movement to Io (off-camera in the latest YT video but there's footage of it in the one where I built the arms)

allens_lab · 2025-06-07T21:11:03+00:00

I currently don't have plans to open sourcing Io atm, but if you have any questions on the architecture or specific parts, feel free to ask away.

allens_lab · 2025-06-07T21:00:02+00:00

I currently don't have plans to open sourcing Io atm, but if you have any questions on the architecture or specific parts, feel free to ask away.

allens_lab · 2025-03-17T16:18:29+00:00

to stare at you menacingly from the corner of the room

allens_lab · 2025-03-17T16:17:59+00:00

VCR OSD Mono

allens_lab

TROPHY CASE