Knife to hand weld not working, can anyone fix it?

I am making a 1v1 knife fight game that uses welds instead of tools can somebody help

Note : The game uses R6 rigs

game.Players.PlayerAdded:Connect(function(Player) -- Player
    Player.CharacterAdded:Connect(function(Char) -- Character
        local Head = Char["Right Arm"] -- Character's Body Part
        local Part = game.Workspace.Handle -- Directory To Part To Weld
        local Weld = Instance.new('Weld', Head)
        Part.Position = Head.Position +Vector3.new(0.039,-0.769,-1.009)
        Weld.Part1 = Part
        Weld.Part0 = Head
end)
end) 

Just know i may have gotten the Vector3 values wrong

Right Arm Position : -26, 3, -21

Knife Position : -25.961, 2.231, -22.009