Engineering 312 Engineering Graphics Assignment 14 Engineering Tolerance and more Hand Sketching Fall 2020 Tolerance CAD systems use exact mathematical measurements (numbers). But in reality, it is impossible to manufacture a part to these exact dimensions. Instead, for critical applications, we must specify a range of values that a given dimension must fall between. The difference between the largest and smallest acceptable values of a dimension is called the "tolerance". A tolerance can also be thought of as a "range" of acceptable values that a dimension must be between. Tolerance is critical for parts that must fit together precisely! There are many kinds of tolerances for various purposes. The textbook has lots of details. For this assignment we will focus on the 1) basic idea, 2) tolerance stacking, and 3) clearance and interference fits. Shaft clearance and interference fits Rotating machinery uses shafts, bearings and other parts which typically require tolerances. The most common types of fits for shafts are clearance fits (the shaft can slide or turn) and interference fits (the shaft cannot be moved without significant force). Deliverables: Use a pencil to hand sketch each of the following entire figures with all the parts and dimensions as shown. Redraw the chart by hand, then calculate and fill in the required information. Break up the charts and put each figure on one piece of paper. Make each figure big enough that it fills the paper in portrait orientation. You should draw 12 drawings on 12 pieces of paper. There are occasional errors in these drawings from the textbook. Figure out what makes the most sense and fix them. Copyright © 2020 Dan Ross Page 1 of 3 228 PART 1 Basic Drawing and Design LIMITS AND TOLERANCES LIMITS AND TOLERANCES LIMITS AND TOLERANCES A +.00 3.50 F -.02 +.00 3.00 1.25±0.3 1.00+.01 -.03 E G B-.00 2.00 ±.02 XXX XXX + + XXX C -XXX- -2.250 ±.001 0.750 J +.000 -.001 0.240.001 2 HOLES D COMPLETE THIS CHART FROM THE INFORMATION GIVEN ABOVE K- L 3.44 ±.06 2.38 ±.01 M 1.75 ±.01 75.01 R 十囧 N+.00 1.00-.02 .502 +- 0 .498 COMPLETE THIS CHART FROM THE INFORMATION GIVEN ABOVE A B C D E F G BASIC SIZE BASIC SIZE TOLERANCE LIMITS MAX OF SIZE TOLERANCE LIMITS MAX OF SIZE MIN MIN Fig. 8-110 Inch limits and tolerances. XX H XXX P 0.320 +.001 -.000 3 HOLES COMPLETE THIS CHART FROM THE INFORMATION GIVEN ABOVE J K L M BASIC SIZE TOLERANCE LIMITS MAX OF SIZE MIN N LIMITS AND TOLERANCES LIMITS AND TOLERANCES LIMITS AND TOLERANCES A 0 90 -0.5 +0.3 E 0 B XX 32±0.125 XX 95 C 60±0.02 + 06±0.02 2 HOLES COMPLETE THIS CHART FROM THE INFORMATION GIVEN ABOVE F 0 -75 -0.76 50 ±0.5 XX © 20 0 -0.02 K- 20±0.25- 十囧 NT O 25-0.05 12.50 0 12.46 COMPLETE THIS CHART FROM THE INFORMATION GIVEN ABOVE M L 90 ±1.5 70±0.25 50 ±0.25- -+- R XX 010 +0.02 0 3 HOLES COMPLETE THIS CHART FROM THE INFORMATION GIVEN ABOVE P R A B C D E F G H J K L M N P R BASIC SIZE BASIC SIZE BASIC SIZE TOLERANCE LIMITS MAX OF SIZE TOLERANCE TOLERANCE LIMITS MAX OF SIZE MIN LIMITS MAX OF SIZE MIN MIN Fig. 8-111 Metric limits and tolerances. Copyright 2020 Dan Ross Page 2 of 3 230 PART 1 Basic Drawing and Design .7492 CO .7484 CLEARANCE FITS INTERFERENCE FITS CLEARANCE AND INTERFERENCE FITS XX ØK 0.7500 ±.0020- E 1.5018 1.5024 .9997 1.0005 0 0 .9993 1.0000 1.5010 F 1.5000 ЧА B XX -ØJ .7512 DO XX .7500 GI.2500 +.0010 -.0000 H 1.2475 1.2469 XX COMPLETE THIS CHART FROM THE INFORMATION GIVEN ABOVE TOLERANCE ON HOLE TOLERANCE ON SHAFT MINIMUM CLEARANCE MAXIMUM CLEARANCE Fig. 8-114 Inch fits. A B C D CLEARANCE FITS COMPLETE THIS CHART FROM THE INFORMATION GIVEN ABOVE TOLERANCE ON PART TOLERANCE ON SLOT MINIMUM INTERFERENCE MAXIMUM INTERFERENCE E F INTERFERENCE FITS G H 0 1.2510 1.2500 QI. DIMENSION SHAFT (J) TO HAVE A TOLERANCE OF .0012 AND A MINIMUM CLEARANCE OF .0025. Q2. DIMENSION BUSHING (K) TO HAVE A TOLERANCE OF .0010 AND A MAXIMUM INTERFERENCE OF .0016. Q3. DIMENSION SHAFT (J) TO HAVE ATOLERANCE OF.0012 AND A MINIMUM CLEARANCE OF .0014. Q4. DIMENSION BUSHING (K) TO HAVE A TOLERANCE OF .0008 AND A MAXIMUM INTERFERENCE OF .0022. COMPLETE THIS CHART FROM THE INFORMATION GIVEN ABOVE ΟΙ Q2 Q3 Q4 J K CLEARANCE AND INTERFERENCE FITS XX OK 19.05 ±0.02 44.96 E 44.70 0 25.40 25.35 25.47 0 25.42 44.45 F 44.20 A B XX ØJ DØ19 +0.02 0 0 CO19 0.05 COMPLETE THIS CHART FROM THE INFORMATION GIVEN ABOVE TOLERANCE ON HOLE TOLERANCE ON SHAFT MINIMUM CLEARANCE MAXIMUM CLEARANCE Fig. 8-115 Metric fits. A B C D Copyright 2020 Dan Ross XX G 32±0.12 H-31.75 0 -0.12 XX COMPLETE THIS CHART FROM THE INFORMATION GIVEN ABOVE TOLERANCE ON PART TOLERANCE ON SLOT MINIMUM INTERFERENCE MAXIMUM INTERFERENCE 31.75 0 31.62 QI. DIMENSION SHAFT (J) TO HAVE ATOLERANCE OF 0.05 AND A MINIMUM CLEARANCE OF 0.02. Q2. DIMENSION BUSHING (K) TO HAVE A TOLERANCE OF 0.07 AND A MAXIMUM INTERFERENCE OF 0.22. Q3. DIMENSION SHAFT (J) TO HAVE A TOLERANCE OF 0.02 AND A MINIMUM CLEARANCE OF 0.05. Q4. DIMENSION BUSHING (K) TO HAVE A TOLERANCE OF 0.07 AND A MAXIMUM INTERFERENCE OF 0.25. COMPLETE THIS CHART FROM THE INFORMATION GIVEN ABOVE E F G H ΟΙ Q2 Q3 Q4 J K Page 3 of 3