add default values for support

src/Mechanical/Rotational/sources.jl

@@ -1,6 +1,6 @@
 @mtkmodel PartialTorque begin
     @parameters begin
-        use_support
+        use_support = false
     end
     @extend flange, phi_support = partial_element = PartialElementaryOneFlangeAndSupport2(use_support = use_support)
     @variables begin
@@ -34,7 +34,7 @@ Input signal acting as external torque on a flange
 """
 @mtkmodel Torque begin
     @parameters begin
-        use_support
+        use_support = false
     end
     @extend (flange,) = partial_element = PartialElementaryOneFlangeAndSupport2(use_support = use_support)
     @components begin
@@ -69,7 +69,7 @@ Constant torque source
         [
             description = "Constant torque (if negative, torque is acting as load in positive direction of rotation)",
         ]
-        use_support
+        use_support = false
     end
     @extend flange, phi = partial_element = PartialTorque(; use_support = use_support)
     @variables begin

test/Mechanical/rotational.jl

@@ -62,6 +62,7 @@ end
     J_motor = 0.1 # Motor inertia
 
     @named fixed = Fixed()
+    @named torque_test = Torque() # Test that it's possible to instantiate torque with default support value
     @named torque = Torque(use_support = true)
     @named inertia1 = Inertia(J = 2, phi = pi / 2)
     @named spring = Rotational.Spring(c = 1e4)