HOME HANDICRAFT 335
Space will not allow us to go into details as a thorough description would be quite lengthy. Go to a near-by public library and get a book on casting and pattern making. You will have to make your pattern of wood first. Split it, as you cannot make the mold from it otherwise. Now dowel the two parts together; make yourself a flask from wood; get some molding-sand, read your reference carefully and try making a mold. When you have cast a good one, drill a hole in center to receive your crank shaft G, which is made from 0.25" brass rod flattened and bent on one end as you will note in drawing G. D is also made of 0.25" brass rod flattened and drilled on both ends. This is your piston-rod and is fastened so that it will work freely to your piston-head J, which is best made of iron turned to size on a machine lathe.
The eccentric B also should be made of iron on a lathe. This should have a small hole drilled in the shoulder and tapped to receive a set screw P, so that it can be firmly fastened to crank shaft. This eccentric, as you will notice from the drawing, is hung off center, which, when fastened firmly to shaft, transmits a slight motion to B, which, when fastened to eccentric ring C, fits in the groove of the eccentric and continues the motion by way of the sheet metal triangular piece M to the valve rod F. The valve is made similar to the piston-head except in size. This is fastened to the end of F and through its motion regulates the intake of steam which enters through hose connection at N. A small block of wood is put under one corner of M to raise it to the level of your valve and center of the crank-shaft. Two bearings are made from sheet brass about 0.125 inch thick with a hole drilled near top to receive crank-shaft freely and holes near the bottom for screws to fasten to side of base.
If you should have any trouble in making your engine run, look to your valve and see if you have it adjusted so that the valve-hole is clear to receive the steam pressure at the beginning of the outward stroke, and if it is cut off at the completion of the stroke and return of the piston head. Proper