Printed tooling: jigs, gauges and soft jaws
The most profitable use of a printer in a workshop: drill jigs, go/no-go gauges, soft jaws and fixtures that save hours.
If you had to pick one 3D printing application that pays for itself, this is it. A jig is not sold, is not seen and nobody shows it at a trade fair — it simply turns a four-minute operation into a forty-second one, a hundred times a month. And unlike a product part, it does not have to be pretty or last ten years: it has to be there tomorrow.
What gets asked for most
- Drill jigs: the part that sits on the workpiece and puts the holes in the same place every time, with no marking or measuring.
- Go/no-go gauges to check a dimension without picking up a caliper. Anybody on the team can use one and nobody argues with the result.
- Soft jaws to hold a delicate or awkwardly shaped part without marking it.
- Cradles and assembly nests: the part sits in its recess, correctly positioned, and both hands are free.
- Spacers, stops and shims to set a machine or repeat an exact gap.
- Bench organisers and tool holders made to fit your tools, not a catalogue’s.
- Marking and positioning templates for assembly, labelling and inspection.
Designing tooling is different
- 1Make it foolproof. If the jig only fits one way round, nobody can put it in backwards. An asymmetric chamfer, or a stop that fouls if you rotate it, is worth more than an instruction taped beside it.
- 2Put a metal bush where the drill enters. Plastic wears fast under a spinning bit; an embedded steel bush multiplies the jig’s life.
- 3Print the name and version onto the part itself. An unlabelled jig ends up sharing a drawer with its previous version, and somebody will use the wrong one.
- 4Order two from the start. A jig used daily gets broken or lost, and the day it does, production stops. The second unit costs very little more.
- 5Do not expect metrology precision. A printed jig positions and repeats well; it does not replace a calibrated standard or certify a dimension.
The sum that justifies it
No spreadsheet needed. Count the minutes the operation saves, multiply by how often it runs in a month, and compare with what the part costs. In most cases the jig has paid for itself in the first week, and everything after that is profit. It is why a workshop that starts by ordering one jig ends up ordering twelve.
Which material suits a workshop jig?
Carbon fibre PLA by default: stiff, stable, and it does not distort with use or with a workshop’s summer heat. PETG if the jig has to flex or snap into place. TPU if it has to hold a delicate part without marking it. And wherever metal rubs — a drill, a cutter — an embedded steel bush, because no plastic survives that.
How do I know whether a printed jig will pay for itself?
Count the minutes the operation saves, multiply by how often it runs in a month and compare with the price of the part. Nothing more is needed: in most cases the jig has paid for itself in the first week. If the operation happens twice a year it does not pay; if it happens a hundred times a month it pays for itself.
Can I use a printed jig to verify a dimension?
To sort good parts from bad at the station, yes: a printed go/no-go gauge does that job and anybody can use it without interpreting a reading. What it is not is a calibrated standard: it cannot certify a dimension or back a dimensional report, because the gauge itself carries the tolerance it was printed to.