Grandpa wrote...

Speaking of large chessmen, is there a standard correlation between the
size of the squares on a board and the footprint or height of the men -
excluding the obvious? I'd like to make a larger board, maybe 3' across.

Four pawns should just barely fit on a single square.

There are no hard and fast standard base and height relationships for the

rest of the pieces, but there are some conventions that work well.

A pawn is usually about 15% taller than its base. The king is usually
about twice the height of the pawn. The other pieces are generally sized
to fit "smoothly" between the king and pawn: king, queen, bishop, rook,
knight, pawn.

The Staunton design and minor variations of it dominate the chess scene.
A standard competition chessboard square is 2-1/4".

Here are some notes I took when making my set:

Traditional Staunton set
Bases - inches (units)
==================================
P - 1.19" (0.53 times standard square size)
R - 1.24" (1.04 times pawn base)
N - 1.31" (1.10 times pawn base)
B - 1.25" (1.05 times pawn base)
Q - 1.50" (1.26 times pawn base)
K - 1.55" (1.30 times pawn base)

Heights - inches (units)
==================================
P - 1.85" (1.55 times pawn base)
R - 2.10" (1.14 times pawn height)
N - 2.30" (1.24 times pawn height)
B - 2.65" (1.43 times pawn height)
Q - 3.30" (1.78 times pawn height)
K - 3.70" (2.00 times pawn height)

The dimensions of the popular "Ultimate" chess pieces give some
perspective:

Ultimate Staunton set
Bases - inches (units)
==================================
P - 1.18" (0.52 times square size)
R - 1.31" (1.11 times pawn base)
N - 1.34" (1.14 times pawn base)
B - 1.39" (1.18 times pawn base)
Q - 1.45" (1.23 times pawn base)
K - 1.57" (1.33 times pawn base)

Heights - inches (units)
==================================
P - 1.84" (1.56 times pawn base)
R - 2.10" (1.14 times pawn height)
N - 2.34" (1.27 times pawn height)
B - 2.65" (1.44 times pawn height)
Q - 3.00" (1.63 times pawn height)
K - 3.53" (1.92 times pawn height)

In some of the "oversize" chess sets I've seen, the variations between
the sizes of the pieces is not so pronounced. The king might be only 1.5
times the height of a pawn.

Jim