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17-08-2007

Bad copies - Happens with vibratory equipment too.

Sometimes copies of vibratory equipment or drives can create trouble, as some details are not easy to copy.

The vibratory cells developed by former partnes Uhde GmbH from Germany and build in Brazil since 1989 are a standard of quality.

Nowadays similar products are being marketed in Brazil, of sometimes unknown or obscure origin, obviously a lot cheaper.

But the copies tend to create some problems, as the materials quality is not always analysed when faking the original. Gears loose their shape, cracks appear, badly manufactured roller bearings tend to brake apart.

The natural frequency vibratory conveyor for example is a specially designed product and the relation of masses and number of springs (flat and coil) is determining for the optimum operation.

The computer assisted calculation has managed to streamline longer machines with smaller drives, saving energy. Not easy to copy, despite some unfruitful attempts.

Know-how are the words.

1 Gear pair too small may cause teeth-splitting headaches...Bad calculations or just an "economic" copy.
2 The size relation gear/shaft is a little thin. After 3.500 running hours the competing drive stopped running.
3 Bad copy of a Mavi Revitran conveyor, made with lesser information than required, for 1/3 the value. The pan started cracking, the mass and number of springs relation was unbalanced, an attempt to include more coil springs was unfruitful. The mach
4 Welds start to crack on copied conveyors components.
5 Spiral elevator and cooler for synthetic rubber crumbs cracking away after 3 month running time. Emergency welds could not stop replacement.
6 Too thin. Customers are not always aware of the material´s gauge importance and go for the cheaper, with original manufacturers as far away as Bulgaria. The equipment becomes a nightmare. Cracks everywhere, no technical assistance.

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