Advanced Toy Making for Schools Part 5

[Ill.u.s.tration: Fig. 19. Wheel cutter in use]

A saw board, as shown in Fig. 21 should be fastened to a table top with an iron clamp; or, a saw board made to fasten in a vise may also be used.

[Ill.u.s.tration: Fig. 20. Details of a wheel cutter which may be made in school]

When cutting out the toy part, the coping saw should be held in a vertical position as shown in Fig. 22, and in an up-and-down motion, with short fast strokes, following the outline carefully. Cut on the line. Do not press hard on the saw for the blade is very thin and can very easily be broken, but it should last a long time if used correctly.

[Ill.u.s.tration: Fig. 21. Clamping the saw board to the bench]

[Ill.u.s.tration: Fig. 22. Correct method of holding coping saw]

#48. Cutting Sharp Corners.#--When cutting a sharp turn in the wood with the coping saw, care should be taken not to twist the saw blade out of shape. Upon reaching the sharp turn, continue the up-and-down motion, but without doing any cutting; turn the wood very slowly until you have made the complete turn, then continue with the sawing and follow the rest of the outline carefully.

[Ill.u.s.tration: Fig. 23. Removing the saw-blade]

#49. Removing the Saw-Blade from Frame.#--To remove the saw-blade from the frame, place the head of the frame against the table top as shown in Fig. 23. Pressing down on the handle will release the saw-blade. When inserting the blade into the frame the same method may be followed, being careful that the teeth of the saw-blade point toward the handle of the frame. The blade may be put in the end or the side slots of the frame, using the side slots only when the end slots will not serve the purpose.

#50. Making Heavy Wheels.#--In turning heavier wheels that are to be used for coasters, kiddie cars, etc., the work is done with the head stock only, the wood being supported by the screw-center chuck or face plate.

In turning the wheel the first step is the sc.r.a.ping cut as shown in Fig.

24. This cut is properly made with the concave chisel held in such a position as to give a light sc.r.a.ping cut. Care should be exercised not to allow the chisel to extend too deeply, otherwise the material will chip with the grain.

After the desired circ.u.mference has been obtained the surface should be worked to the desired form as shown in Fig. 25. This is accomplished by using the lathe rest, set at right angles with the bed or parallel with the face plate. The ill.u.s.tration in Fig. 26 shows the use of the dividers in marking off the position of the various corrugations in the wheel that is being turned. The sanding should be done while the wheel is in the lathe. Use first a fairly course grade of sand paper and afterwards a fine grade, No. O or OO.

#51. Designs for Wheels.#--Suggestions for wooden toy wheels are shown in Fig. 27. Those numbered 1, 2, 3, 4, 5, 6, and 7 are plain wooden wheels varying in design only. No. 8 and 9 are re-enforced with zinc and large iron washers. No. 10 shows a segment of an iron pipe fitted in the center of the wheel to prevent wearing away of material. No. 11 shows a spoke wheel. The spokes are made of dowel rods; these fitting into a hub that can easily be turned out on the lathe. No. 13 shows a wheel built in segments which is then cut out on the band saw to resemble a standard spoke wheel. The rim is 1/8" steel, fastened to spokes with very small rivets.

[Ill.u.s.tration: Fig. 24. Making heavy wheels. The sc.r.a.ping cut]

#52. Cutting Wheels on Band-Saw.#--A circle of the required size wheel may be marked off on the wood with a compa.s.s, then cut in the outline on the band-saw. This method will leave square corners and will be more or less out of truth with the center of the wheel. To true up and smooth the outside of the wheel the lathe attachment as shown in Fig. 28 can be easily prepared. This attachment consists of a block _A_ fastened to the lathe bed with a single bolt, and a stop _B_ fastened to the upper face of the block _A_. The carriage _C_ is a loose piece the same thickness as the stop _B_ and is provided with a dowel rod to fit the central hole in the wheel. This dowel rod is so located that when the edge of the carriage _C_ is tight against the edge of the stop _D_, the distance from the center of the dowel rod to the face of the abrasive material on the disk, will be equal to the radius of the finished wheel.

[Ill.u.s.tration: Fig. 25. Smoothing the side of wheels]

The wood is cut out on the band saw a scant 1/16" over-size in diameter, and is then placed on the dowel rod in the carriage _C_ which is held flat on block _A_ while the edge of the blank is brought in contact with the grinding disc face by pus.h.i.+ng the carriage forward with the left hand while the blank is slowly revolved with the right. This grinding is continued until the edges of stop _B_ and carriage _C_ will remain in contact during a complete revolution of the wheel blank. During this grinding process, the carriage should be moved back and forth from the edge to the center of the grinding disc so that the wear on the abrasive material may be equalized.

[Ill.u.s.tration: Fig. 26. Using dividers to mark for cuts]

A similar device used for chamfering the edges of the blanks is also shown in Fig. 28, as it looks when viewed from the front of the lathe.

The preceding description will suffice for this as the same system of lettering has been used. It differs only in that block _A_ is made to set at an angle of 45 degrees instead of being level.

[Ill.u.s.tration: Fig. 27. Many ways of making wheels for toys]

[Ill.u.s.tration: Fig. 28. Simple attachments which may be made for lathe]

Grinding discs may be made either of metal or wood. Metal is preferable but a hardwood disc fastened to a metal face plate will answer very well. There are many methods of fastening the abrasing material to the disc but the most convenient way is by the use of stick belt dressing.

The disc is coated with dressing by holding the stick against it as it revolves and the abrasive is applied before the dressing has set. A pair of dividers or trammels is used to cut the abrasive material to the same diameter as the disc and it should be warmed on the uncoated side before it is applied. It sticks tightly to the disc but is easily removed and replaced with fresh material in a few minutes.

#53. Boring Holes in Wheels.#--The center holes in wheels may be bored with bit and brace, but better results are obtained if the holes are bored in the lathe. A drill chuck fitted to the live spindle and a drilling pad for the tail stock spindle will be required to do this job efficiently. The tail stock is locked fast and the wheel to be drilled is placed against the drilling pad and fed up to the revolving bit by turning the tail spindle feed wheel. This method will produce a cleaner hole and one that is square with the wheel face.

CHAPTER V

OPERATION OF WOODWORKING MACHINES

#54. Importance of Machine Operations.#--A fair understanding of what is the correct position to take at some of the princ.i.p.al machines such as the lathe, universal saw, jointer, and sander, is very important to the student in the wood-working department. Such knowledge is of special importance to the one engaged in toy making, where every knowledge of use of machines, is put to the test.

[Ill.u.s.tration: Fig. 29. The roughing cut]

[Ill.u.s.tration: Fig. 30. The sizing cut]

Sufficient examples are given to enable the student to arrive at a fair understanding of the correct postures.

#55. Operating the Lathe.#--The lathe is perhaps one of the most important machines used in toy making. It lends itself to unlimited varieties of work and for that reason is really indispensible in the shop.

[Ill.u.s.tration: Fig. 31. The paring cut]

In Fig. 29 the student is preparing to take the _roughing cut_ in turning a cylinder. This operation consists of removing the corners of the square piece and is done with the tool known as the _gouge_.

After the roughing cut has been taken, calipers set to the diameter desired will determine the depth of the next cut, _sizing cut_. The ill.u.s.tration in Fig. 30 shows the student performing this operation with the _cut-off tool_.

[Ill.u.s.tration: Fig. 32. Using the cut-off tool]

When the correct dimension has been found, the next step in the process of turning a cylinder is the _paring cut_ or finis.h.i.+ng cut, Fig. 31.

This is done with the _skew_ or _bevel chisel_. A very thin shaving is removed by this operation.

The ends are then cut by using the cut-off tool as shown in Fig. 32. It is merely taking a slice off the end. If a very thin slice is to be removed, it is usually made by the long point of the skew chisel. If it is more than a quarter of an inch it should be _sized_ and then removed by the skew.

[Ill.u.s.tration: Fig. 33. Making convex surfaces]

If it is desired to round the end of a piece or to produce a convex surface the operation can be done by applying the broad side of the skew chisel, as in Fig. 33.

#56. Face Plate Turning.#--The preceding paragraphs describe the process of turning when the piece is supported between the live and the dead centers. The processes shown in Figs. 24, 25 and 26, ill.u.s.trate the character of the work done with the head stock only when the piece is supported by the screw-center chuck or face plate.

[Ill.u.s.tration: Fig. 34. Polis.h.i.+ng wood in lathe]

The first step in face plate turning is the sc.r.a.ping cut, Fig. 24. This cut is properly made with the concave chisel held in such a position as to give a light sc.r.a.ping cut. Care should be exercised not to allow the chisel to extend too deeply, otherwise the material will chip with the grain. After the desired circ.u.mference has been obtained the surface should be smoothed with the skew chisel.

[Ill.u.s.tration: Fig. 35. Cutting off stock]

[Ill.u.s.tration: Fig. 36. Fluting on circular saw]

Fig. 25 shows the student modeling a rosette, using the rest, set at right angles with the bed or parallel with the face plate. Prior to the modeling a shearing cut should be taken with the skew chisel to face off the material to an even surface.

[Ill.u.s.tration: Fig. 37. Cutting with special fence]

The ill.u.s.tration in Fig. 26 shows the use of the dividers. The student is marking off to a uniform scale the position of the various corrugations in the rosette he is turning.