Difference between capstan and turret lathe

Capstan and Turret lathes are the advancements of the Engine lathes and centre lathes in which the tailstock is replaced by a hexagonal turret tool head with 6 different tools in the turret where the turret tool is rotated according to process requirements in each operation. The capstan and turret lathe although appear to be identical at the first sight but a lot of differences in construction, operation, and use. In this article, you can check it out some difference between these two lathe machines. 

Capstan lathe :

• Lightweight machine.
• These are usually horizontal lathe. 
• Turret head is mounted on a slide called ram which is mounted on the saddle.
• Suitable for bar work.
• The saddle is locked at a particular point and the ram is moved to provide feed to the tool.
• Only a limited amount of feed and depth of cut is provided for machining.
• The cross slide is mounted on a carriage that rests on bed ways between the headstock and the ram.
• The turret tool head is indexed automatically.
• Feed stop screws are used to control the distance of tool movement which is at the rear side of the turret.
• No such facility for moving turret at right angles.
• Feed rod gives for longitudinal feed.
• Used for mass production of small size equal part.
• It has hand-operated collet chucks.
• Heavy cuts on the workpiece can't be given because of non-rigid construction. 

Turret lathe :

• Heavyweight machine.
• Turret tool head is directly fitted on the saddle and both of them appear like one unit.
• Suitable for heavier chucking work.
• The saddle is moved to provide feed to the tool.
• They are heavy and durable.
• More feed and depth of cut are provided for machining.
• Some turret type lathes are equipped with side hung type carriage.
• To index the turret tool head, a clamping lever is released and the turret is rotated manually.
• Limit dogs are used to control the distance of tool movement.
• Some turret lathes have the facility of moving the turret at right angles to the lathe axis.
• Feed rod does not give for longitudinal feed.
• Used for mass production of large size equal part.
• It is accommodated with power chucks.
• Heavy cuts on a workpiece can be given because of the rigid construction of a machine. 
• These are available in the horizontal and vertical lathe. 

Related posts: 

1. Difference between capstan turret and engine lathe 
2. What is a lathe machine? Detailed information

Press forging advantages and disadvantages

Press forging defined as the process of shaping a metal that is placed between two dies by applying mechanical or hydraulic pressure. so now let us understand the key pros and cons of press forging to understand more about it. 

Advantages of press forging :  

• It deforms the workpiece completely. 
• The compression rate of the workpiece can be controlled automatically. 
• More economical for high volume productions. 
• Any size and shape can be created. 
• Requires less draft and produces lesser scrap so better dimensional accuracy. 
• Greater accuracy in terms of tolerance within 0.01 to 0.02 inch. 
• This operation is completed in a single squeezing so save time. 
• The plastic deformation goes deep into the centre of the workpiece provides uniform deformation. 
• The capacity of presses ranging from 500 to 9000 tons and the number of working strokes per minute can be high as 40 or even 50. 
• It is suitable for the mass production of nuts, bolts, rivets, screws, brake levers, valves.

Disadvantages of press forging : 

• The initial cost is higher because the cost of the crank press is always higher than of an equivalent hammer. 
• The difficulty of descaling the blank. 
• It is economical when the equipment is efficiently utilized. 

Explore more information:

1. Advantages and disadvantages of Drop forging
2. What is forging? Detailed information
3. Difference between open die and closed die forging

Drop forging advantages and disadvantages

Drop forging is a process that using the die with high strength, a metal blank on forging press will be plastic-deformed, then we will obtain the required shape, size, and internal quality. Now let us discuss the pros and cons of drop forging to understand more about it. 

Advantages of drop forging : 

• The production efficiency is higher. 
• Complex shaped metal parts can be forged with this process, and the distribution of metal flow line is more reasonable. 
• Improve the serving life of parts. 
• Achieve better surface quality, and smaller machining allowance and the size of this process is accurate. 
• Reduce machining work so save metal. 
• It will reduce the cost of spare parts. 
• The production operation is easy, so force or work is low. 
• Improved microstructure. 
• Finer grain size. 
• Continuous grain flow. 

Disadvantages of drop forging : 

• For short runs, this process is not very economical due to the high cost of die production.
• Drop forging presents a dangerous working environment.

Explore more information:

1. Advantages and Disadvantages of Closed die forging
2. Advantages and Disadvantages of Open die forging

Difference between drop forging and press forging

Drop forging is when half of the die is dropped from a height onto the other half of the die, that will contain the hot metal workpiece to be formed and is more suitable for mass production. Press forging is instead of dropping half the die onto the other half the two halves are put together and pushed together under a large pressure to forming the object. 

Main difference : 

The difference is that drop forming leaves the center of the metal not so hard as the outside, but the press forming gives more uniform hardness for larger components. We could also differ forgings from its temperature, such forgings are named cold forging, warm forging, and hot forging. 

Difference :

• The metal is shaped by means of a series of blows in drop forging while in press forging, the metal is shaped by means of a single, continuous stroke. 
• The pressure applied is impacted, and in multi-stroke in drop forging, while the pressure applied is slow, steady and continuous in a single squeezing action in case of press forging. 
• The deformation of metal is more at the surface layers than that of a center of the metal in case of drop forging, while it is uniform, simultaneous and deep penetrating at the center of the metal part. 
• The jarred impressions are obtained in drop forging while impressions obtained in press forging are clean. 
• The draft angles used are more in case of drop forging than that of press forging. 
• Tong holds are normally required for manipulating dies in drop forging whereas in press forging tong holds are not required. 
• The initial cost of drop forging is less as compared to press forging. 
• The drop forging is suitable for almost all types of medium size forgings and press forging is recommended when machine utilization is quite high. 
• The drop forging is a relatively slow process and has moderate production rates where press forging is a faster and higher production rate. 

Closed die forging application

Due to its high precision, closed die forging is preferred for small critical parts with consideration for safety. It is mainly used to produce small products like forged fittings, forged lifting and rigging hardware, forged automotive parts, etc. Now let we check the applications of closed die forging one by one below. 

Applications of closed die forging : 

• According to the advantages of closed die forging, it has become the main metal forming process in modern manufacturing. It can be used for lots of metal components for cars, aeroplane, heavy trucks, shipbuilding, etc. 
• The motivation that encourages many manufacturers to change the production process into closed die forging because it offers better surface finish with good quality, also the price is competitive so we could use this process in below application. 

Automotive application: Connecting rod, control arm, rock arm, axle shafts, axle beams, axle arms, steering yokes. 

Construction machinery applications: Bucket teeth, excavator. 

Agriculture applications: Shafts, spike harrow teeth, tie rod ends, gears. 

Oilfield applications: Elbow, hammer union nuts, cross, tee. 

Mining applications: Ground foundation and auger bits. 

Open die forging application

The differences between open and closed forging process make the end product look different and the major difference in application lies in the size of the product. Now let we understand and applications of open die forging.

Applications : 

• It is the rough process of forging as it does not involve a fixed die size so this process does not use in precision. 
• This process is best suited for forging bigger and heavier metal parts like forged shafts and rollers that find their application in railways because not required much surface finishing machining and create ultra-finished products. 
• The advantages of this process range from better microstructure as the grain size are fine and have a continuous flow this the products in forging method include forged long shafts, forged rollers, and forged cylinders which mostly used for the application of many industries. 

Closed die forging advantages and disadvantages

When it comes to shaping a metal part, forging is the one used to shape the metal in a controlled manner using plastic deformation while there are different types of forging methods, one of the most common is closed die forging. This technique involves the pressing of hot round bars and their net shaping in closed dies. This process provides the desired shapes and is being wide applications for all industries, including engineering, construction, aerospace, power generation, defence, oil, and gas, etc. Let us now have a look at some of its major pros and cons to understand more about it.

Advantages of closed die forging :

• The forging process of closed die creates net shapes or near-net shapes. 
• This process offers superior mechanical properties, higher product strength, and toughness.
• Closed tolerance can be achieved through this process close to + / - 0.3 mm. 
• It is suitable for steel brass and aluminium as well as some other alloys too. Thus, no material limitation. 
• Better surface finish so saves the cost of machining. 
• It is a cleaner and greener process as compared to casting so it is environmentally protected. 
• Good reproducibility and high production rate. 
• Parts of sizes up to 25 tons can be produced. 

Disadvantages of closed die forging :

• This process involves a higher tolling cost that makes it expensive. However, it can be suitable for mass production. 
• Closed die forging may not be helpful for complex and large products.
• This process has a limitation on dimension. 

Thus, this process is overall a cost-effective process when used for mass production and to gain higher product strength and toughness.

Advantages and disadvantages of open die forging

Open die forging is only suitable for simple shapes for its less dimensional accuracy, and high skill operators are required, the dies of this process are simple and less expensive which is the simplest process of all the forging process. In this article, you can check it out the pros and cons of open die forging to understand more about it. 

Advantages of open die forging : 

• Better fatigue resistance and improved microstructure.
• A continuous flow of grain and finer size of the grain.
• Increased strength and prolonged part life.
• Less material waste.
• Reduced chance of voids.
• Cost savings are valuable.

Disadvantages of open die forging : 

• Close tolerance and higher precision parts cannot be formed.
• To achieve the desired dimensions, machining is often required.

Explore more informaion:

1. Advantages and disadvantages of Press forging

Difference between open die forging and closed die forging

The method of deforming a piece of metal between various dies that does not fully enclose the material is open die forging. The metal is modified by a sequence of movements as the dies "hammer" or "stamp" material until the required shape is achieved. 

Let us have a deep insight into the difference between open and closed die forging.

Difference between open and closed die forging : 

• Open die forging is also known as free forging, meaning metal billets compressed under the external compressive force and deformed to desired dimensions in a freeway without forging dies while closed die forging is also known as impression die forging, is a process that heated by medium frequency induction heating furnace to high temperature and forced between upper and lower dies to get expected shapes like the drawing.
• Both forging processes are also different in the side of their processes. Moulding dies are firstly made for closed die forging, and then forged steel bars are placed on the dies and drop forged to desired shapes. In open-die forging, it involves enormous compressive force imposed by the continuous strike of a hammer to make the metal billets deformed. 
• Open die forging will require further rough machining due to its free forging and imprecise dimensions may be reached by second precision machining while closed die forging is more common in small parts for its high precision used to make forged fittings, forged flange and forged automotive parts. 
• The open die metal forged parts are more suitable for larger parts in a number of tons whereas for small parts closed die forging is preferred as high precision is obtained in closed die forging. 

Difference between hot rolling and cold rolling

One of the important processes in metal manufacturing is rolling, but there are two methods available for rolling one is hot rolling and another is cold rolling. It is a common misconception that these processes relate to a specification of metal or grade of metal instead, they refer to how metal is processed at the mill. Now in this article, you can check it out the hot rolling vs cold rolling and some key difference between them. 

What is hot rolling?

Hot rolling is the process in which rolling the steel at a high temperature which is higher than the recrystallization temperature of steel.

What is cold rolling?

Cold rolling is a similar process to hot rolling, the steel is subjected to further cooling process at room temperature in cold reduction mills after being rolled. 

Main difference :

The main difference between these two processes is the temperature in which they are performed. Hot rolling is under high temperature also called as above recrystallization and the cold rolling is under room temperature also called as below recrystallization. 

Some more difference between hot and cold rolling process is explaining below. 

• Hot rolling is the father of cold rolling which follows hot rolling. 
• Hot-rolled metal does not show work hardening effect whereas it shows in cold roller metal. 
• Co-efficient of friction between two rolls is higher in hot rolling it may even cause shearing of metal in contact with rolls and co-efficient of friction us lower in cold rolling. 
• Experiment measurement is difficult in hot rolling while it can be carried out easily in cold rolling.
• Heavy reduction area of a workpiece can be obtained in hot rolling whereas heavy reduction is not possible in cold rolling. 
• The radius of rolls is generally higher for hot rolling and it relatively smaller in cold rolling. 
• The very thin section is not obtained by a hot rolling process vice versa in the cold rolling process. 
• Hot rolling does not allow partial buckling of cross-section while cold rolling is allowed to have local buckling. 
• Mechanical properties are improved by beaking cast structure thus toughness increases in hot rolling and cold rolling increases the tensile strength and yield strength. 
• The hot-rolled surface is not good it has metal oxide on it while the cold-rolled surface is smooth and oxide-free. 

Positive caster Vs Negative caster

Positive caster is when the steering axis is in front of the verticle axis and negative caster is when the steering axis is behind the verticle axis. In this article, you have to clear your mind to check it out the difference between positive and negative caster, comparison and much more details about them.  

Difference : 

• Positive caster occurs when the axis of the steering wheel is ahead of the vertical axis and negative caster occurs when the axis of the steering wheel is behind the vertical axis.  
• A significant amount of positive caster provided that your vehicle has a well-fitted power steering system while negative caster symptoms make the steering wheel light and increasing the susceptibility of your vehicle, and make its path accurate without proper direction.
• Positive caster angles run between 3 - 5° on modern vehicles gives a good mix of highway stability and steering feel. Negative caster is opposite to positive caster. 

Summary : 

If you modify the caster settings on your vehicle, make sure that you keep the angular degrees of the casters completely symmetrical with one another. If you make the mistake of miscalculating the angles of the casters on various wheels of your vehicle, then you will find your car will start pulling more towards one side with respect to another side which doesn't have much of a caster angle. 

Difference between caster and camber

Definition of caster angle : 

The caster angle is the angular displacement of the steering axis from the vertical axis of a steered wheel in a car, motorcycle, bicycle measured in the longitudinal direction. In other words, it is the angle between the pivot line and vertical. 

Definition of camber angle : 

The camber angle is the angle made by the wheels of a vehicle, it is the angle between the vertical axis of the wheels used for steering and the vertical axis of the vehicle when measured from the front or rear. 

Camber angle is taken care of when designing the steering and suspension.

If the top of the wheel is farther out than the bottom, is called positive camber. If the bottom of the wheel is farther out than the top, is called the negative camber. 

This article is about the caster vs camber, what is caster angle, what is camber angle and the comparison between caster and camber.

Difference between the caster and camber : 

• Caster is the angle between the verticle line and kingpin centre line in the plane of the wheel when the view from the side is called the caster angle. Camber is the angle between the centre line of the tyre and the vertical line viewed from the front of the vehicle is known as the camber angle.
• Caster is the steering angle with respect to the wheel's centre and camber is the wheel's angle with respect to its centre. 

Explore more information: 

1. What is a caster?
2. What are toe-in and toe-out?
3. Difference between understeer and oversteer

How to adjust correct steering angle?

The perfect steering is achieved when all the four wheels are rolling perfectly under all running condition. While taking turns, the perfect rolling condition is satisfied if the axis of the front wheels when produced meet the rear wheel axis at one point. Then this point is called the instantaneous centre of the vehicle. 

It can observe that the inside wheel is required to turn through a greater angle than the outer wheel. The larger the steering angle, the smaller the circle of turning. However, a maximum to which we can go as the steering angle. 

It has been found that steering angle can have a maximum value of about 44 degrees. 

The extreme positions are called lock positions on either side. The diameter of the smallest circle which the outer front wheel of the car can traverse and get when the wheels are at their extreme positions is referred to as the turning circle.

Now let we discuss the formula for correct steering angle. 

Correct Steering Angle

Let the axis of the inner wheels makes a larger angle θ than the angle φ subtended by the axis of an outer wheel. 

Let a = wheel track
b =  wheelbase
c = distance between the pivots A and B of the front axle

From the triangle IBP 

cotθ = BP / IP 

From the triangle IAP

cotø = AP / IP = AB + BP / IP = AB / IP + BP / IP = c / b + cotθ

cotø - cotθ = c / b 

This is the fundamental equation for correct steering. 

Explore more information: 

1. What is a caster?
2. Difference between the caster and camber

What is Toe in and Toe out | Definition | Effect

Definition : 

Toe-in is the amount by which the front wheels are mounted closer together on the front than on the back when the vehicle is stationary and viewed from the top. The wheel can be set closer to the rear than to the front, in which case the difference of the distances between the front and rear wheels is called toe-out. 

Effect : 

In rear-wheel-drive vehicles, there is usually an inherent tendency for the wheels to toe-out due to purposeful deviation from centre point steering due to errors in the steering angles of the inner and outer bends of the wheels. 

There is usually an inherent tendency for the wheels to toe-out in rear-wheel drive vehicles just because of purposeful deviation from centre point steering due to errors in steering angles of the inner and outer wheels bends. In order to compensate for this tendency, a small amount of toe-in was initially provided in such vehicles so that the wheels move perfectly straight ahead under normal turning condition. However, the initial toe-out was provided in the case of some front-wheel-drive vehicles to counter the toe-in present therein. 

In rear-wheel-drive vehicles, due to errors in the steering angles of the inner and outer bends of the wheels, there is usually an inherent tendency for the wheels to toe out. 

In rear-wheel-drive vehicles, there is usually an inherent tendency for the wheels to toe out due to purposeful deviation from centre point steering due to errors in the steering angles of the inner and outer bends of the wheels. A small amount of toe-in was initially provided in such vehicles to compensate for this tendency so that the wheels move perfectly straight ahead under the normal turning conditions. 

Toe-in generally does not exceed 3 mm. 

A toe-in wheel alignment can help to reduce oversteer problems and increase stability in front-wheel drives vehicles. 

A toe-out alignment can help to mitigate issues related to understeering and can improve the handling of a vehicle that has rear-wheel drive. 

Explore more information: 

1. What is a caster?

What is caster | Definition | Effect

Definition : 

The caster angle is called the angle between the kingpin centre line for the steering axis and the vertical in the wheel plane. 

If the centre line of the kingpin meets the ground at a point ahead of the verticle wheel centre line is called the positive caster and if it is behind the verticle wheel centre line is called the negative caster. 

Effect : 

The steering axis pulls the front tires, while the tire drag due to the weight of the vehicle is on the vertical line in the centre of the footprint. Since the positive caster steering axis would meet the ground ahead of the tire print centre, the later would always follow former, thus positive caster provides directional stability on the car wheels. 

A positive caster increases the effort required to turn the steering wheel. In the case of negative caster steering, it may be noted that it would be unstable. Example -There would be poor directional control, as in this case the centre of the tire print leads the steering axis. Extremely negative casters would cause shimmy and consequently cupped wear of the front tires. 

As the change of caster angle, the other angles of the steering geometry, the chamber, the inclination of the kingpin and the toe0in or toe-out are changed. Therefore, it is very important that this angle is adjusted first of all while doing the adjustment job. 

Approximately 3 degrees of castor gives good results. 

Explore more information:

1. Difference between caster and camber

Difference between understeer and oversteer

Understeer and oversteer both terms are both related to vehicle dynamics and especially wheel alignment. They are related to the sensitivity of an automobile to its steering. In this article, we can check out what is understeer and oversteer and the difference between them. 

What are Understeer and Oversteer?

When a car steers less than what the driver commands is called understeer and oversteer is the turning of the car more than what the driver commands. These actions depend on the changes in lateral acceleration and steering angle. 

Difference between understeer and oversteer : 

• Both of these are caused by the difference in slip angles for the front and rear wheels.

What is a slip angle?

It is basically the angle between the direction of the wheel heading or travel and the direction of the car heading or travel. 

• Understeer means lack of grip while oversteer means the front side of the vehicle has more grip than the backside. 
• When understeer happens, the driver will have little response from the steering wheel on the other side when oversteer happens, it makes the car spin when driving into a corner. 
• Understeer takes place when the vehicle's front wheels begin to plough straight despite turning the steering wheel and oversteer takes place as a result of the rear end of a car being fishtailed or sliding out. 
• Front-wheel drive cars are prone to understeer while rear-wheel cars are susceptible to oversteer. 
• Understeer most commonly happens due to early accelerating while turning in a corner so you can lift the weight distribution that takes the control off of the front tires and leads to the dangerous situation while oversteer is not something to be concerned about because it happens in everyday driving thus it could be dangerous if occurs in snowy, muddy or rainy conditions. 
• Applying more suspension or increasing the front wing can minimize the understeer and also tire pressure adjustment helps sometimes while you have to do the opposite to fix this problem you have to loosen the suspension or down-force to drop the grip. 

Explore more information:

1. Difference between caster and camber

Advantages and disadvantages of resistance welding

The resistance welding process is also a fusion welding process where both heat and pressure are applied to the joint but no filler metal or flux is added. The heat necessary for the melting of the joint is obtained by the heating effect of the electrical resistance of the joint and hence, the name is resistance welding. In this article, you can check out the advantages and disadvantages of resistance welding to understand more about it.

Advantages of resistance welding :

• It is a very economical process because there are no consumables used in this process so environment-friendly too. 
• The heating of the workpiece is confined to a very small part so less distortion.
• Very little skill is required to operate a resistance welding machine because easily automated. 
• By this process also weld dissimilar metal as well as metal plates of different thicknesses.
• Welding speed is very high.
• Weld up to 0.1 mm thin as well thick up to 20 mm metals. 
• High production rate thus suited for mass production. 
• This process does not require any filler metal, flux and shielding gas. 

Disadvantages of resistance welding :

• The resistance welding machine is highly expensive.
• Lower tensile and fatigue strength.
• It is limited only to lab joints.
• The limit of sheet metal thickness is less than 3 mm.
• Less efficient for high conductive materials. 
• High electric power is required. 

Advantages and disadvantages electrochemical machining

A method of removing metal by an electrochemical process is called electrochemical machining in short ECM. This process is usually used for mass production and working with extremely hard materials that are difficult to machine using other processes but its use is limited to electrically conductive materials. Let us have a deep insight into the advantages and disadvantages of electrochemical machining in this article. 

Advantages of Electrochemical Machining :

• The metal removal rate is quite high for high-strength-temperature-resistant (HSTR) materials as compared to the conventional process.
• Accurate machining.
• Residual stress is low.
• The surface finish is in the order of 0.2 to 0.8 microns.
• No direct contact between tool and workpiece.
• Negligible wear and tear of tool material.
• Environmental friendly.
• Possible to machine non-rigid and open workpieces.
• It can be a machine configuration that is beyond the capability of the conventional machining process.
• Extremely thin sheets of metal can be worked easily without distortion.
• A job with complex shapes can be machined easily and accurately.
• Several holes can be done at once during drilling.
• ECM is a time-saving machining process as compared to conventional machining.
• Deburring can be done in hard to access areas.
• Fragile and brittle materials can be machined easily by ECM without cracking or breaking.
• The metallic workpiece is not damaged due to thermal stresses.

Disadvantages of Electrochemical Machining :

• Power consumption is more.
• Initial tooling can be timely and costly.
• Non-conducting materials can not be machined.
• The process is costly because of expensive equipment.
• A continuous supply of electrolytes is necessary.
• Steady voltage should be maintained during the whole process.
• Corrosion and rust of the ECM machine can be a hazard.
• If hydrogen is liberated at the tool surface then it is possible to suffer from hydrogen-embitterment of the surface.
• There may be a possibility of damages because of sparks.
• Conventional machining produced more improved fatigue properties than ECM.

Advantages and disadvantages of internal expanding brake

An internal expanding brake consists of two shoes where the outer surface of the shoe is lined with some friction material to increase the coefficient of friction and prevent wearing away of the material. This type of brake is used in cars and light trucks. Let us have a deep insight into the advantages and disadvantages of internal expanding brake in this article. 

Advantages of internal expanding brake: 

• Requires little maintenance.
• It has a simple construction with a small number of parts.
• It is cheaper as compared with other types of brakes.
• It is more reliable due to the small number of parts.
• Offers protection against the entry of foreign particles.
• Produce a large braking torque with a small actuating force.

Disadvantages of internal expanding brake :

• Poor heat dissipating capacity.
• It becomes self-locking due to wear.

Advantages and disadvantages of Stirling engine

A Stirling engine is operated by cyclic compression and expansion of air or other gas at different temperatures and convert heat energy into mechanical work thus it is also called a heat engine. Let us have a deep insight into the advantages and disadvantages of the Stirling engine to know more about it. 

Advantages of Stirling engine :

• Stirling engines can run directly on any available heat source not produced by combustion so they can run heat from biological, geothermal, nuclear sources or solar.
• Most Stirling engine types have the cool side of the engine bearing and seals. They only need less lubricant and last longer than other types of engines that reciprocate.
• In some ways, the engine mechanisms are simpler than other types of engines that reciprocate.
• No valve is needed. 
• A Stirling engine uses a single-phase working fluid that keeps an internal pressure close to the pressure of design.
• Low operating pressure permits the use of lightweight cylinders in some cases.
• They can be constructed to run smoothly and without an air supply.
• In cold weather, they start easily and run more efficiently.
• They can extremely flexible.
• They can be used as CHP in winter and as a cooler in summer.
• Waste heat is easily harvested.
• Stirling engine is useful for duel-output heat and power systems.

Disadvantages of Stirling engine :

• Stirling engine requires heat exchangers for heat input and for heat output.
• For efficient operation, all thermodynamic cycles require large temperature differences.
• Dissipation of waste heat is especially complicated because coolant temperature is kept as low as possible to maximize thermal efficiency.
• A Stirling engine cannot start instantly and literally needs to warm up. It is true for all external combustion engines but for this warm-up time may be longer.