FORMERS FOR COILS

Radio Record, Volume I, Issue 4, 12 August 1927, Page 14

FORMERS FOR COILS

It is, not always possible to purchase the particular size or diameter of coil former required, so here is given a simple aud handy method of making a neat, true, and serviceable former of any exact dimensions. A sixteenth of an inch is usually sufficient thickness for the wall of an ordinary former. ‘I'wo layers of the white card called by printers ‘8-sheet" will make up this thickness. If thinner card is used sufficient layers must be put on to make up one-sixteenth. ‘Ihe method will be best described by taking some particular size as an example, so we will Suppose it is desired to make a former of three inches outside diameter and four inches long. From an old cardboard box cut six circles Qin. diameter and pile them up with small blocks of wood or anything handy to separate them about 3 inch as shown at

A im accompanying drawing. This is only to act as a core around which to make the former. Now cut a strip of the good card four inches ,wide and place round core, marking where it mects, and cut just short of mecting round. Now keeping this round the core, place another strip round the outside, marking the full distance round, and cutting off just short. Now glue about half of cach together as shown at B, and when the glue is sufficiently set, glue all over portion marked X, place round core, work into position with both hands, w ind two or Uirce yards of twine round outside and leave to set. Seccotine used sparingly is a handy adhesive. A- coat of thin shellac varnish will keep the damp out.