It now remains only to provide a fly-wheel and treadle with the communicating belt. The fly-wheel may be of any convenient size, or it may be some discarded pulley or wheel. Suppose it is two feet in diameter; then, as your small pulley is 2 inches in diameter, each revolution of the large wheel makes twelve revolutions in the mandrel, and you can readily turn the wheel eighty times a minute. In that case your mandrel will revolve 960 revolutions per minute, which is ample speed for
our purposes.

The wheel should be mounted on a piece of ¾-inch steel tubing, one end having a crank 3 inches long. This crank is connected up by a pitman rod, with the triangularly shaped treadle frame.

Such a lathe is easily made, as it requires but little metal or machine work, and it is here described because it will be a pleasure for a boy to make such a useful tool. What he needs is the proper plan and the right dimensions to carry out the work, and his own ingenuity will make the modifications suitable to his purpose.

The illustration (Fig. 245) shows such a lathe assembled ready for work.