Practical Carriage Building
Compiled by M.T. Richardson, Vol.1. 1891
Carriage and Wagon Wheel Making in Country Shops Part 3
Fig. 133 represents a spoke pointer. In this machine the knife is held by two screws, and cuts a much longer taper than the old-style pointer. The adjustable shank should be set at a figure on its scale corresponding to the required size of the tenon. It will then leave the spoke the exact size required to receive the hollow auger. I omit just now any further description of tools or ma-chines, but shall take occasion to refer now and then, in the course of this article, to a number of other exceedingly meritorious machines, wherever my text may make such ref¬erence desirable.
My purpose at present is to describe the manufacture of hubs and tires. I first measure carefully inside the tire, having thoroughly cleaned it. I next measure the diameter of the hub by means of the calipers, and also take the depth, height, and width of the mortise in the hub.
I take notes of these measurements as follows: For ex-ample, the tire may measure one hundred and eighty-eight and a half; then add one-half for draw and note one hundred and eighty-nine. The hub may measure ten inches in diameter, the mortise three inches, height two and a half inches, width one and a quarter inches. Measure the height of the felloes (two and a half inches as wide as the tire.) To find the length of the spokes from hub to felloes, first find the exact diameter of the wheel by dividing the periphery by twenty-two and multiplying the result with seven. Example: One hundred and eighty-nine, divided by twenty-two, multiplied by seven, equals sixty and three-twenty-seconds, or one-eighth as the nearest convenient fraction. Deduct from this total the diameter of the hub and double the height of the felloes, thus ten, add two multiplied by two and a half, equals fifteen, equals forty-five and one eighth; divide by two equals twenty-two and nine-sixteenths; add one-sixteenth for draw, and say twenty-two and five-eighths inches for the length of the spokes from hub to felloes (in¬side). For the tenon in the hub, add two and three-quarter inches, depth three, less one-quarter inch. For the tenon in the felloes, add two and three-quarter inches. (This is the height of the felloes—two and a half inches, plus one-quarter inch.) The whole length of the spokes should be twenty-eight and one-eighth.
To find the distance of spoke tenons in felloes from each other, deduct from the periphery of the wheel (one h undred and eighty-nine) twice the height of felloes, multiplied by three and one-seventh. Thus, two multiplied by two and a half equals five multiplied by three and one-seventh—fifteen and five-sevenths; and one hundred and eighty-nine, less fifteen and five-sevenths, equals one hundred and seventy-three and two-sevenths. Now divide this sum by the number of mortises in the hub, fourteen, equals twelve and three-eighths.
Having found all necessary measures, put the hub over the bolt; push up the bolt, slip the dish gauge over the bolt, and screw it down tight. Take a straight edge, insert it in a mortise in the hub and keep it in place by a small wedge. Measure the distance from straight edge to the dish gauge. Take off one-half or three-quarters of an inch, or as much as you want to give dish, and drive out a one-half inch pin, corresponding with length of spoke to measure by. Take a pencil and mark outside of and very close to the hub on the straight edge, which bevel transfer to a bevel gauge. Remove the straight edge and prepare every spoke ready for driving. The lower tenon should measure one-quarter of an inch less than the depth. To the height of the tenon add one-sixteenth of an inch, and the width exact measure. With the calipers find the measure inside of the mortise, close to the box. Before driving mix dry red lead and varnish; smear some on every tenon, and drive with rather a heavy hammer, with steady, well-aimed strokes, taking care to push the pin in the gauge from time to time over the spoke, to find in which direction it will go. Diversions from the right direction can be remedied by inserting a stout lever under or over the spoke, and using the next spoke as a fulcrum, to pry the spoke so it can be driven in the right direction.