Arms of dummy falls off, Why?

I have a script where it makes a dummy. But its arms keep falling off for some reason Heres the code

function makedummy(makejointoption)

    local dummy = Instance.new("Model",workspace)
    local larm = Instance.new("Part",dummy)
    local rarm = Instance.new("Part",dummy)
    local lleg = Instance.new("Part",dummy)
    local rleg = Instance.new("Part",dummy)
    local head = Instance.new("Part",dummy)
    local torso =Instance.new("Part",dummy)
    local rootpart =Instance.new("Part",dummy)
    local humanoid = Instance.new("Humanoid",dummy)



local generalsize = Vector3.new(1,2,1)
larm.Size = generalsize
rarm.Size = generalsize
rleg.Size = generalsize
lleg.Size = generalsize
torso.Size = Vector3.new(2,2,1)
rootpart.Size = Vector3.new(2,2,1)
    head.Size = Vector3.new(2,1,1)
    dummy.PrimaryPart = rootpart

    rarm.Position = Vector3.new(1.5,5,0)
    rleg.Position = Vector3.new(0.5, 3, 0)
    lleg.Position = Vector3.new(-0.5, 3, 0)
    larm.Position = Vector3.new(-1.5,5,0)
    head.Position = Vector3.new(0, 6.5, 0)
    torso.Position = Vector3.new(0,5,0)
    rootpart.CFrame = torso.CFrame
    local rootweld = Instance.new("Weld",rootpart)
    rootweld.Part0 = torso
    rootweld.Part1 = rootpart
    rootweld.C1 = torso.CFrame
    --naming the donkey who doesn't hear well
    larm.Name = "Left Arm"
    lleg.Name= "Left Leg"
    rleg.Name= "Right Leg"
    rarm.Name= "Right Arm"
    head.Name= "Head"
    torso.Name= "Torso"
    rootpart.Name= "HumanoidRootPart"
    humanoid.MaxHealth = math.huge
    humanoid.Health = math.huge
 rootpart.Anchored = true
    torso.Anchored = true
if makejointoption == true then
        dummy:MakeJoints()
    else
        print ("Dummy has no joints")
    end
end
makedummy(true)

I tried :MakeJoints on the dummy model but still nothing worked.