---
name: "lineardeltakins"
section: "9"
platform: "linux"
package: "linuxcnc-uspace"
version: "1:2.9.4-2+deb13u1"
release: "Debian 13 (Trixie)"
platforms: ["linux"]
url: "https://new.carta.tech/lineardeltakins"
---

# lineardeltakins(9)

Kinematics for a linear delta robot

## NAME

lineardeltakins - Kinematics for a linear delta robot

## SYNOPSIS

**loadrt lineardeltakins**

## KINEMATICS

The kinematics model is appropriate for a rostock/kossel-style design with three joints arranged in an equilateral triangle. (0,0) is always the center of the working volume. Joint 0 is at (0,R) and subsequent joints are 120 degrees clockwise (note that joint 0 is not at zero radians). The length of the arm is L.

Joints 0-2 are the linear carriages. Axes ABC and UVW are passed through unchanged in joints 3-8, so that e.g., A can still be used to control an extruder.

## PINS

- **lineardeltakins.R float in**

  Effective diameter of the platform.

  R is different than the distance from the center of the table to the center of the belt/smooth rod/extrusion that the joints ride on. In RepRap delta parlance, R is DELTA\_RADIUS which is computed as

  DELTA\_SMOOTH\_ROD\_OFFSET - DELTA\_EFFECTOR\_OFFSET - DELTA\_CARRIAGE\_OFFSET.

- **lineardeltakins.L float in**

  Length of the rod connecting the carriage to the effector. In RepRap delta parlance, L is DELTA\_DIAGONAL\_ROD.

## NOTES

The R and L values can be adjusted while LinuxCNC is running. However, doing so while in coordinated mode will lead to a step change in joint position, which generally will trigger a following error if in joint mode with machine on.