How to scale a CQ-Object

[Paul8043]

How to scale a CQ-Object without changing the dimension of the box? I am looking for the counterpart of OpenSCAD scale([xy,z]). I have searched in the online-manual, but could not find a solution there. This is a functionality needed very often, e.g. when printing a shrunk prototype with a 3D-printer.

# HowTo: scale a CQ-object, looking for the counterpart of OpenSCAD scale([x,y,Z])

import cadquery as cq

result = cq.Workplane().box(100,100,100).scale(0.1)            # same factor for all axis
# or 
result = cq.Workplane().box(100,100,100).scale((0.2,0.1,0.5))  # individual factor for each axis

# show_object(result,name="result",options={"alpha":0.2,"color":(255,170,0)})

[Paul8043]

There exists a scale(factor) for Shapes. But I need this for a Workplane-Object. Please help.

[jmwright]

You can call scale on the wrapped object and it will be as if you called it on the Workplane itself.

import cadquery as cq

box = cq.Workplane().box(10, 10, 10)
cylinder = cq.Workplane().center(10, 10).cylinder(10, 5)

box = box.val().scale(0.1)

show_object(box)
show_object(cylinder)

[Paul8043]

@jmwright
Thanks for this tip. I will use scale() for making small 3D-prototypes with a printer. OpenSCAD-porters would appreciate the second form, where each axis can be scaled down individually. This might seem to be an unusual use-case, but this is not the complete truth. Most often the second form is used to perform mirroring e.g. scale([1,-1,1]) would mirror on y-axis like mirrorY().

[jmwright]

Potentially related issues on anisotropic scaling.

#638

#1026

#225 (that was before the switch to OCP)