A leading British manufacturer of plastic bearings and gears, BNL replaced conventional wind-up vices on two Hurco machining centres at its Knaresborough factory in North Yorkshire in August last year. Not only are workpieces secured faster, but repeatability and safety are also improved.
Says BNL’s toolroom supervisor Chris Hargraves: “With a conventional vice, the movable jaw tends to ride up when a part is clamped, so you have to use a mallet to tap it down. Then you usually have to tap the handle to make sure the part is fully secured. We machine up to 50 plastic components at a time here and it was a time-consuming process that is no longer required with the One-Loks.”
He explains that the controlled clamping action produces a pull-down effect as the jaws close, so components are always seated firmly after the handle is tightened by hand. Positioning of the components is also more precise, so machining is more consistent from batch to batch.
As for speed, it takes anything up to a minute to wind the handle of a normal vice that might, if the jaws are wide open and a small part is being clamped, require up to 70 turns. By contrast, a ratchet system on the One-Lok allows the movable jaw to be quickly positioned to within a few millimetres of closure, with just a few turns of the removable swivel wrench subsequently required.
And as the Chick One-Lok system can use both hard and soft jaws but the previous vice system was only able to use hard jaws, issues linked to irregular shaped parts have disappeared. If parts were round, for example, only two could be clamped, as a third would undoubtedly not be secure, while there was also a risk of delicate surfaces being marked.
Machined soft jaws on the Chick One-Lok system can accommodate many such parts and, as the shape matches perfectly, they are held securely and without damage. And repeat job set-up is fast, since jaw sets are stored for re-use.
Finally, Hargraves highlights that the outboard hard jaws that can be used to extend the clamping range from 203 to 432 mm are useful as BNL produces aluminium fixture plates that make use of this feature.
