I know how to send raycasts and use ignore lists, but I don’t know how to find the vector to send the raycast in that direction relative to the part’s orientation
You take the parts position (origin) and add a downwards vector
local partPosition = part.Position
local RAYCAST_DOWN_VECTOR3 = Vector3.new(0, -50, 0)
raycastResult = workspace:Raycast(partPosition, RAYCAST_DOWN_VECTOR3)
if raycastResult then
...
end