brim.core.attachment.Hub

class brim.core.attachment.Hub(frame: ReferenceFrame, point: Point, axis: str | Vector)

Bases: Attachment

Joint attachment for pin joints.

Explanation

This class is used to define the attachment points of pin joints. It extends brim.core.attachment.Attachment by specifying an additional rotation axis property.

Attributes

axis	Rotation axis of the hub.
frame	Reference frame of the attachment.
point	Point of the attachment.

Methods

__init__
from_name	Create a hub based on a name and an axis.
to_valid_joint_arg	Convert the attachment to a massless body.

__init__(frame: ReferenceFrame, point: Point, axis: str | Vector) → None

__weakref__

list of weak references to the object (if defined)

property axis: Vector

Rotation axis of the hub.

property frame: ReferenceFrame

Reference frame of the attachment.

classmethod from_name(name: str, axis: str) → Hub

Create a hub based on a name and an axis.

property point: Point

Point of the attachment.

to_valid_joint_arg(name: str | None = None) → MasslessBody

Convert the attachment to a massless body.

Explanation

This method is used to convert an attachment to a massless body. This is necessary because sympy’s joints framework does not yet support passing only a frame and point to the joint constructor. Therefore, this method may be removed once this functionality is added to sympy.