why does c1 cframe isnt on the position? help me1

local floorplank2 = Instance.new("Part",workspace)

local player = game:GetService("Players").LocalPlayer
local weld = Instance.new("Weld",floorplank2)
weld.Part0 = player.Character.Torso

weld.Part1 = floorplank2
floorplank2.BrickColor = BrickColor.new("Brick yellow")
floorplank2.Orientation = Vector3.new(-90, 0, 0)
floorplank2.Anchored = true
weld.C1 = CFrame.new( Vector3.new( 0 , 0 , 10 ) )
weld.C0 = CFrame.new() -- default