Ctrl+K

Crane node

Crane node#

The crane super-node makes it easy to model and control cranes.

To add a crane to the model

  • Select “add crane”

  • In the “path” property of the node: select the crane type.

A crane has a parent, position and orientation. This defines where the bottom center of the crane is.

image-20231030165428032

The node models:

  • a crane that can optionally revolve (slew)

  • a boom with one of more points at which hooks can be attached

  • optionally a jib

  • optionally an extension (for telescopic cranes)

Cranes modeled using this node do not have tie-back wires. They are not intended to be used for situations where the forces in those wires are of importance.

  • The angle of the boom can be controlled directly or by setting a reach or radius for one of the hooks

  • Setting slew to “auto” releases the slewing brake meaning that the crane is free to slew.

Hooks#

Hooks are separate nodes. They can be added to the crane using the “add hoist” button. Hooks are separate nodes such that it is possible to use them without a crane.

To set hook height or elevation, select the hook node.

Defining new crane types#

Cranes can be added using .crane.csv files in a resources folder. For the structure of a .csv file see CSV format

Schematically the crane node looks as follows:

image-20230425153753945

The crane model does not include the hooks themselves, only the locations where a hoist can be added.

The hooks that can be attached contain the suspension wires as well as the hook itself. The elevation of the hooks can be set in the hook node.

The boom is divided into two parts:

  • BoomBase : the part of the boom attached to the boom hinge

  • Boom : the part of the boom that is extended if extension > 0

Similarly the crane itself is split into:

  • CraneBase: the part of the crane that is fixed

  • Crane: the part of the crane that slews

Non-functional crane wires can be added for visual pleasure using BeatyLines.

Example .csv file#

An example of a crane (without weights) is given below.

# This is an example of a crane
#
boom_hinge_x	 4
boom_hinge_z	 8
# --- JIB (optional)
#
jib_hinge_x	 42  # relative to boom
jib_hinge_z	 0   # relative to boom
#
*BoomPoints
# name	  x  	 y 	 z
main	    35 	 0 	 -2
aux	     40 	 0 	 -1

#
#
*JibPoints
# name 	 x	 y	 z
jib    	 15	 0 	 -1

#
# ---- Boom Extension
#
extension_max	 20 # remove this line to prohibit extension
#
# ---- Weights and visuals (all optional)
#
# For extending crane booms: BoomBase is the part of the boom
# that is connected to the crane hinge.
# Boom is the part that shifts away from the hinge when extended
#
# Visuals are:
# Name 	 	resource	 	off-x	 off-y	 off-z	 rot-x	 rot-y	 rot-z	 scale-x	 scale-y	 scale-z

*CraneVisuals
slew_ring	res: cube.obj	 0	0	7	   0	0	0	    8	8	4
*CraneBaseVisuals
mast	 	res: cylinder 1x1x1.obj	 0	0	0	   0	0	0	    4	4	40

*BoomVisuals
boom_ext	res: wirecube.obj	 20	0	0	   0	0	0	    20	 2	 1

*BoomBaseVisuals
boom_base	res: cube.obj	 5	0	0	   0	0	0	    10	 3.5	 1.6

*JibVisuals
boom_jib	res: wirecube.obj	 7.5	0	0	   0	0	0	    7.5	 2	 1

*CraneWeights
*CraneBaseWeights
*BoomWeights
*BoomBaseWeights
*JibWeights

*BeautyLines
# Beauty Lines are lines that are added just for visual pleasure
# From [Base, Slew, Boom, Jib]
# To   [Base, Slew, Boom, Jib]
# from  x1	y1	z1	TO      x2	y2	z2
Base	0	0	40	Boom	38	0	1
Contents