Midterm 1

Question 1

Cutting force (lbs) =

Answer 1

cutting speed sfpm

Question 2

In terms of strap clamps, what do washers prevent?

Answer 2

Damage to the straps

Question 3

In terms of straps, what do fasteners prevent?

Answer 3

Damage to the straps

Question 4

What is the mechanical advantage a thread provides?

Answer 4

It’s an inclined plane

Question 5

True/False

Finer threads are better to withstand vibration and chatter

Answer 5

True

Question 6

What is an example of a positive clamping force?

Answer 6

Using a mechanical engagement (locking a door)

Question 7

What is a non-positive clamping force and give an example.

Answer 7

Using another force to counteract the force

A hydraulic clamp, or two people pushing opposing directions on a door

Question 8

Magnetic chucks

Answer 8

Non mechanical clamping

Clamping pressure evenly across part

Mainly used with magnetic material

Can apply pressure indirectly to non-magnetic materials

Mainly electromagnetic and permanent type

Question 9

Vacuum chucks

Answer 9

Can hold any type of non-porous material

Draws out air between chick face and material

Needs a mask in most types

Uses a lot less space than traditional clamps. Perfect for 5-axis CNC machines and cutting engine blocks

Question 10

What is a vaccumag plate?

Answer 10

A combination of a vacuum chuck and magnetic chuck. It’s a vacuum plate mounted on top of a magnetic plate.

Question 11

Clamping force calculation (in lbs):

Answer 11

static friction coefficient)

• safety factor (usually 2)

Question 12

What is the definition of a permanent bushing, and give two examples.

Answer 12

Permanent - not regularly changing applications (could possibly drive location hole larger if changed regularly)

Ex. Press fit, and cast in place (epoxy resin)

Question 13

What are two examples of a renewable bushing? (The opposite of permanent bushing)

Answer 13

Slip bushing - multiple operations

Fixed bushing - single operation

Question 14

List 7 objectives of tool design

Answer 14

1. Provide simple, easy-to-operate tools for maximum efficiency
2. Reduce manufacturing expenses
3. Design tools that consistently produce high quality parts
4. Increase the rate of production
5. Make it fool-proof
6. Select materials that give adequate tool life
7. Provide protection/safety for the operator

Question 15

What are jigs and fixtures?

Answer 15

Jigs and fixtures are production-work holding devices used to manufacture duplicate parts.