One of the first things you’ll discover as a beginner is the tendency for chuck jaws to dig into the workpiece. Jaws are hardened steel and will leave a mark on just about anything you put in them – especially if the part spins. So how do you keep the jaws from marring your work? Some nicer chucks come with jaws that allow you to attach aluminum soft jaws to them.
Soft jaws have several advantages, especially when you need to hold a custom workpiece. For example, you can also make or buy a set of soft jaws and bore them out to the perfect size to hold the workpiece, and since you’ve bored them on lathe, the jaws will hold the part perfectly concentric to the spindle axis.
As you can see from above this can be especially helpful when you want to hold smaller parts made of soft metal.
But what about when you just want to hold a part without marring it? Are expensive/custom soft jaws necessary? NO!
Do you have a soda can lying around? If so you’re in business.
First, cut the can open (carefully) with scissors, and cut the aluminum into strips who’s width roughly match the size of you’re jaws. Make them long enough so that they can wrap around 3 sides of the jaw, and fold them around a piece of metal approximately the same width as your chuck jaws – my 6″ scale is perfect for this.
Next, slip them over the jaws. Folding them gives them a shape that allows them to grip the jaws – that way they stay in place – which is a lot easier than trying to slip pieces in around the part.
Finally, insert your part. You’ll be able to tighten the jaws a bit more than you would be able to normally, but the can is only about .004 thick, so you still need to be careful. Also, if the part spins replace the jaws – they wear through instantly.
I hope that helps! Obviously real shim stock (brass, aluminum, etc) would work as well, but aluminum cans are cheap – and you’ll be recycling at the same time!
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