Mark's RC Powers Foam Extra 300

I enjoy watching RC Powers videos on YouTube. Although they don't work much with balsa, they do love to experiment. I suppose that is why they use foam. Anyway, they have a number to inexpensive or free plans for foam planes on their web site.

Basically you download a PDF file and print it out. You then tape the pages together and cut out patterns that can be traced onto foam. Following is a picture of me transferring a pattern onto a sheet of foam.

Next you cut out the foam pieces and then hot glue them together.

This is my finished product. I have not flown it but it looks like fun. I have enough foam to make at least three models so I'm sure I will make more.

After completing the build and taking the above photo, I decided to add landing gear so I could fly out of parking lots as opposed to just grass fields. I also spend some time trying different battery and prop combinations to see what worked best with the motor I had installed. I settled on a 2-cell with a 9 x 4.5 prop although I think a prop with just a bit less pitch might be a little better.

Originally I had designed my motor mount as a breakaway design built with dowels and rubber bands. You and kind of see it in the above photo. However, after selecting my prop I decided to see how well it would work with a 3-cell battery. I powered it up too quickly and proceeded to twist the motor off the front of the plane. The next photo shows the motor securely mounted to the ply firewall. Notice the nose is about an inch shorter in that photo.

The following picture was taken after my second day of flying. Its first flight was in five to ten miles per hour wind and surprising it flew quite well. Unfortunately, as I was making a turn away from the wind I lost it in the morning sun and flew it straight into the ground at full speed. That crash broke the left wing and the motor fell off. I hot glued it and installed some packing tape over the repair for additional strength and took it out the next day.

I was surprised how well my hot glue repairs held up. I don't think I needed the additional packing tape. My second flight was made in winds under 5mph on an overcast morning. No chance of losing the plane in the sun this time. The first thing I noticed was the plane required up elevator trim - maybe 6 degrees or so. I have my motor mounted with a little down and right thrust so maybe mounting it level (with a little right thrust) would be best. I then added just a little aileron trim and it was a straight flying plane.

The first thing I tried was a vertical hover. It was easier than I thought to get it into the hover but as I expected it was hard to hold it there. Although I could not hover for more than a few seconds it was not as hard as I thought it would be. It was also easy to recover without losing a lot of altitude when it did go out of control. I then tried roles and inverted flight along with some other maneuvers. It was fun to see how quickly the plane turned. I lost it once while maneuvering close to the ground but only broke off the tip of one of the wings.

I noticed I no longer had enough battery to attempt vertical flight so I decided to come in and replace the battery. As I setup for final I had planned on gliding down the last five feet as I usually do. However, as soon as I cut power the plane lost most of its lift and dropped to the ground. Full up elevator made no change. Luckily nothing was broken.

I replaced the battery and was surprised how much fun it was to fly with the added power. Both batteries are two cells which makes me wonder how much fun it would be with a three cell. Anyway, I tried more vertical hovers, quick aileron roles, sap roles and amazingly quick loops - all at about 25 feet up which seemed plenty high considering how responsive the plane is. I then decided to do an outside loop to inverted flight from that same altitude. Instead of quickly flipping over the plane entered a large loop and at the same time the elevator developed a lot of flutter. As the flutter increased the outside loop decreased and the plane flew into the ground upside down. This broke the motor off and cracked the right wing.

I will hot glue it back together and hopefully fly it again next weekend. I will probably trash it after the next crash and build another.

I was hoping I could fly this in a small parking lot but I can see it will take some practice before I'm good enough to fly it in a small area. I'm using about a quarter of a football field now. While trimming it I needed close to half of a football field. I would guess with a little practice this could easily be flown in front of my house.

I have been having fun flying this plane. I added KF airfoils to straighten the wins after snapping one off in a crash. It flies much more like a real plane with the KF airfoils. I snap off the motor on about half of my landings. The foam breaks just behind my motor mount. I have tried adding epoxy, additional foam, and a breakaway motor mount without any luck. I'm using my oldest outrunner motor which is fairly heavy; I think a lighter motor would be less apt to break off on landing. Aside from that one problem, I'm really enjoying this plane. Currently I would say it is my favorite to fly as far as having an enjoyable flight.

I finally decided to rebuild the Extra 300 after many repairs. I made a few miner changes with the new Extra but aside from the color it is basically the same.