Hot Wire CNC flying wing build details

Here are the build details and videos of my first hot wire flying wing made with my CNC foam cutter. If you’d like to build a foam cutter I have all the information here https://rckeith.co.uk/cnc-hot-wire-foam-cutter/.

Here’s the finished YMF-38. She flies extremely well and can eat up the sky

hot wire cnc flying wing — The YMF-38 flying wing

Details and Dimensions

I’ve called it the YMF-38 as it has 38″/960mm wingspan. It uses MH-45 airfoil sections and a 2200KV brushless motor with a 6×4 prop. A 2200mAH Lipo gives about 8-10 minutes of flying. It flies well and is quite fast. I used XPS foam with 9-gram servos. I’ve had a few servo failures using the cheap 9 grams so now I use the metal-geared MG90S which are sometimes as cheaper than plastic-geared servos.

I’ve built a few now with white Styrofoam as well, a bit cheaper and if you follow my covering process https://rckeith.co.uk/cover-wings-fuselages-brown-paper-white-glue/, very strong.

G-code generation

The wing was designed in Profili Pro 2 which creates the g-code I then load into Mach 3. Since building this wing I’ve upgraded to DevWing Foam2 and use my Grbl Hotwire software with a 32-bit USB controller.

If you need Free options to make the wing article https://rckeith.co.uk/foam-wing-free-cnc-software/ here has details.

Here are the dimensions. The centre of Gravity is 6.25″/158mm from the nose. The endplates are 6mm depron which you can use any design you like.

Here’s the setting from Profili2 Pro. This software has now been replaced by DevWing Foam which I have upgraded to and will update the page and have a video tutorial

Once you’ve cut the wing trim the root and tip to the correct angles. Check my video https://youtu.be/_UFOHJPlza8 it explains the process and will save wasting a lot of foam.

Here’s the placement of the 3mm carbon rods. I used a Dremel with tile attachment to cut a slot and filled it with lightweight filler.

I then covered it in iron-on Solar film. The battery is secured with velcro and a strap that goes through the wing. The launch is easy, on the underside there is a small grip which you can hold and apply about 3/4 throttle and she leaps away. See the second video below the video’s below

Stupid Boy

I crashed it. I’d forgotten to check my transmitter rates switches and the elevator was on a low rate setting. After the launch, I thought this didn’t feel right I better land. But before I could it just wouldn’t pull up and I ended up in a field of oilseed rape (canola) crop surrounding the flying field. I did triy to find it but this type of crop is difficult to get through when it’s almost ready for harvest, so I had to leave it. Damn.

Well after about 2 weeks the crop was cut and one of the other club members spotted it on his way home. Everything still worked apart from one servo but I did not trust the receiver as the air-frame felt wet. So it’s time to make another.

New Hot Wire CNC Flying Wing

This is the rebuilt wing I’ve used white foam and 3 carbon rods and then it’s been covered in brown paper and solar film. Weight was 405 grams without battery and with a 3S 2200 mAh 608 grams. The videos below show the search, recovery rebuild and Maiden flight.