Why build a Hawker Hurricane in foam with a Hot Wire CNC foam cutter? Well as you may have noticed on my website I’ve built a Hot Wire CNC foam cutter and built several flying wings. So I was thinking about my next build and it had to be the Hurricane IID tank buster in Desert Air Force colours. I already have a Spitfire and Lancaster and had just recently read Leo Mckinstry’s excellent book on the Hurricane which inspired me to build one.
Building a model from scratch is quite challenging and requires a lot of research but I enjoy that and you sort of build an affinity with the aircraft. So that keeps me going when sometimes the motivation slides a little.
Do you need a Hot Wire CNC Foam Cutter?
The short answer is No. You can make foam core wings and fuselage sections without a CNC machine and many model builders do. I did before I built my CNC foam cutter machine for my Super VC10 but only for the wings and tailplane.
I used a gravity hot wire bow which pulls a hot wire over some airfoil templates. Works quite well with a bit of practice but making the templates takes a lot of time and you usually need one for the top and bottom of the airfoil which soon adds up. It could be argued that the time I’ve spent on the CNC machine is far more and that’s probably true. But now I can produce a wing in one cut and in about 20 mins. My third flying wing was a quick build after I crashed the first one through pilot error.
A good thread on RC groups on gravity hot wire foam cutter click
We need a plan
Firstly you need to decide what size aircraft you are going to build. Well, I wanted something that was a similar size to my Ripmax Spitfire for ease of storage and transportation so I settled on a 50 inch (1270mm) wingspan. There are quite a lot of drawings and CAD plans on the Internet for most aeroplanes. I always try to find a CAD drawing in DXF format which is an industry-standard which you can use one of the Free CAD programs to scale the drawing to your dimension. My favourite was DraftSight but it’s no longer free. LibreCad is available for free which looks very promising.
Profili2 Pro is quite an extensive program and has evolved over the years and can do lots of other clever stuff with airfoils. It has an option to generate g-code for 4 axes CNC machines and this is what I used for my flying wings. DevWing Foam 2 is the replacement for Profili. This is even better and well worth the cost in my opinion. Check my post here for details and tutorials DevWing Foam
Part 1 of the video in the list below shows the wings were made with Profili2 Pro, but you could have used one of the free options I’ve linked above
I used DevFus Foam to generate the g-code for the fuselage sections. Which is available in Demo version that is fully working apart from being able to save the g-code. www.devcad.com
Part 2 in the video list shows how to use DevFus Foam to make the fuselage
Part 3 in the list shows and the build progress
I’ve now created a video series on how to use DevFus Foam 2 to build the fuselage of a BAE Hawk with an electric ducted fan. Here’s a link to it https://www.rckeith.co.uk/getting-started-devfus-foam-2/
On the 7th of October 2018, she was ready for her maiden flight. I was quite nervous but reasonably confident she would fly well. I’d worked out with a 3000mAH 3S Lipo battery I would have 5 minutes at full power, but you don’t fly on full power all the time so I set 5 minutes on the timer. She was hand-launched, the undercarriage in the pictures is just for static display and is taken off for flight.
She leapt away and was a little lively until I got her trimmed and on lower rates, but she flies very well, what a relief after 3 years since starting this project.
Was it worth all the effort?
3 years is a long time to build a model aircraft. CNC foam cutting isn’t a long process but I lost a little motivation and got sidetracked on to other builds. Also, my second grandchild arrived during the build.
Yes, it was worth it because it looks great and flies really well and I went on to build another model like this my T45 Goshawk but that’s another story!