Looking for a waterjet manufacturing “expert” who can provide me some advice for a couple fabrication issues i’m having with the industrial jet I am using for parts fabrication this season.
I’m using an OMAX brand jet (>20 years old, don’t know the model).
I’m trying to cut 3mm-4mm pre-cured carbon fiber plate (photo below of the part I attempted today). The machine allows me to select the material and thickness (which drives the pierce duration and cut speed), and I also specify “Brittle Material” (which, I believe, increases the garnet ratio in the water stream).
It seems that piercing results in delamination on the top side of the material, and in some cases chipping on the bottom.
I did manually adjust the lead-in distance to hole cutouts, but for 3/16" diameter holes, there isn’t much space to lead in.
Does anyone have any tips or tricks to minimize delamination and pitting?
Can you adjust your piercing pressure? The pics look like it’s too high. I don’t have an Omax - I have a Flow. I’d try something in the 10000 - 12000 psi. Maybe even less. You can also try putting a sacrificial material on top and on bottom of the carbon fiber. Lastly I’d try having the carbon fiber just barely submerged or partially submerged. That and making sure the work table is flat. If your metal cross pieces are too far apart or are not consistent in height, the thin material is likely to flex or move or not have the support necessary when the jet exits the material. Worst case Omax may be able to help you with settings.
A suggestion I got a few weeks ago was to put a layer of aluminum tape on the top and bottom of the carbon.
I do set the OMAX to lower pressure but I don’t know if I can specify an actual pressure vs just using the “low pressure” option. I could try to lower the compressor’s output pressure by half as well and see if that works, though!
Piercing from outside cuts, we do at least 1/2” lead in.
Inside cuts hard if hole cuts are too small.
We’ve done this before with success if there is at least 1/2”.
