Rotate a model and parent children around center of model

Hi guys; I want to be able to rotate a model around the center of its self. I have this script but it rotates the model around an axis and not the center of the model. Can anyone help me. Thanks

function onClicked()
    rotation=true parts=game.Workspace.Clay_Paky_K20_Beye.Pan:GetChildren() 
	for i=1,#parts do if parts[i]:IsA("Part") then 
		parts[i].CFrame=parts[i].CFrame + Vector3.new(0,0,0) 
		if rotation==true then 
			parts[i].CFrame=CFrame.Angles(0,0.01,0) * parts[i].CFrame 
			else 
		end 
	end 
	end

	
	
end
 
script.Parent.MouseButton1Down:connect(onClicked)

function Transform(model, center, new)
	for _,v in pairs(model:GetChildren())do
		if v:IsA("BasePart")then
			v.CFrame=new*center:inverse()*v.CFrame
		end
		Transform(v,center,new)
	end
end

This will transform model by the difference between center and new, new being the new rotation.