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hardware

Every article tagged hardware, newest first.

Precise control of the SO-101 arm · Part 5 of 8 · HardwareOctober 5, 202624 min read

Design 5 on the full arm in a drawing pose

A pen holder that shows the arm’s error, not its own

I want to see my SO-101 trajectory errors as ink on paper. For that, the pen must not add an error of its own. I made five holder designs. The one I release is a printed sleeve that slides onto the stock gripper: 4 printed parts, nothing to buy, any pen from 8 to 13 mm.

Precise control of the SO-101 arm · Part 1 of 8October 2, 202644 min read

Three drawings of one joint as a torsion spring. With no load, the goal and the joint sit on the target. With gravity and the goal on the target, the joint sags below and the spring between goal and joint stretches. With the goal moved up past the target, the stretched spring holds the joint on the target.

One equation, and every way the arm misses it

Start from torque = inertia × acceleration, then add each term a cheap servo arm really has: gravity, friction, a payload, dead time, a dead band. Each term is one way the arm misses its target.

so-101 control hardware

September 26, 202617 min read

Franka arm with human-readable joint names and colored rotation arrows

How an arm moves: joints, geometry, and motor control

From encoder readings to gripper position: a visual guide to robot geometry, servos, and the commands that connect them.

control hardware sensors

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