You can’t set the properties of a Vector3. They’re read-only. You would have to create a new Vector3 to apply a change to the position like that. Here’s a quick code-sample demonstrating how you might do that:
local changeofvelocity = Vector3.new(0, 1, 0)
wait(5)
local part = game.Workspace.Part
while true do
part.Position = part.Position + changeofvelocity
wait(3)
end
I believe, and anyone correct me if I’m wrong, but you can not individually change the x,y,z of any part by themselves by the way you are doing. You could just do part.Position = part.Position + Vector3.new(0, changeofvelocity, 0)