  We present the design, construction, and simulation of a simple, low-cost
external cavity diode laser with a measured free-running frequency drift rate
of 1.4(1)~MHz/h at 852 nm. This performance is achieved via a compact, nearly
monolithic aluminum structure to minimize temperature gradients across the
laser cavity. We present thermal finite element method simulations which
quantify the effects of temperature gradients, and suggest that the drift rate
is likely limited by laser-diode aging.
