Mounting Work on Mandrels To machine a workpiece of an odd shape, such as a wheelpulley, a tapered mandrel is used to hold and turn the work.The mandrel must be mounted between centers and a driveplate and lathe dog must be used. The centers must be alignedand the mandrel must be free of burrs.
Rotifers: the wheel animalcules. Rotifers are microscopic aquatic animals of the phylum Rotifera. Rotifers can be found in many freshwater environments and in moist soil, where they inhabit the thin films of water that are formed around soil particles.ther animals with a pseudocoel, such as rotifers and acanthocephalans, appear to be more closely related to Lophotrochozoa, a large alliance of protostomes that includes molluscs, annelids, brachiopods, etc. Phylum Rotifera is divided into three classes: Monogononta, Bdelloidea, and Seisonidea.
Rotifers are small, mostly freshwater animals, and are amongst the smallest members of the Metazoa -- that group of multicellular animals which includes humans, and whose bodies are organized into systems of organs.delloid rotifers are the commonest variety found in fresh water. The term describes their habit of moving about by extending the body and attatching the head, then catching up with the foot and again extending the body -- bdelloid, like a leech.