There’s no doubt that cnc foam cutters are cool. I remember back in my university days having to fashion our own diy foam wire cutters (non-cnc of course) to cut through large blocks of foam for our boating projects. These were typically constructed with cheap wooden frames (a lot of time using custom wood/ mdf) with butterfly screws to tighten a hot wire across attached to a transformer.
Nowadays things have gotten extremely fancy with the new wave of cnc hot wire foam cutters that now make our diy back-in-the-day efforts pretty old-school. I wanted to set out to find and put together a cnc hotwire foam cutter myself to see just how much more awesome a cnc equivalent is and what the costs are associated with this. So here is what I ended up doing for this little diy project:
Step 1: Parts
The primary sources I used were Amazon and Home Depot. I found a few good instructions online and narrowed it down to the following:
- 9v-12v switching adapter, at least 1.3 / 1.25 amps as an output
- Something for a frame – I went with custom wood/ mdf, screwed together to make a frame.
- Guitar wire .10 to .16 size works well
- Butterfly screws
Step 2: The build
Building a foam cutter isn’t too hard. The biggest thing to think about is the size at which your EPS, XPS or EPP foam is going to be. Once you have this one of the biggest things people tend to forget about is the flex in the frame. The wooden frame I made did flex a few times causing the wire to move smooth in some areas and not so smooth in other areas. Adding some extra plastic reinforcement to reduce flex really helped out here.
Once you have the manual cutter itself it is time to hook this up to a cnc machine. You’re going to have to do your research depending on the type of cnc foam cutter software you use, as the baseline set-up would be different for ever machine. I managed to mount mine on a 3 axis cnc machine and programmed the software to account for the space between the drill part and the hot wire.
With the above set-up I was able to cut some basic shapes, shapes that have wooden templates as a guide as well as some wing shapes for hydrofoil testing. This was a bit of a hap-hazard build so I thought for my next build I would look into some sort of cnc foam cutter kit set, or some plans to give me better direction and save the headache of mounting anything too diy onto an actual pre-existing cnc machine.
The best resource I found was RCFoamCuter.com (for the diy spirited hobbyist). They have a few kit-sets that would really help someone who has zero prior experience get started.
However after going through the hassle of diy, sometimes just buying a machine outright makes a lot of sense. I am reminded of one of my co-workers who went back to his iPhone after constantly installing custom roms on his Android – sometimes it’s just easier to pay the money and move on knowing everything will just work without constant tinkering required.
So where are the best hot wire cnc foam cutters for sale?
It depends on usage. For smaller cutters, the RCUniverse forum is great. For larger machines the CNC Zone classified page is a good place to start for used machines. For brand new machines CNC-Multitool.com has some solid 4 axes cnc foam cutting and milling machines.
Alibaba is also a great place to look as many hot-wire foam cutters are generally brands that are lesser known – so it is best to go straight to the manufacturer in this case. At a quick glance many sellers/ manufacturers on Alibaba do allow you to order just one of their machines.
As always I always recommend you do your own due diligence and research as buying and operating a machine that is not fit for your project needs or skill level could be a disaster. Also the feeling of getting a diy wire cutter up and running or seeing a new cnc machine run its first test run is always great. Good luck!