# Sliding Sleeve

*A telescoping column joint, drawn parked*

**Names:** `sliding_sleeve`

## When to use

Use `sliding_sleeve` for a telescoping member: an inner post riding in a bored outer sleeve
(a music-stand column, an adjustable leg), drawn **parked** at one declared height. It is a
static pose, not a `travel`: nothing is swept (ADR-0075 does not apply) and each part keeps
one transform. Keywords: telescope, sleeve, column, adjustable height, slip joint.

## Syntax

```kdl grammar
joinery sliding_sleeve name=<Name> {
    extension <mm>     // required: how far the inner member stands out of the mouth
    clearance <mm>     // the bore is this much wider than the member (total, ADR-0012)
    depth     <mm>     // optional: a blind bore; absent or 0.0 bores the whole sleeve
}
join joint=<Name> male=<Inner>@<Foot> female=<Sleeve>@<Mouth>
```

- `Foot` is a mark on the inner member's inserted end face, `Mouth` one on the sleeve's open
  end face, each normal pointing out of its own wood: they face each other.
- The author places both parts; the joint **checks** the pose: the foot is on the mouth's axis
  (`sleeve-axis`), and the member is placed so it stands exactly `extension` out
  (`sleeve-pose`). `sleeve-extension`: nothing of the member is inside. `sleeve-depth`: the
  bore is shorter than the engagement or the sleeve. `sleeve-fit`: no wall is left.
- The bore is the member's section plus `clearance`, so the member stands in air and there is
  no clash to exempt; a mis-posed member still clashes and is reported.
- Both members stay in the cut list. The join gap check skips it (a clearance fit).

## Pitfalls and diagnostics

- `extension` is declared and the placement is yours: change `stand_height` and the inner
  member's length and `pos` together, or `sleeve-pose` says they disagree.
- The inner member's section is read off its `Foot` face; a member turned a non-right angle
  about the column's axis against the sleeve is not synthesised (`sleeve-axis`, unsupported).
- A blind bore leaves wood at the sleeve's foot (`remaining-wall` warns when thin).

## Example

`examples/music_stand.kdl`: `ColumnSleeve` on the spider, `ColumnInner` parked
`stand_height - sleeve_len` out, carrying the head.

## See also

- [`travel`](travel.md) — a swept motion; this joint is a parked pose.
- [`hardware-mounting`](hardware-mounting.md) — the clamp knob, as a round proxy.
- [`tongue-and-groove`](tongue-and-groove.md) — another one-off joinery kind's page.

## Names

Every name this page declares, how the example library uses it, and the shortest real use.

### `sliding_sleeve`

joinery kind; value in 1 of 116 examples (1 uses).

Shortest real use, from `music_stand.kdl`:

```kdl
joinery sliding_sleeve name=Telescope {
    extension column_extension
    clearance glue_clearance
    depth     bore_depth
}
```

## Related terms

- [Sliding sleeve](/almanac/techniques#sliding-sleeve)