Hot Foam cutter for RC aircraft

**markc** · 17-10-2010

Hi Keith, how is your hot wire cnc progressing? Just joined to learn more about cnc routing and hopefully build one in the future but have already built a foam cutter from the same plans you are using. I used hobbycnc foampro board and stepper kit and running it with GMFC, it is a simple machine, works reasonably well but quite slow compared to more complicated but smoother running builds, cuts great cores that are so much better that anything possible with a drop arm set up and no more template cutting which for me is the best bit of all. I would recommend using a bow for the hot wire though, the spring set up in the plans puts tension on the towers and the drawer sliders need all the help they can get. Like your website by the way, you may find mine interesting also http://valegliders.com

Mark

**rckeith** · 17-10-2010

Hi mark

Foam cutter is on hold for a few months. I have all the parts and just need some time. I'm concentrating on my VC10 build which is a 2 year project that I'm coming close to finishing. The VC10 was the inspiration for a cnc foam cutter, so many templates. I hope to use the cnc foam cutter for fuselages as well. I'm aiming to make a Lancaster with it. I already have a Priory Models Lancaster, in a a bit of mess after a crash but I would like to be able build one a lot lighter. Thanks for king comments on the website, your looks slick as well. I'm hoping to start back on the foam cutter after Christmas this year. Good advice on the bow, I wondered if the spring on the wire would cause some issues with the towers.

Keith

Keith

**rckeith** · 06-07-2012

Been a while since I've posted here but due to other RC projects foam cutter had to take a back seat. Well I'm glad to say I've finished building and it works!! Just jogging the motors at the moment with Mach3 but all seems good. Calibrated the motors today now I need to get some 4 axis gcode generated. Posted some new pics on my website http://www.rckeith.co.uk/cncfc.html scroll to the bottom. Next bit is deciding which software to use to generate the gcode. Currently playing with a demo version of FoamWorks with a 30 day license.

Keith

**bobc** · 06-07-2012

Looks like a nice project. My 3D printer uses M8 threaded rod, it works surprisingly well considering the price. I have always had doubts about the accuracy, but when printing at a resolution of around 0.1 mm it is not critical. The bigger problem I have is "wobble", although I think that is more of a design issue with the printer frame.

Unfortunately, the price hike to leadscrew is pretty steep. I priced up 4 sets of 10mm leadscrew and it was way too much. I would be better putting it towards a new machine.

A couple of questions: how is the wire tensioned? Presumably it has some stretch to allow for change in distance while it is cutting a profile?

Is there anything special in the software setup to handle the fact you effectively have two X,Y coordinates? My understanding of the GCode machine model is that all axes in a G1 move are synchronised and coordinated, so it does not matter how or where the axes are.

**rckeith** · 06-07-2012

Hi Bobc

Wire will be tensioned by spring to allow for the x axis on both towers to move interdependently for cutting tapered wings. I'm testing out different software but profili2 pro has 4 axis for foam cutters and foamworks generates the gcode as well.

post some more pics up soon when I have it cutting some foam

Keith