How do I make the part stick to the player's arm?

I've been trying for over a week to figure this out, I tried dozens of methods and none of them work. Right now I managed to make the part shoot out of my arm properly when I stand still, however when I move around it won't stick to the arm.

ReplicatedStorage.RemoteEvent.OnServerEvent:Connect(function(player)
    local righthand = player.Character.RightHand
    local humanoidroot = player.Character.HumanoidRootPart
        wait(0.5)
        local Beam = ServerStorage.BeamPart:Clone()
        Beam.Parent = game.Workspace
        Beam.Anchored = true
        Beam.CFrame = righthand.CFrame + humanoidroot.CFrame.lookVector * 1.5
        Beam.Parent = game.Workspace
        Beam.BrickColor = BrickColor.new("Bright orange")
        Beam.Size = Vector3.new(3,3,3)
        Beam.Material = Enum.Material.Neon
        Beam.CanCollide = false
        Beam.Massless = true
        Beam.Transparency = 0
        local weld = Instance.new("Weld")
        for i = 1,10 do
            wait()
            Beam.Transparency = Beam.Transparency + 0.1
            Beam.Size = Beam.Size + Vector3.new(0,1,0)
            Beam.CFrame = Beam.CFrame + humanoidroot.CFrame.lookVector * 0.5
        end
end)