Engine Stand

An engine stand is a tool commonly used to repair large heavy gasoline or diesel engines. It uses a heavy cantilevered support structure to hold the engine in midair so that the mechanic has access to any exposed surface of the engine.

While small single-piston engines can commonly be laid on a table for repair, a large engine is normally meant to be supported from its engine mounts or from the flywheel transmission case mounts, and fragile components such as oil pans and valve covers would be crushed if the large engine were placed on a flat surface.

Engine stands are typically mounted on large casters so than an engine can be moved around the shop to different test and repair stations, and the engine can often be rotated in midair to provide easier access to underside surfaces of the engine.

The engine stand is commonly used in combination with the engine crane to remove or install an engine in a vehicle, break in that engine, and perform repairs.

(Source: http://en.wikipedia.org/wiki/Engine_stand & http://www.mikestoolsusa.net/ac-delco/acdelco-2000lbengstand.asp)

Spot Welding

Spot welding (RSW) is a process in which contacting metal surfaces are joined by the heat obtained from resistance to electric current flow. Work-pieces are held together under pressure exerted by electrodes. Typically the sheets are in the 0.5 to 3 mm (0.020 to 0.12 in) thickness range. The process uses two shaped copper alloy electrodes to concentrate welding current into a small "spot" and to simultaneously clamp the sheets together. Forcing a large current through the spot will melt the metal and form the weld. The attractive feature of spot welding is a lot of energy can be delivered to the spot in a very short time (approximately ten milliseconds). That permits the welding to occur without excessive heating to the rest of the sheet.

The amount of heat (energy) delivered to the spot is determined by the resistance between the electrodes and the amplitude and duration of the current. The amount of energy is chosen to match the sheet's material properties, its thickness, and type of electrodes. Applying too little energy won't melt the metal or will make a poor weld. Applying too much energy will melt too much metal, eject molten material, and make a hole rather than a weld Another attractive feature of spot welding is the energy delivered to the spot can be controlled to produce reliable welds.

Projection welding is a modification of spot welding. In this process the weld is localized by means of raised sections, or projections, on one or both of the workpieces to be joined. heat is concentrated at the projections, which permits the welding of heavier sections or the closer spacing of welds. The projections can also serve as a means of positioning the workpieces. Projection welding is often used to weld studs, nuts, and other screw machine parts to metal plate. It's also frequently used to join crossed wires and bars. This is another high-production process, and multiple projection welds can be arranged by suitable designing and jigging.

(source: www.millerwelds.com and welding-machinery-video.com)

Speedway Series 1404 110-Volt 30-AMP Spot Welder