[V] AutoCAD 实战讲座第七讲( T. J* P+ Q( e8 T
AutoCAD 实战讲座第七讲) {/ B( f2 ]: t* n2 O
New Maple AutoCAD (7)& M) j7 N/ d# W n www.newmaple.com/video/autocad00071 G- E* f% z C% G1 o: y. M" f
* Z& L G( K+ [. J4 f, j3 dA real sample to review lecture 6 # M! j* v) O1 t- [* Z2 a) R) ] % |2 X: d. j7 b+ b" s% AIntroduction Roughness' r8 d d5 w# H: z5 \! K8 X% R
Quick check hole size and position ) K) ?8 e* {8 M+ I1 [/ xIntroduction O-ring groove9 c! p3 p+ r1 b# A* K' \
% C4 D0 k7 Y* T/ ]1 hSurface roughness 1 ^9 K; }8 R8 u8 l x- a4 t8 Q• Imperial Unit: micro-inch 10-6 inch 4 D7 J( q) M4 s z X• Metric Unit: micrometer 10-6 m( J+ @" u9 C& n
• Sample 250 micro-inch = 6.3 micrometer , @4 h' P3 N9 S3 d# r: l(250X25.4X10-3)# D- O- A4 l6 X
• 250 micro-inch – forging surface5 I% X9 a! t: |0 \* W& b
• 125 rough machine, 32 fine machine + s& j" E7 J9 w' H* T5 c1 w ! G$ {: H) R$ q! ^' C& ?: _3 SInch size O-ring3 Q# {4 b& p7 f5 N% ]* T5 \9 t
• O-ring number 2323 T G5 t6 ]: _" a. T, C+ Q4 p
• nominal size 2.75”x3”x1/8” 1 _ K k' \- G6 C• Actual size 2.734”x3.012”x0.139” 2 b) r' ^9 g5 Y0 a• Static surface seal groove depth 0.101~0.107 about 25% squeeze1 s i: L( C; q9 B0 k
• One of OD or ID is close standard size( t9 {3 B5 e8 a( ?. W @ H* ~