Kangke offers two versions of their "F3D" ARF. One is for electrics and one is for gas. Same plane though. The gas version has a firewall installed and possibly some type of motor mount. From what I've heard, you can get a Nelson in it with lots of dremel-tooling. The electric version has no firewall - thise is the version I purchased. I simply had to make a 1/4" firewall and glue it in. I then reinforced it with fiberglass and resin. The fiberglass fuselage is not epoxy, but instead it is polyester resin - similar to some of the old pattern kits. Polyester resin is cheaper than epoxy and is easily found at hobby shops (K&B makes some) or at Home Depot / Lowe's.

The 2nd modification consists of simply running a 1" wide fiberglass tape along the inside seam of the fuselage. Evidently Kangke did not add glass when they glue the two fuselage halves together. Probably not an issue if you plane to fly it with an OS 25. Samething here - you have to use polyester resin. I used a acid brush squeezed on a dowel to lay the glass tape down inside the fuse back near the horizontal tail.

The 3rd and final mod that I did was to throw away the landing gear and wheels that were included in the kit and put on some standard Q500 L-1 aluminum gear with pizza cutter type wheels.

I've made two so far using these modifications and the planes fly great. I did not discover these modifications on my own - Don Stegall told me about them. This cheap but fast kit got me going in Q40 without a doubt.