CNC machinery is excellent for industrial manufacturing, this website should be a testament to that fact, but did you know they can also be used for personal projects and one off custom jobs with ease!
In this post we'll be cutting three layers of 25mm Ethafoam to safely transport a custom assortment of photography equipment in a 75mm deep hard case.
The foam will be cut using a bayonet mounted reciprocating cutter with a serrated blade.
First, we start with creating a Computer Aided Design (CAD) file. If you're not familiar with CAD, don't let this put you off. Some tasks can be deceptively simple and there are many tools and website available that will help you.
In this case, we used Vectorworks 2019 to make a simple 2D drawing. I won't go into the specifics of creating this particular drawing, we'll probably get to that in a future post.
As we'll be doing a Vectorscript export, the colours for each element or path will be important.
In the image below you can see the magenta outline, this matches exactly with the interior of the camera case as your cut will be so precise (0.3mm) you can use the exact dimensions.
If you're lucky you might find these dimensions or even a CAD file online, but in our case we had to measure.
Black denotes the objects we're designing the camera case for. In Tangent's or DXF AAMA terms, these will be interior cuts.
In this scenario, we have a Leika camera, a handful of lenses and a couple of lens hoods. None of these shapes require any special tooling or settings, so we can leave them all as the same path type.
For the last path type there are some (hard to see against the white background) yellow circles. These will end up as thumb holes to help with removing the camera components from the case.
As we're cutting the total 75mm depth in three 25mm sections, we'll only want the thumb holes on the top layer, so using a different path from the other internal cuts will make selecting which paths we want cut for each layer much easier.
When we have everything measured and placed in Vectorworks we select the lot and group it. This tells Tangent and other CAD and CAM software that each element is related and to treat them as a whole.
Finally, we're ready to export. As I mentioned previously, we'll be using Vectorwork's Vectorscript export. There's no options for this, so you only need to name the design and save it somewhere easy to find.
Next up, importing to Tangent.
Thanks to the work done in Vectorworks, there isn't much setting up to do in Tangent.
When you select import, Tangent will display the screen below which tells us that our paths have imported as we specified.
Next we set the parameters that the tools assigned to these paths will use. The below screenshot shows that we've set the reciprocating blade to travel at 900mm/s with an acceleration of 1,400mm/s².
This type of foam is easy to cut, especially with a reciprocating blade, so we can use fairly high speed settings.
If you see yourself cutting more of any material in the future, these settings are saved as part of the template to be recalled easily in the future.
We're almost ready to cut, so press ⌘ + P to bring up the cut window pictured below.
It's very important that paths are cut in the right order so as to prevent pieces becoming loose after cutting.
To that end, we're putting the magenta / envelope / outline path last. The order of the other two paths doesn't matter much in this case, but we do want to minimise the chances of anything moving by cutting the exterior last.
In Tangent, reordering the paths is very easy, you only need to click and drag the paths into the desired order.
As we're only cutting with a single tool, each path will be using the reciprocating cutter in a bayonet holder and the single speed and pressure we set up earlier.
Once that's all set and checked, it's time to cut! You can see how that plays out in the video below.