Equilateral sets in the l1 sum of Euclidean spaces

Let En denote the (real) n-dimensional Euclidean space. It is not known whether an equilateral set in the 1 sum of Ea and Eb, denoted here as Ea. 1 Eb, has maximum size at least dim( Ea. 1 Eb) + 1 = a + b + 1 for all pairs of a and b. We show, via some explicit constructions of equilateral sets, that this holds for all a 27, as well as some other instances.