3. Why should plenty of oil be used on an oil-stone?
4. Explain with sketch the method used in casting a small hollow cylinder.
5. For what parts of the pattern must the shrinkage rule be used?
6. Is the draft always the same on all parts of a pattern?
7. What is the usual allowance for finish on small castings?
8. When must a greater amount be allowed?
9. Under what conditions will a seasoned board warp?
10. What wood is most commonly used in pattern making?
11. Explain the difference in the manner in which saws cut when ripping and when crosscutting.
13. When is dry parting sand used?
14. Should a shrinkage rule be used when making a core box?
15. Why must the pattern maker know something of Mechanical Drawing?
16. When it is necessary to use a wide piece for a pattern, how may the tendency to warp be counteracted? Make sketch.
19. What is meant by shrinkage in pattern making?
20. How are the exact proportions of shrinkage obtained for different parts of the pattern?
21a. What is the usual proportion of draft to each twelve inches of surface on the face of a pattern for a cast-iron pulley?
21b. What proportions on the inside of the rim and on the hub?
22. When is it necessary to use mahogany, cherry, or maple for patterns?
23. What is lead in a plane-iron, and what determines the amount?
24. Explain the use of a flask in moulding, and describe the two principal parts.
25. What allowance must be made on the pattern for shrinkage when the casting is made of iron?
26. Explain what is meant by draft in pattern making?
27. How should lumber for patterns be seasoned?
28. When a large piece is to be used for turning, should it be cut from a plank of the required thickness or glued up out of thinner stock? Give reasons for answers.
29. Explain the methods of grinding the brad-awl and the advantages of each method.
30. Explain the use of core prints.
31. What is the allowance for shrinkage of brass? 32. What are the usual allowances for draft?
33. What is meant by finish in pattern making?
34. When gluing up pattern stock, how is the pressure necessary to bring the glued surfaces in close contact usually obtained?
1. What are rapping plates?
2. Describe the process of gluing two thin pieces having large surfaces.
3. How is end wood treated if it is to be glued to other wood?
4. Explain why the upper core print sometimes has excessive draft, while the lower has but little draft.
5. What are fillets, and where are they used on patterns?
7. The pulley mentioned in Question 6 is to be fitted to a shaft 2 9/16 inches in diameter, (a) What should be the diameter of the hub? (b) What should be the length of hub?
8. What is a follow board, and when is its use necessary?
9. A pair of tight and loose pulleys 12 inches in diameter and 6) inches wide of face, are to be fitted to a 1 11/16-inch shaft. (a) Give diameter of the hub. (b) Give length of hub.
10. What must be the outside diameter of the original wooden pattern for the rim of a pulley with six arms, the diameter of the finished pulley to be 30 inches and the width of face 9 inches?
11. (a) In the above pulley what should be the width and thickness of the arms at the rim? (b) What should be the width and thickness of the arms at the hub?
12. What are core prints and when do they form a necessary part of a pattern?
13. How are the two parts of a parted pattern held together for turning? Give two methods.
14. What are the proportions of alcohol and shellac gum for pattern maker's shellac varnish?
15. Is it always necessary to make a pattern in two parts?
16. How is colored shellac varnish made? (a) How is black made? (b) How red?
17. Give a sketch, including all dimensions, of the pattern for a plain brass cylinder which is to be finished "all over", the finished sizes being 6 inches long, 4 inches outside diameter, and 3 1/2 inches inside diameter. All shrinkage rule measurements, allow 3/32 inch for finish.
18. What is a core box, and for what purpose is it used?
19. What is used to give a hard, smooth surface to a completed pattern?
20. What color should be used for the inside of a core box?
21. How can the pattern for a small hollow cylinder be molded if made in one piece (not parted)?
22. Why are core prints shellacked in a different color from the body of the pattern?
23. What are dowel pins, and why are they used in a parted pattern?
24. How long a time should each coat of shellac have for drying before another coat is applied?
25. Give sketch showing shape and dimensions of core box for pattern mentioned in Question 17.
26. It is required to make the pattern for a five-arm 15-inch hand-wheel, the rim and hub of which are to be turned and finished. The finished diameter of the round rim is to be 1 5/8 inches, and of hub 2\ inches. Allowing 1/16 inch for finish, give all dimensions for the wooden pattern, including width and thickness of arms at the rim and at the hub.
27. Give a sketch and all dimensions (shrinkage rule measurements) of the pattern for a cast-iron cylinder having a projecting flange, on each end (see Fig. 149), the cylinder to be bored out and finished all over, the finished sizes being as follows: Length 8 inches, diameter of flanges 5 1/2 inches, thickness of flanges 3/8 inch, the diameter of the body of the cylinder outside 4 inches, and inside 3 1/4 inches, allowing 1/8 inch for finish.'
28. Can the above pattern be molded without being parted?
1. What allowance should be made for expansion in a dry-sand core?
3. What is a radial gage?
4. Discuss the use of the parallel drawing device.
5. Where should identification marks be placed, and why should these not occur on the ends of the draw plate?
6. Discuss the use of the pattern board, giving a concrete example.
7. What are the allowances for shrinkage in the construction of a wooden pattern of a shaft hanger bearing cap?
9. Discuss machine molding, giving its advantages and disadvantages.
10. Sketch a radial sectional view of a pattern for a flange coupling.
11. Give a complete description of the method used in making a spur-gear pattern.
12. Discuss the correct method of stock preparation.
13. When using the drag machine how many molds can be made at one operation?
14. When using the drag machine, why cannot the pattern be bolted directly to the draw plate?
15. Discuss the use of a vibrator.
16. When and why are trial castings made?
17. What is an expanding pattern and when is it used?
18. Discuss the use of the double-draw stripping-plate machine.
19. Give the correct method for forming pattern for a short length of cast-iron pipe 6 inches inside diameter.
20. Discuss the preservation of master pattern.