$2 KFm4 Scratchbuilt Wing Build Plans

Flight Video

Airframe Overview

This is a 30" scratchbuilt flying wing made from only 2 sheets of dollar tree foamboard suitable for combat, FPV, and fun flying.

I covered mine with packing tape to help protect the foam from rough landings in gravel here in the Arizona desert. A couple strips of duct tape reinforce the center where all the electronics are mounted.

I'm using a 2200kv Turnigy D2826-6 motor with a 6x4 APC or Master Airscrew prop with a 2200 mAh 3S. This setup gives me great vertical, yet still preserves a great glide ratio. My servos are HXT-900 9gram.

With an aluminum motor mount, add a little down thrust to keep the plane flying level.

The CG balances well to start at the KFm step in the center of the aircraft. Gradually move the CG back to gain better maneuverability up to 1" back.

I have provided downloadable PDF plans, but I think it is easier to just reference dimensions off these next couple photos instead of printing out the plans.

The vertical stabalizer dimensions are not critical. Make them as big as you like.

Bevel the long edge of the elevons, and then attach using packing tape or hot glue.

 Score the paper at the dotted lines to remove a strip of paper. this allows you to bend these pieces over the leading edge of the main wing piece. Secure everything with hotglue.

The airframe flies perfect without any reinforcement. However, if you would like the plane to last forever, add a strip of extreme packing tape along the bottom of the wing to prevent the wing from gradually folding in high-g maneuvers and crashes. I have at least 100 flights on mine, all of which have rough landed in gravel (grass fields are rare and boring), or crash landed into cacti or tree. It still flies perfect, although it definitely shows some battle scars and puncture wounds.

Sheet 1 Plans

Sheet 2 Plans