What are specific applications for the following pattern: materials wood, metal
and ... (Herbert J. Mccaslin, Wood Patternmaking A Textbook, Macgraw-Hill Book
...
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EF*7 &'D52 ( ,-ก Pattern 1. Shrinkage allowance (,*:''(./05('ก5 ) 2. Machining allowance (,*:''(./05('กก36D,ก) 3. Allowance for draf (,*:''(./07ก2D:กP57 ) Questions 1. Distinguish between liquid shrinkage and solid shrinkage as related to casting. 2. Explain how these are taken care of in designing sand casting. 3. What is draft allowance? How is it provided for pattern? 4. What is the meaning of core prints? Explain how they are provided. 5. What are specific applications for the following pattern: materials wood, metal and plastic? 6. Why is a loose piece pattern used? Give its problems. 431310 กก (Foundry Laboratory)
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(Pattern) )97 896 (Pattern) /&+0(+'กก * ก,* %'P367 &+0&9(&:*5:686 5'(H/0 :*5(.0%(%12:3M* (./07ก2ก5 7(H/0กก36 /D,ก (./012D52M*,*&+0%+:*5% 26ก;' 68กก ก&97 8968 5( A*6*: M*(0%7ก:66* g3068268 5&9:3M*%ก*8กM*,*86K /8ก Drawing 5 6* M*ก&97 896836%+)%,9) h%1*2' ก&+08D52 M*6*)-J;.5+ก&96*6',5ก ,M*( /6766*1*ก&97 *2' 826ก7 767H*i+ก&97 125+52' 1*ก(/ก ,5-,9 7 896* M* 826.8JP36 E88 '6 K 5 6*+M 1. 89**M*6*&+026ก 2. ,5-1*ก&97 &+0812 3. ก4Jก%i+1*ก&97 4. )%*:6M*6* 5. )%(+' :6H 7)%7***:6:*5M*6* ,5-&+012&97 896%+%ก%''*512(/ก :3M*'Oก E88 '6K 5 6&+0ก% ,5-&+0*'% 12&97 896%ก&+0,-5D527ก D%2 (.D%2( A* ,5-&+0D526' )D%,O6(ก*D ( A* ,5-&+0%+*M9* ก( (*/M* ,%P 5(8 7: 512H(+' D52,5ก 1* 6กJ+812,+ 7(7)&D526' 7D%2กj%+ :2(,+'6&+0'-ก126*8, M* (%/0POก(,+'5,+ก &'7 (()(:'*5367 896ก8ก &'7 887ก/ กD52 *ก8ก*+M' ก 56/( +0'*O &6D526' (%/0 %J)%/M*1*(*/MD%2 ( +0 ' *7 6 , 5- ,%P*9 %12 &9 7 89 6D52 ( %/ *ก * )%)6&*P5+ ก D%2 % ก *ก8ก*+M' 6D%5O5)%/M*8ก&'7 &+012,*1hD527ก (jก &6(/6 *gk 7 O%(*+'%H,% .,ก ( A* ,5-+ก*5*306&+0(0%%+)%,9) h1*ก&97 896 ,*1h( A*.ก Thermosetting (* Phenolic rasin, Foam plastic ,(k g306( A*HH8ก ' g 0% ,%P/
EF*( A*7 896D526' ก 76กj&9D526' *5:67 896 7 6% ก4J:67 D52' (;& 5 6D *+M 1. 7 M*(5+' (One piece or Solid) 2. 7 ,6M*/7 7'ก,6M* (Two piece or Split) 3. 7 Loose pattern (,*&+0( A* Loos piece 85'Oก &'7 ก* (%/0(P5(7 ,* 1hก72 8(ก5&+06.12(,%PP5 Loos piece ก8ก7 &'D52) 4. 7 Match Plate 5. 7 Follow Board 6. 7 Gate Pattern 431310 กก (Foundry Laboratory)
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Patterns and Related designs Wood pattern
Fig. 1. Patternmaker working to close shape tolerances, carving the wood pattern of a special core plate pattern. Metal pattern
Fig. 2. Aluminum alloy patterns and core boxes are frequently suitable for shell molding. (Al-7%Cu-5%Si-0.15%Ti) Patternmaker constructing an aluminum core box. Critical area of the core box is being machined with the use of a special cutter in a drill-press head. (J.Gerin sylvia, Cast Metals Technology, p. 16 and 30)
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$ OP 1. One piece or Solid Pattern Disposable patterns &+0&98ก ,5-89.ก stryrofoam / polystryrene
Fig. 3. Top, disposable pattern Bottom, a 9930 lb (4469 kg) casting. (B.H. Amstead, Phillip F. Ostwald and Myron L. Begreman, Manufacturing processes, seventh edition, p. 104)
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$ OP 2. Match Plate Patterns
Fig. 4. Match plate patterns
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$ OP 3. Loose pattern 7 896 6) M68%+ ก4J&+0ก12(ก5 Eh1*กP57 8ก&' 836D%8&97 896 ( A*7 M*(5+'/ ,6M*D52 5'(p.7 &+0&9%-%(+'65 67,561*;. (./012กP57 D52,5ก 836 5 (J&+0( A*%-%(p+'6ก 7&9( A*M**3066ก(./012-5D52,5ก*P57 ,*&+0( A* Loose piece 85'Oก &'7 ก* (%/0(P5(7 ,*1hก72 8(ก5&+06.12( ,%PP5 Loose piece ก8ก7 &'D52)
Fig. 5. Alternate methods of making gib-block patterns. A, Gib block. B, Construction of pattern with loose pieces and green-sand core. C, Construction of pattern using dry-sand core. D, method of molding with loose pieces. E, Method of molding using dry-sand core. (B.H. Amstead, Phillip F. Ostwald and Myron L. Begreman, Manufacturing processes, seventh edition, p. 104) 431310 กก (Foundry Laboratory)
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$ OP 4. Pattern Construction.
The drawing of a brass guide.
Sectional view of the drag part of the mold for the guide.
One half of the core for the guide and the core box in which it is formed. The pattern for the guide.
The parts of the core box for guide dressed to shape and ready to be attached together. Fig. 6. (Herbert J. Mccaslin, Wood Patternmaking A Textbook, Macgraw-Hill Book Company, Inc, 1941, p.91 t96) 431310 กก (Foundry Laboratory)
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$ OP 5. Pattern Construction.
The drawing of a cast-iron piston.
The core box for the pistion pattern in course of assembling., The Forstner bit.
The pattern for the pistion showing the arreangement of the core print. Fig. 7. (Herbert J. Mccaslin, Wood Patternmaking A Textbook, Macgraw-Hill Book Company, Inc, 1941, p. 256-258) 431310 กก (Foundry Laboratory)
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