Cut Internal Features on Existing Shape

In a normal operation, WAZER cuts the outer circumference after the interior features are cut out from a blank stock. The internal features and outer circumference are subjected to the same gantry coordinate system and ends result will be a very accurately placed internal feature relative to the outer circumference.

However, what if you have a material stock already in a pre-existing shape, which you want to accurately cut some internal features, what would you do?

This guide will teach you how to accurately cut internal feature in a stock material that has existing shape you want to keep.

Tools:

A piece of firm but cheap material
(For example, a piece of ABS plastic sheet)

Procedure

The general workflow is as follows:

Check gantry function
Cut out a fixture
Prepare cut files
Anchor cut material
Execute the cut

Check Gantry Function

This method requires two cut files. These two cut files need to have their gantry home point coincide.
If the home point of the first cut is different from the second one, your internal features will be cut inaccurately.

Please go to “Setup&Maintenance”> “Input.Output Check” > “Input” >”Limit Switches”. More information on this can be found on this page

Please pay close attention to the homing sequence. If you see the gantry jumping or jittering at either corner, please contact customer support for assistance.
After the homing sequence, we shall make sure the cutting head/nozzle assembly travel in perfect 45 degrees or 0 degrees. If you observe any other motion, please contact customer support for assistance.

Cut Out a Fixture

Lets take this piece for an example. If we would like to cut the internal features on a steel stock that has the exactly same dimension of the outer edge.

Please locate a relatively cheap yet strong material that can hold the steel stock firmly. Let's call it fixture material.
Then, use the dimension of the steel stock to make a cut file. Use "Inside Cut Path" in WAM.

After generating the g code, please leave the profile in the WAM, do NOT delete it. Take note of the X and Y coordinates, they will be useful.

Use the g code to make a cut out in the fixture material.
After the fixture cutting has completed, take the cut out piece, and leave the rest of the fixture material in the machine.
Now you have a fixture that can hold your material in place.

Prepare Cut File of the Internal Features

Origin and Bounding Box

First of all, we need to make sense of the "origin" and "bounding box" features.
In short, all features' origin in WAM is represented by the top left corner of their "bounding box". The bounding box is shown in WAM as the box made of dotted lines. The origin is displayed as "X Coordinate" and "Y Coordinate".
For more information on position and coordinate, please see this page

Prepare cut file on internal features

To start, please first measure the x and Y distance between the top left bounding box of the two internal features, to the top left corner of the steel stock. You may use the default measure tool in your design software to do that.

Then, delete the feature representing the steel stock. We are now left with the internal features.

Load the internal features into the previous WAM operation page. You will see the virtual cut bed displayed like this.

Look at the menu on the left, take note of the origin of the steel stock profile. If WAM is in different unit setting than your design software, please change the unit setting in WAM to match your design software.
In our example, WAM used to be in mm, while the measurement was taken in inches. Thus we need to change the unit in WAM from mm to inch.

Select the new dxf (internal features) we loaded. Add in the X and Y distance we measured to the origin of the steel stock profile.

In this case, X_internal = X_external + 1 inch; Y_interal = Y_external+0.4850 inch

You now get the precise and accurate location of the two features on the cutting bed.
Carry on the WAM operation. But this time, please select the steel stock profile and make it "No Cut".
"No Cut" is to tell WAM disregard the selected lines

Select the new profile, and make it "Inside Cut Path".

Normally when internal features are cut alongside with outer edge, you choose “outside“ cutting path to generate a true-to-size internal cutting. But in this case, the outer edge is not cut along side the inner features, we need to choose “inside“ cutting path to get a true-to-size result.
For more information regarding cutting path selection, please refer to this page

Carry on generating a cut file for the internal features.
You may visualize it by using the NCviewer.com. The instruction on how to visualize g code can be found here

Anchor the Cut Material

At this stage, you have the fixture firmly attached to the cutting bed. We can place the cut material onto the fixture.
Even if the fixture can snugly hold the cut material; we still recommend use screws to securely anchor the cut material further.

You may fasten the screw through the fixture material.
The top view of the layout is like so.

Execute the Cut

After the cut material is securely anchored to the cut bed, load the specially prepared internal feature cut file
Pay attention to the motion of the nozzle assembly/cutting head while it is traveling to the origin of the internal feature. If you see the cutting head fails to stop on top of the cut material, or close to the point you expect, please cancel the cut and start over.
After you feel certain the cutting head is on top of the internal feature’s origin, start cutting as you normally would.

Re-Cap

Once again, the general workflow is as follows:

Check gantry function
Cut out a fixture
Prepare cut files
Anchor cut material
Execute the cut