EDF FT Flyer

Quick Intro:

I tried to keep the video self explanatory. Basically I built this because I bought an EDF and I wanted to start playing around and experimenting with it. I wanted to start with an existing airframe. I have also been wanting to build the FT Flyer for a while. I admit that this wasn't the best airframe to convert into an EDF. But I liked how easy to build it was. The plane is too inefficient to ever pick up speed. EDFs are known to take a while to pick up speed, but with the FT Flyer, it almost can't. This is actually a great beater plane because of it's durability, but it can be difficult to fly.

Video:

Pros and cons:

Because the EDF is two inches back into the fuselage, it is nearly impossible to damage it. Which means no broken propellers. I have nose dived plenty of times and I didn't have to make a single repair (except the velcro that holds on the battery kept coming off but that doesn't count). Not only does that make flying more enjoyable, it also makes it cheaper. Because this is the FT Flyer, it is easy to fly. A simple three channel plane. And it is easy to build.

Some of the down sides are that I have to hand launch it with a fast hand to get it started at the correct speed. If I had landing gear on it, it would either take a very long runway to get it going, or it might not get off the ground at all. Because it has such a difficult time gaining speed, if I lose too much and get it too close to the ground, I have no way to pull up, I have to land it. Sometimes I landed it with full throttle and didn't break anything, but that's a good thing. Long story short, this can be rather difficult to fly because it is under powered and the only way to fix that issue is to use a propeller instead of EDF.

Another downside is that I have to externally mount the electronics. Not only is it uglier as a result, but it also leaves the electronics open to damage.

In conclusion, this is a great beater plane. I can just take it out, have fun, and no need to worry about breaking it. It can be frustrating at times to get it going and to gain altitude. Which is why I'm weary about saying that this would be a great first plane. I will say that it's probably the cheapest way to get into the hobby. I did fly it with the $30 Tx from Hobby King. It's not really a bad thing that it has to be flown at full throttle, that just means one less control to worry about when flying. But if you decided to try this for yourself, just know that it is underpowered and the inability to gain altitude might not be your pilot skills. Maybe it would be good to start out with this plane, but then quickly build the original version once you're more comfortable with your ability.

Electronics used (and recommended):

EDF: http://www.hobbyking.com/hobbyking/store/__22947__Hobbyking_50mm_Alloy_EDF_4800kv_3s_Version_.html

ESC: http://www.hobbyking.com/hobbyking/store/__6458__Hobbyking_SS_Series_25_30A_ESC_card_programmable_.html

Battery that I used: http://www.hobbyking.com/hobbyking/store/__18203__Turnigy_nano_tech_850mAh_3S_45_90C_Lipo_Pack.html

Recommended battery (because of weight/under powered issue): http://www.hobbyking.com/hobbyking/store/__33192__ZIPPY_Compact_500mAh_3S_35C_Lipo_Pack_USA_Warehouse_.html

*note: I recommended a battery from the USA warehouse at Hobby King because it's a bad idea to order batteries from the International warehouse. It'll slow down your order because the order might sit in customs for a while because of the LiPo batteries. (It's hard to get LiPos onto commercial planes.)

Photos of plane (taken before maiden):

Build pictures and some tips:

Here is the EDF that I used. I know it says "Dr. Mad Thrust" on it, but this is the one that I have a link to. Hobby King is weird and will update the product without updating the website. (The Dr. Mad Thrust brand has a 10 blade fan, this one has a 5 blade fan, just like the "Hobby King" brand that it's listed as on the website.)

The measurements I have written on the foam board is correct. The spaces between are 1/4". I did end up making the fuselage a little too big around the EDF, but it's close enough. If you decide to build a similar plane, either use my measurements (if using a 50mm EDF) or see if you can do better. I have the EDF about 2inches back. This left the weight forward enough to get proper CG, but has the EDF far back enough to avoid getting damaged.

I cut score lines into the fuselage so the lip of the EDF can bite into the foam to help hold it in place.

I did not glue the EDF in place because I didn't want to have to unglue it. Instead I used two bamboo skewers to stop the EDF from moving forward. I probably lost efficiency from doing this. Plus the motor eventually got looser and has a slight thrust angle. It's not noticeable because of the long tube the exhaust goes through, but again I'm probably losing efficiency.

After I had the fuselage done, I glued it directly to the wings. I don't have pictures of this because it's not different than the original FT Flyer. Except that I didn't use any tabs to hold it in place. I was going to glue it anyway and creating the tabs and then figuring out where to cut the slots into the wings seemed like a waste of time.

Other than modifying the fuselage to hold the EDF, I also had to modify the rudder. Those really are the only two modifications needed. I cut out the rudder according to the plans (probably a waste of foam board) and then held it in place with the elevator under the fuselage. Then I measured the gap so I knew how far to extend the rudder. It ended up being about two inches.

Here it is, almost done, but then I noticed a mistake.

I put the control horn on according to the original FT Flyer plans. Which doesn't work with my modified/bigger fuselage. Instead of redoing it, I decided to just put the servo right there. Of course this affect the CG and I had to have my battery all the way at the nose as a result.

I guess those are all of my pictures. I had to mount all of the electronics externally because I didn't want them in the way of the airflow of the EDF. I also want to quickly mention that the reason why I left the elevator on the bottom was so that the exhaust from the EDF will blow right onto the control surface when I pull up. Meaning that having throttle will help push down the tail, raising the nose. I also left the rudder in the way of the exhaust for the same reason. I'll have more control as a result. Although, I may be losing efficiency which might be part of my under powered problem.

The flying weight of this plane was originally 380grams which proved to be too heavy. It is flyable at that weight, but barely and it doesn't take much to lose the speed needed to keep it flying. That was with a 1300mah 3cell battery. With my 850mah 3cell I was able to bring the weight down to 340grams. But that was after I removed some foam board. I regret doing that because it looks bad and I didn't really lose any weight. I doubt the removed foam did anything aerodynamically.

Conclusion:

I don't really want to say that this is a great way to start off this hobby, but it is probably the cheapest. The EDF is $20. Yes a good motor is only $10 and another $10 can buy quite a few propellers. But lets be honest, a newbie is going to go through those $10 of props in no time. Plus it can get frustrating to keep repairing the aircraft. This can, hopefully, just be picked up and tossed again. Just be sure to toss it with some speed.