# Mobile Home Robot — LONG-TERM concept

The end goal: a full home robot that drives around and manipulates. Two flavors on the table:
1. **Standard mobile manipulator** — 4-wheel base + a vertical linear rail (lift) + an arm at the end
   (maybe the arm we are building now, or a manual/simple one).
2. **Access-gantry on a mobile base** — the 3-axis gantry (docs/gantry) shrunk onto a wheeled base, so the
   whole XYZ workspace rides around the house. More interesting / more reach-in capability (fetch-like).

## How it builds on what we have
- Reuses the **arm** (short-term print) as the manipulator, and/or the **gantry** (mid-term) as the XYZ stage.
- The **vertical linear rail** is the shared hard part — same lessons as docs/gantry (self-locking leadscrew
  for the lift, so the arm does not drop when power is off).

## Open questions (for later)
- Base: differential drive (2 driven + casters) vs 4-wheel (mecanum for omni?).
- Lift height + payload → motor + leadscrew sizing.
- Power: onboard battery, one bus for base + lift + arm.
- Sensing: the Arducam wrist cam + a base lidar/depth cam for navigation.

_Not started — captured so the short/mid-term designs stay compatible with it._

## v1 built (see mobile_base.urdf)
4-wheel chassis + vertical 2040 lift mast (prismatic 0-650mm) + 4-DOF forward arm. gen_mobile.py. Next: gantry-on-base variant, or printable arm-mount + real diff-drive. Reuses the vertical-leadscrew lesson from docs/gantry (self-locking lift).

## Lift drive: use a self-locking T8 leadscrew (NOT a belt) so the arm holds its height when power is off — same reasoning as the gantry vertical axis (docs/gantry/IMPLEMENTATION_GUIDE.md). BOM: docs/home_robot/BILL_OF_MATERIALS.md.