How to add the stator back iron parameter with the Adaptive Template in MotorCAD?

This guide explains how to control stator back iron thickness using Adaptive Templates in Motor-CAD. The method uses an Adaptive Parameter to update the slot depth automatically while keeping the stator outer diameter fixed. The geometry refresh is f

Preparing the Adaptive Parameters

Open Geometry → Editor → Adaptive Parameters and create the following entries: 

Stator Back IronThk

This is the value you change from the Radial tab. It represents the radial distance you want between the slot top and the stator OD. 

Last_Back_Iron_Thk

A helper parameter required to stop the Adaptive Template from running repeatedly. 

Set its initial value to 0. 

Understanding the Geometry Relationship

Since the stator OD remains fixed, the only way to change the back iron thickness is by adjusting the slot depth. 

Definitions: 

Stator outer radius = Stator_Lam_Dia / 2 
Stator inner radius = Stator_Bore / 2 
Slot top radius = Stator inner radius + Slot_Depth 
Back iron thickness = Stator outer radius − Slot top radius 

Rearranging gives the slot depth needed: 

Slot_Depth = Stator outer radius − Stator inner radius − Back Iron Thk 

This formula ensures the radial distance from the slot tip to the outer lamination always matches your chosen back iron thickness. 

 

Creating the Adaptive Template Script

Navigate to: 

Geometry → Editor → Adaptive Templates 

Set Geometry Templates Type = Adaptive, then paste the script: 

import ansys.motorcad.core as pymotorcad 

mc = pymotorcad.MotorCAD(open_new_instance=False) 

back_iron_thk = mc.get_adaptive_parameter_value("Stator Back Iron Thk") 

last_value = mc.get_adaptive_parameter_value("Last_Back_Iron_Thk") 

if back_iron_thk == last_value: 

raise SystemExit 

mc.set_adaptive_parameter_value("Last_Back_Iron_Thk", back_iron_thk) 

mc.reset_adaptive_geometry() 

stator_outer_diam = mc.get_variable("Stator_Lam_Dia") 

stator_inner_diam = mc.get_variable("Stator_Bore") 

stator_outer_radius = 0.5 * stator_outer_diam 

stator_inner_radius = 0.5 * stator_inner_diam 

slot_depth = stator_outer_radius - stator_inner_radius - back_iron_thk 

mc.set_variable("Slot_Depth", slot_depth) 

mc.display_screen("scripting") 

mc.display_screen("radial") 

What the script does 

Detects whether the backiron parameter changed 
Stops immediately if nothing changed (prevents infinite loops) 
Recalculates slot depth using the required formula 
Applies the new slot depth through scripting 
Forces geometry refresh by flipping screens 

Workflow to Use the Parameter
Go to Geometry → Radial. 
Change the value of Stator Back Iron Thk. 
MotorCAD triggers the Adaptive Template script. 
Slot depth updates in the background. 
Geometry redraws automatically due to the screenswitching commands. 
Your back iron thickness is updated. 

Note: The text field for Slot Depth in the Radial tab may not immediately show the new value, but the geometry and internal model do update.