First cut
Preparing the file
The waterjet is a machine that can cut 2D parts out of flat stock material. To start you will need a DXF file (a 2D vector file) of the part you want to cut. The example for this tutorial will be a gear, found here
Several other 2D file types may be possible to import, like .svg files
Before we start with the software, we have to first decide what material we will cut this out of. This is a step that is not considered with additive manufacturing. I am using a .25” thick 6”x6” 6061 aluminum plate. I then have to fixture it somewhere on the cut bed.
The part must be fixed down because, unlike 3D printing or laser cutting, there is a significant amount of force applied on the material by the water and abrasive. If it wasn’t fixed down, the material would be flung around immediately.
To fixture the material, place it on the cut bed and use the provided screws to hold it in place. The screws will tightly screw into the holes on the cut bed and the heads should be on the top surface of the material.
Ensure that you are unable to move the material at all
Once you know the location and size of your material, you can start with the software
Go to wam.wazer.com and sign in with:
Username: mweldon@chapman.edu
Password: FowlerMakerspace1!
Start by clicking Import File under the File drop down and importing the dxf
It may come in small, so we will have to scale under the Scale and Position dropdown
Make sure to click on the gear to be able to scale and move it. I changed it to a 2”x2” gear
The grid displayed in the software is the same as the grid on the cut bed
I know my material is placed over the middle four blocks so I will place the outline of the gear in that area
Next, under the Material dropdown I will select Aluminum 6061 0.250in to match my material
On the Cutting Path dropdown, click on the gear to select it, and decide whether you want it to cut directly on the line, inside or outside.
Because the nozzle diameter is not infinitesimally small, the width of cut is about 1.2mm so your part may come out smaller/bigger than you expect if you cut on the centerline.
Next we will use the Tabs and Leads dropdown.
A tab is a small connection point between your part and the material from which it is being cut. It’s designed to keep your part in place for the duration of the cut. Because there is so much force on the material and part when cutting, as the part is almost fully cut out it will wiggle around a lot and cause the cutting to be less accurate.
A lead refers to the distance that WAZER will be cutting away from the cut path. This is done to make sure that the oversized pierce at the start of a cut does not remove any excess material on your part.
I kept the leads enabled and added 3 tabs. I typically do not change the size of the tabs unless I have already tried cutting it out and it does not hold. I normally would do manual tab placement but for this part I wanted to make sure the tabs were on the outer end of the teeth not the inner end.
On the final Cut tab decide what cut quality you want. Unless it is something that requires a very fine cut, it is preferred to select coarse as it will save time and abrasive.
Lastly click Generate Job File and save it to the SD card using an SD to USB converter
Starting the cut
Now we go over to the machine and place the SD card in the slot
The LCD screen will look like this:
Using the arrows and ok button, click Select Cut File and then click the name of your cut file, then click Yes when prompted
The screen will take you through a series of prompts to prepare the machine for cutting. It will first ask to lift the nozzle clear of obstructions.
To do so, you will loosen the large knurled silver knob and push the nozzle up to a height where it will not crash onto anything on the cut bed
Then click OK on the screen and the nozzle will move to the back left corner
The screen will then ask you to verify your material, assuming that you selected the correct material, click OK
The screen will next ask you to fill abrasive and empty used abrasive. Unless you have a very long cut you will probably not need to fill additional abrasive. Ask for a staff member’s assistance if you need more abrasive. If the tank looks like there is a lot of used abrasive sitting in the water, notify a staff member.
You can pull out the drawer on the right side of the machine to check the amount of abrasive.
It will ask you to fasten the material to the cut bed, which we have already done so press OK.
Now it wants you to set the nozzle height. The nozzle is required to be a certain distance above the material to cut properly.
Begin by using the arrows to jog the nozzle over the material
Then remove the cap on top of the nozzle
The cap has a little lipped section that is the exact distance from the tip of the nozzle to the top of the material that the nozzle should be placed.
Under the rubber cover (don’t take it off) the nozzle looks like this:
That little tip is what we want to fit onto that lip on the cap to offset the distance correctly
Use the silver knob to adjust the height of the nozzle so it is on the lip of the cap. You will have to move the cap around to feel if it's appropriately placed.
Once that is done, replace the cap on top of the nozzle so we don’t lose it
Then press OK
Now we have finished preparing the machine for cutting and we have several options. The first thing we want to do is select Check Cut Extents. This will have the machine move around the outline of our cut to ensure that it will actually cut above the material. If it is off, you will need to redo it in the software.
Once you have verified that you will be cutting in the correct spot, select Cut Material.
The machine will now begin preparing to cut. As a reminder, if anything bad happens, like your material wasn’t fixtured properly and is flung around, stop the cut on the screen. If it is an emergency and needs to be stopped immediately, press the big red emergency stop button
When the machine first begins to spray water, it will spray outwards until it punctures the material. This may take a couple of minutes
In the above pictures, the material wasn’t punctured until the last picture. Ensure that the material is actually punctured before the waterjet starts moving around.
You don’t have to stand right in front of it, but stay close by until the cut is done.
After it is finished, remove the screws to take the material out of the bed
To remove the part from the tabs, you typically have to wiggle it around a bit until they break. Make sure to file off the bits from the tabs because they are sharp.
