Design of Product and Machine Tools — Winter 2021

What is the difference between “Product Design” and “Machine Tool Design”?

Explain how “Productivity” and “Accuracy” requirements are met in the design of machine tools.

What are the causes and harmful effects of vibration in machine tools? How would you eliminate vibrations in a machine tool?

Which material is generally used for design of machine tool bed? Why?

Draw cross sectional sketches of “Flat Guide ways” and “Inverted V shaped Guide ways” Also discuss their features.

Derive an equation for (l2/h) optimum ratio for steel and cast iron beam. Conclude stiffness or strength criterion by comparing volumes of both materials.

With the help of neat sketch describe methods of adjusting clearances in slide ways.

Compare and Contrast stepped regulation versus step less regulation.

Draw a ray diagram for a gearbox of machine tool having 9 spindle speeds ranging from 90 to 1800 rpm, considering the gearbox should be compact one.

For the above example also draw structural diagram. Considering motor rpm 1400 show the layout of gear box and find out number of teeth on various gears.

Define life of a ball bearing. What is equivalent load?

How to avoid metal to metal condition (MMC) in hydrodynamic bearing? Explain with suitable diagram.

Design a hydrodynamic bearing for a shaft of centrifugal blower from the following data: Blower speed : 600 rpm, Shaft Diameter : 50 mm Bearing load due to belt force : 3000 N Bearing load due to weight of rotor : 600 N Expected temperature of oil : 70⁰C Ambient temperature : 30⁰C C/d ratio : 0.0015, Minimum film thickness : 0.019 Calculate: (i) Actual altitude (ii) Type of oil used (iii) Power loss (iv) Heat generated (v) Actual minimum film thickness.1

Will you prefer a cast hook or forged hook in cranes? Give reasons for your answer.

Give merits of using a pulley tackle in lifting and hoisting machine.

The 6 x 19 wire rope is used to lift the cage of vertical mine hoist 400 m deep. The weight of the cage is 1200 kg (mass) and it has to lift 3000 kg of ore at a speed of 15m/s which has to be attained in 10 seconds. Take Dmin/d = 75. Assume factor of safety 5 and E=8 x 104 N/mm2. Weight of the rope/metre = 0.0034d2 kg. Cross sectional area of rope = 0.38d2. Ultimate stress for wire rope is 1800 N/mm2. Determine diameter of rope.

Why economic evaluation of designed product is needed before launching of any product in market?

What is product development? How prototype can help to improve a product?

Consider a product as keyboard of desktop and present a case using ergonomic and functional aspect of product design.

Which information is essentially required before starting a designing of stepped drive?

What are the major advantages of geometric progression series used in machine tool drives?

Elaborate functions performed by spindle unit and requirements of it.

Draw and brief any ONE device for intermittent motion in Machine Tool.

What are the causes of Machine Tool Chatter?

Draw commonly used column sections used in machine tools and brief about their applications