Waterjet cutting prices are based upon the following:
- Setup time
- Material
- Machining time
Setup time includes the time to load the stock material on the waterjet machine, process and transfer the cutting program to the computer controlling the machine, and so on.
Material is the type of stock from which your part is made. Some materials simply cost more to obtain.
| Generally more expensive per square inch < |
Generally less expensive per square inch > |
||
| stainless steel | aluminum | steel | acrylic |
Thicker material generally costs more than thinner material per square inch. The harder and thicker the material is, the take longer it takes to cut.
Machining time is just the amount of time that the machine has to run in order to make your part. The longer the cutting time, the more wear and tear on the machine, and the more electricity and other consumables that must be used.
Factors affecting machining time
Thickness
Keep in mind that it takes a lot longer to cut through 1/2 inch steel than it does 1/4 inch steel. 2.3 times as long, in fact; not twice as long as you might expect. Thus, you should possibly consider the stacking technique for thicker material. This means cuting two pieces separately, then fastening them together into one thick piece. In the case of a ½ inch thick part, you would stack two ¼ inch pieces to get the correct thickness.
Material type
Softer materials cut more quickly than harder ones.
| < Generally hardest to cut | Generally easiest to cut > | ||
| alloy steel | steel | aluminum | polycarbonate |
Convex and Concave Corner Design
Sharp inside (concave) corners and tight arcs are take longer to cut and will drive up the cost of your part. The sharper the corner and tighter the arc, the harder it is to make. Note that sharp outside (convex) corners are generally faster to cut than outside curves or arcs, due to a waterjet cutting technique called corner passing. However, rounded inside corners are often less expensive to cut than sharp inside corners, as the waterjet does not have to slow down as much.
Illustration : More expensive: rounded outside corners and sharp inside corners
Illustration : Less expensive 1: sharp inside corners
Illustration : Less expensive 2: round inside corners
Internal Holes
Every internal hole you add to your part means that the machine has to do extra work to cut each one out. The waterjet cutting head must traverse to each hole location and pierce the material before cutting around the cutting line. With fewer traverses and pierces, machining time is sped up.
Illustration : More expensive: more internal holes
Illustration : Less expensive: fewer internal holes