Balsa EDF jet build!

[L Edge]

Suggestion:
Start off with just using elevators in canards and then work your way up to to the ailerons. Since you have a delta wing, rolls are going to be fast and it takes awhile to learn how to the extra controls. Suggest you start with 30% travel of elevator travel and work your way up. You don't want to crash that nice looking bird. I have a F-22, Delta Storm, and the FT Viggen that all have a second set of elevons.

I hope your CG works out for you.

 

[ThomasMartino]

Suggestion:
Start off with just using elevators in canards and then work your way up to to the ailerons. Since you have a delta wing, rolls are going to be fast and it takes awhile to learn how to the extra controls. Suggest you start with 30% travel of elevator travel and work your way up. You don't want to crash that nice looking bird. I have a F-22, Delta Storm, and the FT Viggen that all have a second set of elevons.

I hope your CG works out for you.

Thanks for the advice. I’ll ease into the aileron mixes once I see what the roll rate is like. I do a lot of 3D flying, but I have never flown a jet in real life so I’m not used to that kind of speed and energy

 

[L Edge]

Thanks for the advice. I’ll ease into the aileron mixes once I see what the roll rate is like. I do a lot of 3D flying, but I have never flown a jet in real life so I’m not used to that kind of speed and energy

If you can do 3d, once you get use to movable canards, you can do the high alfa stuff on launch as well as if you get engine out while flying, nose down at a good speed and use the canards to flare and save destruction.

 

[ThomasMartino]

Canards are covered and installed! I’m very happy with how they turned out. Most of the plane will be matte gray, but I will be adding some orange accents with tiger stripes for a tiger meet style scheme.

I’m nearly done sheeting the top of the plane. The fuselage is entirely compound curves, so it will take a lot of careful sanding to make everything flow, but it will be worth it in the end.

Now for the bad news... my original weight estimates were way off (aren’t they always?). The current weight with batteries is 2.5 pounds. I still have to finish the fuselage and install the bottom wing skins, then fiberglass the entire airframe and paint it. I will try to keep everything as light as possible, but it will probably be 3-3.25 pounds ready to fly. I’m only using a 64mm EDF but it’s rated for 800 watts so I think my power loading will be okay. If it ends up being 3.25 pounds the wing loading would be 23oz/sqft which is high but not unreasonable

 

[Flitedesign 3d]

Canards look very good. Which edf are you going to use? Better be dynamically balanced with that kind of power

 

[Grifflyer]

Great work so far!! Can't to see this in the air!!

 

[ThomasMartino]

Canards look very good. Which edf are you going to use? Better be dynamically balanced with that kind of power

Thanks! It’s a Hobbyking unit that I bought used. The website says they are dynamically balanced and so far it has run smoothly. If the EDF gets damaged in any way it would be impossible to remove it without seriously hacking up the underside of the fuselage, so hopefully I won’t have any issues...

 

[ThomasMartino]

Great work so far!! Can't to see this in the air!!

Thank you! I’m really excited to finish it up and fly

 

[Grifflyer]

Thanks! It’s a Hobbyking unit that I bought used. The website says they are dynamically balanced and so far it has run smoothly. If the EDF gets damaged in any way it would be impossible to remove it without seriously hacking up the underside of the fuselage, so hopefully I won’t have any issues...

EDFs are pretty well protected, as long as you do don't suck any rocks or pebbles into the inlets you shouldn't have to worry about it getting damaged.

 

[Flitedesign 3d]

EDFs are pretty well protected, as long as you do don't suck any rocks or pebbles into the inlets you shouldn't have to worry about it getting damaged.

Yea destroying your edf by sucking in your receiver really sucks, don't ask me how I know.

 

[Grifflyer]

Yea destroying your edf by sucking in your receiver really sucks, don't ask me how I know.

Hahaha I remember that

 

[ThomasMartino]

I finally got to work on the jet again! I made the elevons, continued skinning the plane, and began applying fiberglass.

I’m getting seriously concerned about weight. It’s three pounds with batteries and I still have to glass the bottom. I used 2.75oz/yd S glass for the top of the wings and that contributed significantly to the sudden weight gain. I’ll used 1.4oz/yd E glass for the bottom.

I fear the finish quality is going to suffer for the sake of keeping weight down. I won’t be able to fill the weave with multiple coats of primer, so I’ll just spray it once, wet sand, then spray a final coat of matte gray.

 

[ThomasMartino]

I finished closing everything up and glassed the bottom of the plane. Note the 12K carbon fiber tow used to reinforce the leading edge of the wing and the bottom of the fuselage. I’ve built this plane unnecessarily strong and that cost me dearly in weight, but at least it will hold up well if it gets banged around. It’s looking like the flying weight will be 3.5lb. The advertised max thrust of the EDF is 2.33lb. It should fly but the power loading will be high.
I’m going to refrain from adding body filler in an effort to keep the weight down. I’ll spray heavy coats of primer and then wet sand them until I’ve knocked down all the high spots. Once that’s done I’ll spray a light coat of matte gray and add some stickers

 

[ThomasMartino]

Here it is after the first coat of primer. I’ll let it cure overnight then start sanding. Overall I love how it looks and I’ve really enjoyed building something completely different than my past projects.

 

[ThomasMartino]

After about two hours of wet sanding using 60, 80, 100, 120, 150, and 180 grit I decided it was as good as it was going to get. I sprayed it with another coat of primer and this is how it will stay until the maiden flight. I changed the canopy position so now it doesn’t fit quite right, but if it flies well I can build a new canopy that looks better.

 

[NickRehm]

Awesome build! I might suggest throwing together a simple profile foamie copy of this to fly around to figure out cg/flying characteristics before unleashing the real thing

 

[ThomasMartino]

Awesome build! I might suggest throwing together a simple profile foamie copy of this to fly around to figure out cg/flying characteristics before unleashing the real thing

Thanks! I should probably do that. This plane is wildly underpowered so if my CG is off I doubt I will be able to recover from a bad situation

 

[NickRehm]

Yea, you could even add weights so its comparable to the composite version to test out... wouldn't want to endanger that beautiful airframe

 

[ThomasMartino]

It flies! The first flight was very short because the ESC burned up and I had to make a deadstick landing, but the plane handled well and I landed it safely.

 

[ThomasMartino]

The ESC failure was due to over current. The plane didn’t have enough power on 4s so I switched to 5s batteries and forgot to check the amp draw. The 50 amp ESC never stood a chance. I replace it with a 100 amp unit and now everything works great. Both ESCs are optos, so I use a separate battery and BEC for the receiver and servos.