Motion system
=============

Purpose
-------

- Provide precise, repeatable axis motion
- Keep motion execution simple and robust in the initial build
- Allow future upgrades without redesigning the machine structure

Current motion configuration
----------------------------

- Motion controller:

  - Duet 3 6HC
- Motors:

  - stepper motors on all linear axes
- Motor drive:

  - steppers driven directly by Duet
- Mechanical transmission:

  - HTD belt between motor and leadscrew
- Purpose of belt coupling:

  - mechanical filtering of motor vibration
  - increased effective steps per millimeter
  - flexibility in gear ratio selection
- Leadscrews:

  - directly coupled to axis motion
- Feedback:

  - open-loop stepper operation in current phase

Design considerations
---------------------

- Motion system prioritized for:

  - simplicity
  - predictability
  - compatibility with supervision layer
- Motion execution kept independent from:

  - adaptive supervision logic
  - compliance estimation
- Any feed or spindle adaptation performed via:

  - Duet macros
  - supervisory requests only

Deferred motion upgrades
------------------------

- Closed-loop servo drives
- Dual-loop control using external feedback
- Glass scale integration
- Custom servo inverter development

Scope limitations
-----------------

- No real-time modification of trajectories by ECU
- No active damping or compensation within motion controller
- Motion system behavior assumed deterministic for supervision purposes