Introduction: 3D Printed Waterjet Work-holding for Thin Parts

About: An Engineer with an Aptitude for Technology and its application. A Tinker and a Maker, taking things apart and putting them back in a better way.

The Problem

Waterjet cutting is a 2D process by which material is removed through accelerated erosion by water and abrasion. There are minimal cutting forces exerted on the material, as the water slowly erodes the material. But the high-velocity water draws a lot of air along with it which can rise up and float the material sideways.

This is mainly a problem for thin materials as heavier materials are held up by their weight. The most common way to clamp a workpiece is by using a square on one edge of the tank and using clamps to press it to the square. This has two problems,

  • When the material is cut the structural integrity of the material fails, if the location and magnitude of clamps are at critical locations then the work is compromised.
  • Clamping thin sheets of metal against a square is nontrivial and it might bend in the middle. Clamping all the edges vertically might be more useful.

Some good fixturing ideas

Solution

An easy way to clamp the work would be to clamp them vertically to the slats of the machine, granted the slats will flex a bit and not great for accurate positioning, but it can be mitigated for slightly large surface area workpieces and when clamping on multiple slats.

A 3D printable clamp was designed to clamp thin materials to the bottom of the slats.

Step 1: Iterations and Print Parameters

Some images of the previous designs, the space between the slats are limited, hence a convenient way to remove the clamps was to project a small tab towards to top which allows the clamps to be easily removed with fingers.

Print parameters

Clamps are consumables that need to be replaced as they are worn. They are economical to print in multiple copies.


Print time: 31 mins

Material: 9 grams

Layer height: 0.35mm

No supports