MECH 200 1st Edition Lecture 7Running Fit – Machining such that parts may move within each otherLimit Dimensions – Minimum and Maximum size that will Fit or suffice in a part1. Unilateral Tolerance – the part may only be larger or smaller than the goal dimensiona. i.e. +0.00 -0.05 or +0.05 -0.00 2. Bilateral Tolerance – There is tolerance in both directionsa. i.e. +0.05 -0.05Standard Fit/ LT (Location Transitional) – The assembly can be disassembled and reassembled; the assembly has a limited amount of “play” built inDriving Fit/ FN – Permanent Assembly, There is room for driving (such as a hammer) if taken apart the piece is not reusable (i.e. a hole that is smaller than the shaft that is driven into it)Forced Fit – Permanent fit that requires a hydraulic press or item of that nature to assembleLexp = L * (delta T) * CTEAmount of Linear Expansion = (Original Length) * (Change in Temperature) * (Coefficient of Thermal Expansion)Cumulative Tolerance – on a part with multiple tolerances when one tolerance is maxed out it limits the tolerance on other portionsLow Tolerance – Cheaper Tools, Simpler Inspections, and Reduced Scrap resulting in significantly lower costBasic Hole Fit – Hole is set for a standard bitThese notes represent a detailed interpretation of the professor’s lecture. GradeBuddy is best used as a supplement to your own notes, not as a substitute.Basic Shaft Fit – The system is set up for use of standard sized stock1018 CRS – 1018 (designation) Cold Rolled Steel (Material Type) 18% Carbon (detail)General Dimensioning and Tolerance1) Symbols to Knowa) Straightnessb) Flatnessc) Roundnessd) Cylindricitye) Angularityf) Perpendicularityg) Parallelismh) ConcentricitySeparating Processes – Sawing• Most often Found in front end of 2nd Manufacturing Process• Equally important in 1st Manufacturing Processes of industrial stock• Dates back to 1600’s• Basics of process are rooted in the axe and adzeReciprocating Saws• Sawzall• Jigg SawBand Saw – Continuously Cutting, Blade can be flash welded (Electric currents are used to bond saw bladed ends