Metal Spinning tools can be placed in three classes: blunt tools, beading tools, and cutting tools.The average beginner’s set should include the following: (1) flat tool; (2) diamond point cutting-off tool; (3) point tool; (4) planning tool; and (5) beading tool.
There are many other tools used by professional spinners in production work, but very satisfactory results can be obtained with the tools just mentioned.
THE FLAT TOOL OF Spinning
In metal spinning, the fiat tool is used more than any of the others. One portion of the tip is flat for smoothing purposes and the opposite side is flat for breaking down and spinning to the chuck. The portion where the flat joins the round is also rounded, but to a sharper radius, so that this edge can be used to bear into sharply rounded fillets. The flat is practically the only one needed , for forming and finishing soft metals, such as pewter and aluminum.
THE DIAMOND POINT TOOL .
The diamond point is used to trim excess metal from the lip of the spun object and for rounding off sharp edges.
THE POINT TOOL
The point tool is used for bearing into curves of small radii, with both concave and convex surfaces.
THE BEADING TOOL
The beading tool is used for turning the edge of a spun bowl to a beaded lip. It can also be used for grooving shallow decorative motifs around bowls. In the ordinary beading tool the rolls are interchangeable. The beading wheel can vary from 1 to 2 in. in diameter.
THE FINISHING TOOL
It is necessary to have a finishing tool to remove any marks that might be left from any of the other tools. For this purpose, the planishing tool is commonly used. The edge of the tool at its end may also be used to make small grooves or shoulders in the shell.
The backstick is another necessary tool. It can be made from a broom handle and tapered at the end like a chisel. Its chief function is to provide pressure behind the spinning tool in the breaking-down process. It can also be used to prevent wrinkling of the metal at the edges.
THE SPINNER’S CENTER
A spinner’s center can be made from an ordinary tail center by purchasing two bearing races and one thrust bearing. Place one thrust between two bearing races and slip them over the dead center.
Excellent spinner’s centers can be purchased from commercial companies specializing in their manufacture. These centers are very dependable and can be used for an indefinite period of time.
THE Principle of SPINNING REST In Metal Spinning Tools
The principle of the spinning rest is practically the same as that of a wood lathe tool rest except that vertical holes are bored into it at intervals for holding a steel pin which acts as a fulcrum for the tool. A very good rest can be purchased for about two dollars.
The average mechanic can easily construct a spinning rest if he has a drill press heavy enough to do the required drilling. A very good idea of the construction of one of these rests.
The chuck may be described as the form over which the spinning is done. Chucks may be turned from either wood or metal. Wooden ones may be made easily by anyone having a small amount of knowledge of wood turning. If they are to be used repeatedly, it is best to make them of hardwood. Birch, maple, gum, or walnut are very satisfactory. If soft materials are used, they must be resurfaced frequently. Maple probably is the best of the woods, and may be used many times without resurfacing.
Chucks may be glued from 2-in. circular blanks. They may be fastened to the faceplate with screws or threaded to fit the lathe spindle. A tap may be purchased to thread the chuck, or a hole may be bored in the chuck in. smaller than the lathe spindle which may serve as a tap. The chuck may then be turned to any desired shape and sanded smooth.
It is almost impossible to spin some forms without first making a breakdown chuck . Projects with tall, straight sides, like the creamer shown in Figure 57, require considerable skill in spinning in order to avoid spoiling the metal. The pressure of the tool places a strain on the metal at the base, causing it to tear at this point if the pressure is too great, or applied for too long a time. This may be avoided by the use of a breakdown chuck, which permits the spinner to change the point of strain. The chuck for the project should be made first and the base of the breakdown chuck should match the regular chuck.
The follow block , generally made of wood, is a fixture used to hold the metal blank against the chuck. It must revolve freely and at the same speed as the chuck. Any slippage will either bum the wood or the metal.
The follow block should be at least 1 in. thick and never larger that the diameter of the base to be spun. If it is too small, there is danger that the metal may be spun back over the block. If the block is too large, it is difficult to work in close to the base.
A hole should be bored in the center of the block to fit the friction unit of the center. Do not bore all of the way through the block as the resulting hole will leave a mark on the soft metal.
Instead of turning the follow block on a screw-center faceplate, center it right behind the wood chuck, and bring up the tailstock center and turn it to size. The face of the follow block should be turned to fit the base of the object being spun.
The friction set up while spinning makes it necessary to use a lubricant on the surface of the metal while it is being spun. This lubricant prevents the tearing of the metal.
As an effective lubricant for pewter, copper, and aluminum cup grease or laundry soap can be used. Tallow candles make an excellent lubricant for hard metal. A very good lubricant for pewter and copper can be made by dissolving a half cake of laundry soap in \y2 pt. of water. After this mixture has been dissolved add 1 pt. of No. 30 lubricating oil and stir thoroughly. After it has stood for 12 hrs. it will be ready for use. The lubricant may be applied with a brush or any other dauber, such as a piece of cloth wrapped around a stick.
Pewter, copper, and aluminum are the three most common metals used by the beginner in spinning.Pewter has been long used for household purposes. First produced by the Romans, its popularity and manufacture increased until, in the Middle Ages, it was practically the only metal used by the upper and middle classes. Thereafter the introduction of earthenware and china brought pewter into disuse, and, at the end of the eighteenth century, it had been entirely supplanted by other materials. The twentieth century, however, brought forth renewed interest in pewter among metal craftsmen.
Pewter is an alloy, which during the ages, has been changed in composition to a remarkable degree. It is generally considered to be an alloy of 80 per cent tin and 20 per cent lead. In France pewter for drinking vessels or food containers is restricted by law to a maximum of 18 per cent lead to avoid lead poisoning. In England the lead content is restricted to about 10 per cent.
In America manufacturers of pewter have excluded the lead entirely which is responsible for the popularity of pewter articles in this country. This lead-free pewter does not turn dark gray as the pewter containing lead. It is sometimes called Britannia metal.
Britannia metal is of English origin dating back to the year 1780. The composition of this metal is 91 per cent tin, 7per cent antimony, and V/2 per cent copper. The antimony and copper is added to harden and stiffen the tin.
Pewter lends itself perfectly to the beginner’s purposes because it spins so easily, does not harden during spinning, and, therefore, does not have to be annealed.
Copper is very popular among students and craftsmen because it is not quite as expensive as pewter. It is slightly more difficult to spin than pewter as it becomes hard and springy from the pressure and must be annealed frequently. Copper may be annealed by heating it to an iridescent color and then plunging it into cold water. This metal works up beautifully and takes a brilliant polish, which has to be lacquered to prevent tarnishing.Aluminum is very easy to spin, having many of the desirable qualities of pewter. It is harder than pewter yet spins easily and takes a very high polish.