Manufacturing is subject to the same pressures as any modern business: the need to increase speed of operations and maintain accuracy in the process; in other words, constantly striving towards greater efficiency.

Tool advancements are an enormous part of what increases a shop’s efficiency. For a long time, part changeover requirements were either infrequent or nonexistent. Now, plenty of manufacturers produce smaller batch sizes in order to meet customer demands that change frequently or unstable market conditions. Setting up a machine to run a new part number is something a machinist might have to do several times a day, so it has to be something that can be done quickly and accurately. This isn’t as simple as it sounds.

It can take anywhere from 20 to 30 minutes for an experienced operator to prepare a traditional workholding assembly for the production of a new part. And there are plenty of factors that can get in the way of a speedy changeover: the awkward position an operator has to hold in order to access the work envelope, the potential to drop slippery wrenches or tiny fasteners, making sure each component is clean and lubricated. All of the steps in a changeover have inherent pitfalls, but none more so than ensuring the cleanliness and lubrication of the new part: even tiny amounts of residue can cause runout in the arbor and improper lubrication can cause fretting corrosion and may lead parts to seize up or fail, causing catastrophe. On top of all this, the operator needs to be experienced enough to make sure that the standard workholding accuracies and repeatability are met.

A modular workholding system can reduce complexity and improve efficiency during the changeover process. In some cases, even an inexperienced machine operator can change out the workholding from one part type to another in 60 seconds.

Here’s how it could work:

One of three standard base units is mounted to the machine’s spindle during a one-time installation. It’s trued to zero axial and radial runout and permanently locked in place with torque mounting bolts, basically making it part of the spindle. The compact base unit is designed to exceed the stiffness requirements for operations that exert significant machining forces, such as deburring and chamfering.

The operator next installs a part-specific collet module, for either expanding or contracting applications. Lowering it onto the base unit, the operator fits the module’s retention knob over the base unit’s gripper fingers, and aligns the three internal clamp lugs. The installation is completed by turning the removable activation handle clockwise, which causes internal clamp lugs in the base to engage with the module’s retention knob, pulling the module down and precisely centering it with the taper built into the tooling. The gripper fingers pull down to securely lock the module in place and the handle is removed. A gear or pinion blank (or line gage) is hand loaded, and then chucked/de-chucked to fully seat the module.

Find out how JF Berns can improve the productivity of your shop. Give us a call today or fill out our Easy Quote Form today.

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