Synchronization is required for spindle transfer of odd-shaped parts including hex and square stock and for round parts using live tooling on the main and sub-spindles. Without synchronized collets extra programming and cycle time are required to line up the workpiece to properly transfer the part from one spindle to the other.
In most cases (draw-in style collets) a keyway is used to align the collets when inserting it into the spindle. Synchronized collets orient the part to a specified point on the workpiece. Hex and square collets are synchronized to the center of the flat or the corner. Hardinge will provide a high tolerance of within 15′ or ¼°. Still greater tolerance can be achieved when required. Collets for specific machines such as Acme Gridley, Hydromat and other multi-spindle lathes that already have a keyway can be synchronized to the customer’s specifications.
ER collets are offered in many different types and offered in many different sizes. The problem is that if you’re not careful with your purchase, you may end up with a lot of machining issues. This is a classic example where you do get what you payed for….
To start, ER collets do offer a lot of range, most will offer a gripping range of a full 1 mm, but the TIR of your cutting tool may shock you. If you are using an ER collet to grip and drill a hole, then bore the hole, most likely you are ok. If you plan on running a spot, tap drill, and tap, the TIR issue can give you a lot of problems, and broke taps.
The problem is simple to solve with 2 suggestions.
Always purchase ER collets to size, meaning run a 1/8 ER with a 1/8 shank or 4 mm ER with a 4 mm shank, and avoid using that “gripping range”. This is just good common sense.
When you purchase the ER collets, ask for Precision or Super-Precision variety. They are available, and these offer TIR down as low as .0002 of an inch and that just may be what you need for that small hole, precision work…
Is your chuck-style cnc lathe not giving you the results you need? Ask about the Hardinge FlexC™ Collet System. It weighs less than a chuck so that you can take advantage faster feeds and speeds. It provides part length control and it has faster changeover time with improved concentricity. Hardened steel or emergency collet heads provide chucking diameters up to 2-9/16″
Posted by hardingegroup 