Workholding basics - How best to set up your job

The most common type of workholding is a standard machine vice.

Size and shape of your component are the most important factors in the choice of vice (with vices ranging in size to accommodate up to 200mm width of jaw).

For example, if you have a square or rectangular part that will fit in a vice quite easily, then a standard machine vice would be the simplest form of clamping onto a machine bed.

It is also possible to clamp round parts in a vice using special jaws.

A fixed jaw vice involves having a single jaw move into a fixed jaw, which when tightened applies the clamping force.

Because the jaw is fixed, you can use this as a datum edge (you’d run a clock along your fixed jaw to make sure it is parallel and square, then put your part in and clamp it up with a single jaw – the moving jaw).

When you’re machining larger component sizes, you will want to start using clamps to clamp parts into the machine bed itself.

The part that you are machining will determine the type of clamping system you use.

Depending on the complexity of the part, you can clamp from the top of the component or use pull down clamps to hold the component lower on the machine bed.

This is useful when you want to machine totally around the diameter of the part, or around the periphery of a square for example.

This style of clamp operates on a similar design as standard top clamps - in that they are held in place by T-nuts on the machine. Because of their taper design, when clamping forces are applied the clamp slides down against that tapered edge, pulling the components down to the machines bed.

Another commonly used workholding technique is to use something called zero-point fixturing.

This style of clamping lends itself to 5 axis machining, but it’s not limited to this.

Because of the design of this fixturing, it not only makes accessibility a breeze when machining, but also repeatability.

The system usually works off a self-centring design, meaning that both jaws move centrally to the base of the vice and are held in place and located by studs in the base of the vice. These studs marry up with a base plate fixed to the machine bed.

This makes for quick set up times, but also allows multiple setups to be achieved on a single machine, maximising your machine efficiency.

MSC has partnered up with 5th Axis workholding to offer a suite of configurations for any machine setup.