Partial cut (scoring) on purpose?

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Has any one ever done a partial cut on purpose? I had the idea of doing a partial cut to help control a bend and get a clean, small radius bend if you didn’t have proper bending tools.
I was doing this with .075" 420 stainless and has decent success. Here’s a brief rundown of what I did, sorry I don’t have pictures.

  • Ran the General Cut on a sample of material to get cut feed rates and partial cut feed rates for different depths.
  • CAD’d a 2"x.5" rectangle with lines at each .5" distance.
    -Imported DXF into WAM. Luckily, the interior lines on the DXF are always generated on center, regardless of the cutting path selected. You can see this in the picture which is the Outside path, but the interior lines are still on center.
    image
  • Generated the GCode and opened in in NCviewer.
    -Edited the GCode to move the 3 interior paths at the end of the file and changed the feed rates for each line so they wouldn’t cut all the way through. I made an educated guess on the feed rates based on the sample cut earlier. I picked feed rates that didn’t have the path wander due to blowback from the jet.
  • Cut went just as planned.
  • The deeper partial cut was quite easy to bend in a vice with a pair of pliers and stayed nice and tight to the line.

In general, the deeper the partial cut, the easier it is to bend the material, obviously. A partial cut also weakens the material so the bend won’t be as strong as full thickness, again obviously.
This method seems to work well if you don’t have a bender, or your bender can’t handle the thickness or strength material you need.

Anyone have thoughts on partial cutting? I’m new to water jet cutting, so I’m experimenting to see how I can get the most out of the machine. Next up is an even faster feed rate in order to get more of an etch and be able to write text.

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So, this is all theoretical…because in the whole warranty thing, they say that editing Gcode will void the warranty and using the machine for engraving will do the same…

So, theoretically, yes, this works fine. There are stories of using a waterjet to deburr very difficult features using a very fast feed rate. I would say that depending on the material, you should switch to the lower flow abrasive nozzle in the hopper. That way, less abrasive is shot out. However, this waterjet is inconsistent in both abrasive rate and path wandering…

Anyway, this is a solid idea if we could edit these things in the software. Otherwise, totally theoretical…

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The method you used is smart. You can also make 2 gcode files: the first one do the partial cut, then the second one cut the part off.

When there isn’t a bending tool, my method is to cut some short segments along the bending line to weaken the material.

cut
cut574×640 111 KB

bend
bend540×640 91.4 KB

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I also thought about doing the segmented (perforated) cut, but the bent area I needed was less than .5" long and I didn’t want the extra kerf around the pierce.
I also did the score cut after the through cut so that I could turn on the nozzle while it was over the previous cut kerf. I did that to try and avoid blowback and drift.