Anyone who has tried to clamp an irregular part in a standard machine vice knows the problem. Hard jaws crush, mar or simply refuse to grip a curved or fragile workpiece. Soft jaws, custom jaw inserts shaped to the part geometry, have been the answer for decades. Traditionally machined from soft aluminium, they are now overwhelmingly printed.
Bespoke vacuum fixtures sit in the same category. Both have been transformed by additive manufacture, and both deliver workholding that used to be the preserve of high end production shops. The questions below cover the ones we field most often from Australian machine shops and fabricators.
Are printed soft jaws actually strong enough for production?
Yes, for almost any finishing work and a large share of roughing. A jaw insert printed in PA-CF or PA-GF can support cutting forces equivalent to traditional machined jaws across most milling operations. Heavy roughing on tough alloys may exceed the envelope, but finishing operations almost never do. Heat set inserts handle the fastener interface to the standard jaw body better than printed threads, which lack the durability for repeated mounting.
Which materials should I print them in?
PA-CF is the default for stiff, dimensionally stable inserts on most prismatic work. PA-GF handles parts where impact tolerance matters more than absolute stiffness, including soft alloys, composites and parts with sharp interrupted cuts. PETG-CF is a budget option for light load jobs and short runs. We source most of these grades through OzFDM, which keeps batch properties consistent and traceable across a production run.
How does vacuum fixturing work with AM?
For thin, flat or compliant parts including sheet metal, composite layups, electronics housings and soft polymers, vacuum fixturing is often the right answer. AM is excellent for the upper plate of a vacuum fixture, because the plenum geometry, port routing and gasket grooves can all be printed in a single piece. We typically print the upper plate in PA-CF for stiffness, with a TPU gasket either co printed or fitted after the build.
What about gasket sealing and porosity?
Layer line porosity is the main enemy of a vacuum fixture. We address it by ironing the top surface during the build, glass bead blasting the sealing face, or applying a thin epoxy skim across the gasket groove. Done well, a printed plate holds vacuum as well as a machined aluminium one, at a fraction of the cost and a fraction of the lead time.
How fast can I get a set?
The turnaround on standard jaw insert work is typically 24 to 48 hours from approved CAD, with vacuum plates taking a little longer because the gasket and validation add a step. For repeat work the printed jaws stay on the jaw bodies indefinitely. For one off jobs they are effectively disposable, which is part of the appeal.
Send the workpiece, not the jaw drawing
We design jaws faster from the part to be held than from a sketch of a jaw. A STEP file of the workpiece, the vice details and the operation list lets us return a printable jaw design in hours. Talk to our CNC team for any tooling that spans both AM and conventional machining.