- Magnetic base
The vertical post, side arm (as shown in the image at right) and the dial indicator (not shown) are connected by two swivelling connectors. These connectors allow free movement of the arms so that the indicator can be presented to the work in a suitable orientation. The magnetic base may have a "V" cut into the bottom of the base or the back, this "V" allows the base to be attached to a round bar such as the column of a drill press.
The base is made from two blocks of iron, with a round cavity bored through the centre. The halves are joined together with a non-ferrous material such as brass or aluminium. A round permanent magnet is inserted into the bored hole and a handle is attached to allow easy rotation of the magnet. This act of rotation changes the direction of the magnetic field so that it is either directed into the two halves, where the iron blocks act as keepers (off position), or directed so that the field traverses the non-ferrous material between the two halves (on position).
In this on position the field is effectively passing across an air gap where it can be made to do work, if this gap is bridged with another piece of iron (or steel in our case) it becomes part of the magnetic field's circuit and will be attracted with the full strength of the magnet, this is the work we want it to do—clamping.
A magnetic base can therefore be attached in a variety of positions to any attractive surface, allowing the base to be positioned in the best orientation for the part to be tested. Combine this with the flexibility of movement allowed by the arms gives the operator a large range of options in positioning the dial indicator.
An alternative to the post and swiveling connectors is an arrangement whereby a series of interconnecting swivels can be set in position by tightening or loosening a central member. This member may be made from wire rope as it has to be extremely flexible yet strong in tension, the possibilities for positioning this type is probably no more than the two post type but its advantage lies in the fact that there is only one mechanism (screw) to loosen or tighten the arrangement making it easier to use, unlike the other where a third hand is often wished for.
Metalworking Tools Cutting machines Cutting tools Forming tools Hand tools Machine tooling Measuring instrumentsBore gauge · Caliper · Center gauge · Comparator · Dial indicator · Engineer's blue · Feeler · Gauge · Gauge block · Go/no go gauge · Height gauge · Machinist square · Marking blue · Marking gauge · Marking out · Micrometer · Radius gauge · Scale · Sine bar · Spirit level · Straightedge · Surface plate · Tape measure · Thread pitch · Vernier scale Smithing tools Casting · Fabrication · Forming · Jewellery · Machining · Metallurgy · Smithing · Tools and terminology · Welding
Wikimedia Foundation. 2010.
Look at other dictionaries:
Base Magnetic Island (Magnetic Island) — Base Magnetic Island country: Australia, city: Magnetic Island (Nelly Bay) Base Magnetic Island Location Located on Magnetic Island, only minutes by car from the ferry landing. 20 minutes by ferry from Townsville to Magnetic Island, regular ferry … International hotels
Base Backpackers Magnetic Island — (Nelly Bay,Австралия) Категория отеля: Адрес: 1 Nelly Bay Road, Ne … Каталог отелей
Magnetic stirrer — A stir bar mixing a solution on a combined hot plate magnetic stirrer device. The left knob controls the stirring rate and the right knob controls heating. Other names Magnetic mixer Uses Liquid mixing Inventor … Wikipedia
Magnetic nanoparticles — are a class of nanoparticle which can be manipulated using magnetic field. Such particles commonly consist of magnetic elements such as iron, nickel and cobalt and their chemical compounds. While nanoparticles are smaller than 1 micrometer in… … Wikipedia
Magnetic Surveying in Archaeology (book) — Magnetic Surveying in Archaeology (Wormianum, 2008, ISBN 978 87 89531 29 8) is a book written by Russian archaeologist T. N. Smekalova together with O. Voss and S. L. Smekalov. In the book researches collected information about magnetic… … Wikipedia
Magnetic Island — with Townsville suburbs in the foreground Palm Islands location Geography … Wikipedia
Magnetic island — Magnetic Island Géographie Pays … Wikipédia en Français
Magnetic flux leakage — (MFL) is a magnetic method of nondestructive testing that is used to detect corrosion and pitting in steel structures, most commonly pipelines and storage tanks. The basic principle is that a powerful magnet is used to magnetize the steel. At… … Wikipedia
Magnetic Island — Géographie Pays … Wikipédia en Français
Magnetic semiconductor — Magnetic semiconductors are semiconductor materials that exhibit both ferromagnetism (or a similar response) and useful semiconductor properties. If implemented in devices, these materials could provide a new type of control of conduction.… … Wikipedia