Edge Quality & Taper & Feedrate - Oh My!

Have you ever been curious about cutting a more definitive edge along your material?
Had to deal with that pesky partial cut that is 90% of the way through the material?

It is likely that the feed-rate, or the speed in which the cutting head moves along the pathing, is a touch too fast. The idea is to move the cutting head at just the right speed - the ever elusive sweet spot.

Depending on a large number of variables (mostly that of the feed-rate & material composition) every water jet will end up with a taper.


  • V-Shaper Taper: This is likely the most common taper a water jet user will experience. As the jet slurry takes longer to cut the bottom side of the material, the top side begins to erode a little more than the bottom.
  • Reverse Taper: This is a less common occurrence than the V-Shape. If the jet slurry is too slow it can result in the bottom of the material eroding away a bit more than the top. (Think of the water stream getting wider the further it travels away from the nozzle tip)
  • Barrel Taper: This is the least likely taper you will experience. Typically this has less to do with the jet slurry, and more to do with the material. If working with a composite in which the center is easier to cut/erode, the center will begin to erode away before the top and bottom are fully pierced.

Eliminating the taper is the name of the game, but unfortunately that is next to impossible - Eliminating is the wrong word. Every water jet will likely end up with a taper due to the nature of the water jet erosion process. So instead, the game becomes how to minimize the taper between top and bottom surfaces.

To do this, the default feed-rate for the WAZER created WAM materials are tested thoroughly and multiple times across multiple sheets of the same material. This is to gather the average feed-rate for the average edge quality. Once that has been determined, setting a speed rate above and below that creates a quick setting for the Coarse, Medium, and Fine cut qualities.

When cutting, if you are looking for the best edge quality it is best to slow the cut down enough while aiming for the sweet spot - minimal taper. If you find a cut with poor edge quality, I recommend re-creating the cut file in WAM using the Fine cut quality in step 6 of WAM.

Another way to achieve this is to manually override the default feed-rate. Every default feed-rate is set to 100%, but to change this in increments of +/- 10% press the up or down keys on the UI Pad during the cut itself. By manually dropping the feed-rate to 70-80% the pierce and movement speed of the cutting head will slow down - this allows you to experiment with different feed-rates as you dial in the exact edge quality you are looking for!

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