I think many of us with vehicles seriously overestimate or underestimate what we could tow with it. You might look at a boat, utility trailer, or travel trailer and ask yourself “I wonder if my car could handle that?”

Now where would you go for that kind of information? Most people would go straight to the owner’s manual of their car. The problem is, the information in that manual will be so watered down and generic that you can’t really trust it.

It’s going to say something like this: “towing capacities are calculated under the assumption of a standard equipped vehicle, normal driver, and trailers. Any other equipment or passengers will reduce the amount of weight your vehicle can handle.”

Huh? So how on earth can you evaluate your real towing capacity? The first thing you have to understand the vehicle manufacturer is using a completely stripped down version of the car or truck to beef up the towing rating. Makes sense right?

They’re trying to sell cars, and if you’re a family with a tent trailer, seeing a super high towing rating on that little station wagon could be the factor that gets you to buy. That’s why you need to bring a skeptical eye to that owner’s manual.

The last thing you want is to load up your trailer with a few quads or motorcycles, head up to the mountains, and then have your transmission go out because you trusted the manufacturer’s published towing capacity. That could be a very expensive getaway.

Here are some terms you want to be familiar with in evaluating your actual towing capacity:

Unloaded Vehicle Weight (UVW)
You know all those times you’re headed down the interstate near the border of the state you’re entering or leaving? One of the best ways to find out your unloaded vehicle weight is to stop at one of them, pay the $5 or $10 fee, and have them weigh your car or truck.

If you do stop at one of those weigh stations, try to have your gas tank as full as possible to make the measurement more accurate.

Gross Vehicle Weight Rating (GVWR)
This is the maximum weight your tow vehicle can be without wrecking your car, truck, or suv. There are a few places you might find this number – it might be under the hood in the engine compartment, or on a sticker in a door frame, or maybe even in the owner’s manual. It’s important to know this number because the foundation for safe towing is not attempting to pull something that is just too heavy for your car.

The bottom line when towing is not to overdo it. When you buy a vehicle, if you know it’s going to be used for towing, be realistic about the capacity of the car or truck you’re buying.

The lightweight family sedan you’re buying is probably not intended to pull a 20 foot boat, or a large travel trailer. If you know you’re going to be doing lots of traveling, camping, RVing, and other recreation, be honest about what type of tow vehicle you’re going to need.

I would recommend buying a solid 8 cylinder engine with a transmission calibrated for heavy duty jobs. I would rather overkill on the vehicle than risk doing thousands of dollars in damage to my car or my trailer. Not to mention the people I’m sharing the road with.

Jeremy teaches people about installing a trailer hitch and also advises them on the right way to set up trailer hitch covers.

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Welding is a progression using heat or pressure to join mutually materials such as metal or synthetic. Welding Equipment is a ordinary way for joining metals, and is used in the production of many goods, including automobiles, ships, trains, buildings, and bridges.

MIG Welding Equipment

MIG Welding equipments are obtainable in various sizes ranging from a small, portable 115v, 20 amp model to full sized shop automotive service equipment. MIG welders are widely known for high quality performance, though cost-effectively priced. You can exercise control over the superiority of the weld with the aid of many diverse settings. MIG Welding equipments come with cold running temperatures. The machines also recommend advantageous warranty opportunities.

It is universal knowledge that MIG Welders use a wire feed and produce a lower heat. This stops metal distortion and allows for a high quality job on thinner metals such as those involved in auto body job.

MIG welders feed a constant stream of wire with a pull of the trigger. You must be additional cautious in choosing the consumables. Wire, for instance, comes in easy-to-use flux core wire for a rapid job on thicker resources, or a gas/solid wire amalgamation for all other work.

TIG Welders

Most TIG welding machines come with more than a few attractive features. With push button control panels, the machines are exceptionally accessible and some high-end models give you the option to easily adjust for repeatable weld cycles, start, and weld crater. To make specially the shape and size of the bead, you can choose models with true square wave AC output and pulse mode. Purchase models that have safety features like warning code circuitry and voltage protection.

One of the principal advantages of TIG welder is it heats and joins the two metal pieces together exclusive of the need for filler materials. Most operators know that MIG welders join metals much faster than TIG welders. But, TIG welders produce greater degree of precision, so essential for certain types of jobs. The possibility of preventing cracked seals or damaging the weld is also considerably decreased in TIG machines.

Plasma Cutting

Some latest models of plasma cutters come with a host of features - single-dial controls for easy adjustments, pressure gauges and air pressure regulators all aimed at cleaner and sharper cuts. Other features comprise parts-in-place indicators, line voltage compensation, and thermostatic protection. Above all, if you wish to do monotonous work with complex cuts, CNC robotic interfaces will make sure consistent and precise cuts every time. Please know that most up-to-date types of plasma cutters have an inverter in place of the transformer.

With several different styles of plasma cutters available, your choice becomes wider. Duty cycle is a key aspect in your business decision. Usually, you will find that bigger machines can handle thicker metals and run longer to give it a larger duty cycle. Furthermore watch for the rating that is assigned to plasma cutters by the producer. This will tell you how long each division can cut through mild steel before needing to be cooled down.

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A starter is an electric motor needed to turn over the engine to start it.
A starter consists of the very powerful DC electric motor and starter solenoid that is attached to the motor (see the picture).
A starter motor requires very high current to crank the engine, that's why it's connected to the battery with large cables (see lower diagram).
The negative (ground) cable connects "-" battery terminal to the engine block close to the starter.
The positive cable connects "+" battery terminal to the starter solenoid.
The starter solenoid works as an electric switch - when actuated, it closes the circuit and connects the starter motor to the battery. At the same time, it pushes the starter gear forward to mesh with the engine's flywheel.

How the starting system works:
When you turn the ignition key to the "Start" position, the battery voltage goes through the starter control circuit and activates the starter solenoid, which in turn energizes the starter motor. The starter motor cranks the engine.
A starter can only be operated when the automatic transmission shifter is in "Park" or "Neutral" position or if the car has a manual transmission, when the clutch pedal is depressed.
To accomplish this, there is a Neutral safety switch installed at the automatic transmission, (or at the clutch pedal).
When the automatic transmission is not in "Park" or "Neutral" (or when the clutch pedal is not depressed), the neutral safety switch is open and the starter relay disconnects the starter control circuit.

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A variety of NDT techniques are available for detection and characterisation of defects in welds. All NDT techniques are based on physical principles. Nearly every form of energy is used as probing medium in NDT. Likewise nearly every property of the materials to be inspected has been made the basis for some method or technique of NDT. In general, NDT methods involve subjecting the material (being examined) to some form of external energy source (X-rays, ultrasonic, thermal wave, electromagnetic fields etc.) and analysing the detected response signals (refracted energy, induced voltage and diffracted energy).

Inspection of welds

The beam of radiation must be directed to the middle of the section under examination and must be normal to the material surface at that point, except in special techniques where known defects are best revealed by a different alignment of the beam. The length of weld under examination for each exposure shall be such that the thickness of the material at the diagnostic extremities, measured in the direction of the incident beam, does not exceed the actual thickness at that point by more than 6%. The specimen to be inspected is placed between the source of radiation and the detecting device, usually the film in a light tight holder or cassette, and the radiation is allowed to penetrate the part for the required length of time to be adequately recorded.

The result is a two-dimensional projection of the part onto the film, producing a latent image of varying densities according to the amount of radiation reaching each area. It is known as a radiograph, as distinct from a photograph produced by light. Because film is cumulative in its response (the exposure increasing as it absorbs more radiation), relatively weak radiation can be detected by prolonging the exposure until the film can record an image that will be visible after development. The radiograph is examined as a negative, without printing as a positive as in photography. This is because, in printing, some of the detail is always lost and no useful purpose is served.

Before commencing a radiographic examination, it is always advisable to examine the component with one's own eyes, to eliminate any possible external defects. If the surface of a weld is too irregular, it may be desirable to grind it to obtain a smooth finish, but this is likely to be limited to those cases in which the surface irregularities (which will be visible on the radiograph) may make detecting internal defects difficult.

After this visual examination, the operator will have a clear idea of the possibilities of access to the two faces of the weld, which is important both for the setting up of the equipment and for the choice of the most appropriate technique.

Defects such as delaminations and planar cracks are difficult to detect using radiography, which is why penetrants are often used to enhance the contrast in the detection of such defects. Penetrants used include silver nitrate, zinc iodide, chloroform and diiodomethane. Choice of the penetrant is determined by the ease with which it can penetrate the cracks and also with which it can be removed. Diiodomethane has the advantages of high opacity, ease of penetration, and ease of removal because it evaporates relatively quickly. However, it can cause skin burns.

RADIOGRAPHY
As the X-ray absorption coefficient depends strongly on material density, radiography is particularly effective at detecting volumetric defects, which contain either extra mass or missing mass (such as slag inclusions or porosity). The benchmark for radiographic inspection of welds is still high-quality film radiography and good radiographic practice is now enshrined by a series of national standards, covering factors such as choice of voltage, film–source distances, intensifiers, image quality indicators, film density, film processing, etc. There have been a number of advances in radiography over the past 10–15 years including more reliable microfocus tubes, real-time radiography and the application of image processing techniques to sharpen the image and to increase the contrast. For better definition of defects and delectability of small defects like micro-cracks in thin components and complex geometries, high resolution micro-focal X radiography has an edge over the conventional radiography. One of the important applications of micro-focal radiography is evaluation of tube to tube sheet weld joints of PFBR steam generators (made by welding between pull out of tube sheet and the tube).

The most significant recent development in radiography has been the real-time radiography. Real time radiography or fluoroscopy differs from conventional radiography in that the X ray image is observed on a fluorescent screen rather than recorded on a film. Fluoroscopy has the advantages of high speed and low cost of inspection. Present day real time systems use image intensifiers, video camera and monitor. The principal advantages of real-time radiography are that it is well suited to automation and the images of the component under inspection are available directly without time delays due to film exposure and processing. Furthermore, as the images are provided in digital form, image processing and automatic defect interpretation softwares can be readily incorporated into the inspection system. On-line monitoring of welding is another possibility by real time radiography. Direct examination of the welds in real time saves films and time and is found to be cost effective in the long run [5]. The use of microfocal units in conjunction with image intensifying system greatly enhances the versatility and sensitivity of the real time radiography, by way of zooming or projection magnification.

With the advent of image processing systems, the sensitivity that can be achieved is comparable to film sensitivity. The stored or digitized X-ray image can be subjected to image processing and enhancement techniques such as contrast stretching, edge enhancement, special filtering, differentiation, averaging, and pattern recognition for enhanced detection of defects and also for obtaining quantitative information. The versatility of image processing is that this can be performed in real time as well as on film images. Figures 1(a) and 1(b) show typical radiograph of a weld joint. Figure 1(a) gives the raw image wherein penetrameter wires are not clearly seen. After contrast stretching and image enhancement (Fig. 1(b)), the lack of penetration can be seen and the wire penetrameters can be identified thereby increasing the sensitivity.

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