Centre Lathe Chucks
A Chuck is a type of clamp usually designed to hold round objects. You will have used one to hole a drill bit in a pillar drill for example. On the Centre Lathe there are several different type of 'chuck' that can be used:
3 Jaw Chuck
A 3-jaw chuck is hold round bar securely so that it can be machined. The chuck is mounted at the headstock and driven by the lathe motor so that it spins. The 3 jaws are 'self centring' which means that when the chuck key is turned all 3 jaws move together makign sure that the bar is head in the absolute centre of the chuck.
These chucks can only really be used with round or hexagonal material
Chuck Key
A chuck key is the tool used to loosen and tighten an object in a chuck. The key for a lathe chuck is different to a drill chuck and is usually square ended. This must always be removed before starting the lathe or it will fly out and could injure someone. Some keys are spring loaded so that won't stay in the chuck unless you are holding them.
4 Jaw Chuck
A 4-jaw chuck is used to hold non-circular work. Most 4-jaw chucks have 4 independently movable jaws so that they can be adjusted to hold items of uneven shape such as rectangles these can be tricky to set up as fine adjustments must be made to ensure the item is centred. Some 4-jaw chucks are self-centring so that they are easier to use but they can only turn even shapes such as squares, hexagons, etc.
This chuck has been set to hold a rectangular shape of metal
This video describes how to set such a chuck up
Jacobs Chuck
This is the chuck most often seen on a pillar drill or electric dril. The 3 jaws are self-centring and move together to grip drill bits or other round tools. On a lathe, these chucks can be mounted in the tail stock and used for centre drilling into or through the work.
Key-less chuck
Some chucks come without a chuck key which can make it quicker to change drill bits.
