|CNC foam cutting, the cheap and easy way
the X-mas hollidays of 2014 I spend some time discovering the
possibillities with foam cutting. So I could make a simple sign without having
to waste lot's of time. This because my machine isn't the fastest
CNC machine around. So cutting wood takes a lot of time, cutting foam
can be done a lot quicker. I noticed that EPS insulation foam (Expanded PolyStyrene) can be bought
very cheaply at the local hardware store, so this opens up a whole new
world. The fun is that you can make a large sign very cheap, quickly
and light. A good and fun example is also the project you see at the end of this page.|
Cutting foam isn't done with the router I use to cut wood, nope, I really don't like routers as the make a mess and lot's of noise. And since I don't have a decend method of cobering the machine, the entire workplace is covered in dust within minutes after starting the machine. Fortunately foam cutting can be done much easier. Hot wire cutting is a great example of doing this. But the problem with a hot wire is that is must go through your objects. So instead I go for a hot rod, something that can easily replace my router. And after lot's of thinking how I could make this, it suddenly struck my mind that I'm using such a device already almost every day. My trusty old soldering iron. This has a method of controling the temperature very accurately and it only requires me to make a special tip. Fortunately I have such a tip, which requires only a slight modification in order to use it. I modified the oldest and worst soldering tip I had (no problem since it was time to be replaced anyway) and by doing so giving it a new purpose, cutting foam. Modifying the tip was very easy, using my drillpress and a file to file it to the desired width. You could say that I used my drillpress as a lathe, always be careful if you want to do this yourself. This is only possible because soldering tips are made of very soft material (copper) and because my file was a very sharp one.
test used lot's of tie-raps to hold the iron to the machine. I wasn't
sure if the soldering iron was to heavy for this task, I experimented
with the temperature and settled for a point where the foam was molten
only slightly. I didn't wan't to burn it. So a temperature of 225
degrees Celcius on my modified tip causes a stable hole in the foam of
6mm. Allmost twice the size of the tip, which is great because the foam
melts before it touches the tip. But only when the speed of the machine
is set to move slow enough, since my machine is slow by default (it
just can't go that fast), this is no problem at all. the lable on the
machine says "CC1" which stands for Cheese Cutter 1, the design of
the machine was for very simple tasks. Although in practice it can cut
more dense materials then cheese, it still is a simple and low cost MDF
and ball bearing based machine. The Z-axis coupling is a rubber hose on
the photo, but has been replaced by a aluminum coupler I bought from an
internet shop for just a few euro's. This was a huge design improvement
because the hose coupler simply wasn't up to the task of moving a
router up/down for long periods of time. This because the stepper motor
becomes hot, resulting in the hose becoming hot. Making it less rigid
and harder to fix Z-axis to the axle of the stepper motor.
So now with the principle proven to work, it was time to make a simple holder for my soldering iron. Very important, because I need my soldering iron for soldering also, so it must be easy to place/remove from the CNC machine. So now you see, whith just a few simple actions, my CNC machine is converted (you could say downgraded) into a foam cutting machine. Fortunatley I can easily replace the soldering iron for the router and cut the designs into wood if I need to.
The IKEA lights now have reached their full potential. I like it, the simple old fence is now a lot less boring.