Many parts will be cut from pieces of ready cut strip or drawn
wire, but some things, like mainframes, boilers, or cab fronts
and sides will have to come out of sheet metal. Most, but not
everything following, will apply to other materials, the
exception being plasticard. To enable one to cut shapes from
metal, the shape must first be draw or marked out on the metal.
This is not difficult to do provided one follows some simple
rules. 1 From the original drawings do a sketch, complete with
dimensions of the section(s) that are to be marked out, then
check that you've transferred the dimensions correctly. This
drawing does not have to be an exact machine drawing, but all
the important lines and dimensions must be included. 2 Where
possible all the dimensions should be measured and drawn from
two lines drawn at right angles to each other called datum
lines. These lines are usually drawn at the bottom and on the
left hand side. If for example you are marking out a main frame,
the most important lengths will be th