YC-14 Build (From MikeysRC)
- Thread starter dezertdog
- Start date
dezertdog
Senior Member
Haha, well it was late and I was feeling creative. The big issue I had was that the servo arms I have aren't long enough, so I wasn't getting enough travel. This little contraption solves two issues, the single servo part, and it has mechanical advantage giving me more throw.
Also wrapped up the rudder control over breakfast. I learned in the Mark I build to not "permanently" install servos in foam! I just dug out a snug square hole, wrapped the servo with tape, taped off the surface and used a surface bead of hot glue. It's strong enough to stay put, but super simple to "pop" out if needed. Glue clean up is as simple as removing the tape.
Also wrapped up the rudder control over breakfast. I learned in the Mark I build to not "permanently" install servos in foam! I just dug out a snug square hole, wrapped the servo with tape, taped off the surface and used a surface bead of hot glue. It's strong enough to stay put, but super simple to "pop" out if needed. Glue clean up is as simple as removing the tape.
dezertdog
Senior Member
I've been saving the last step piece so I can hide all the wiring for the motors. Notched out a little trough, and dabbed the wires down with hot glue.
Left some squares on the leading edges for firewalls.
Cut up a couple from some old hollow pantry door skins (which I covered in extreme packing tape to help against cracking).
And there we go, a plane! I guess technically is would fly right now, all the "things" work, but it's not as aerodynamic as it could be. It's got a date with the power sander tomorrow outside in the daylight to smooth things out, and then...we maiden!?
Ended up being about 20% heavier than Mark I. I took it out in the yard with a battery and GoPro taped in the nose and did some "run, toss, catch" drills and it seems to behave well. The one time I let it go, it did stall earlier than Mark I, but I guess I expected that.
I used some online CG and stall calculators to crunch some numbers and the CG seems to want to be (give or take 5%-10% Static Margin) about 3"-3.5" from the LE. The tests with the battery and GoPro taped up front make me think that's easy enough to accomplish.
This is super familiar, that feeling of accomplishment, but unease. On paper Mark I should have been great, but it was super fragile and the flight characteristics were off due to bad CG and thrust angles. I "addressed" those in Mark II, but who knows? Oh wait, I will Probably tomorrow.
Left some squares on the leading edges for firewalls.
Cut up a couple from some old hollow pantry door skins (which I covered in extreme packing tape to help against cracking).
And there we go, a plane! I guess technically is would fly right now, all the "things" work, but it's not as aerodynamic as it could be. It's got a date with the power sander tomorrow outside in the daylight to smooth things out, and then...we maiden!?
Ended up being about 20% heavier than Mark I. I took it out in the yard with a battery and GoPro taped in the nose and did some "run, toss, catch" drills and it seems to behave well. The one time I let it go, it did stall earlier than Mark I, but I guess I expected that.
I used some online CG and stall calculators to crunch some numbers and the CG seems to want to be (give or take 5%-10% Static Margin) about 3"-3.5" from the LE. The tests with the battery and GoPro taped up front make me think that's easy enough to accomplish.
This is super familiar, that feeling of accomplishment, but unease. On paper Mark I should have been great, but it was super fragile and the flight characteristics were off due to bad CG and thrust angles. I "addressed" those in Mark II, but who knows? Oh wait, I will Probably tomorrow.
Last edited:
dezertdog
Senior Member
dezertdog
Senior Member
Lol drive you nuts a bit? Don't worry not 100% yet.
Oh yeah, I can't stand seeing them!
dezertdog
Senior Member
Maiden success! I was able to get about 6 minutes airtime in today before the after work dog walking crowd started to take over my "airfield" and I had to call it.
Here is a quick vid from the "head cam" of it's first takeoffs, passes and landings.
So first reactions.
- It flies! WOOOOOOOT! :applause:
- CG is still tail heavy, but MUCH better than before.
- Tail heavy planes want to roll!
- Thrust angles seems great.
- KFm3 has great handling and stall characteristics.
- Flies like well at 1/2 throttle, but not much "emergency" power.
- Replacing 2650 mAh 2S battery with a 3300mAh 3S to gain more prop rpm and nose weight.
- Elevators could be more responsive, making them 100% longer.
- Rudder gives great coordination, but won't crab in forward flight. Extending 100% too.
- Ailerons are super responsive, 25% expo seems about right.
- Differential is working great, coordinated turns gives no skidding.
- You can "hear" the difference from the props in turns with rudder vs no rudder.
- Flaps at 4* makes things nice and tight. Needs more experimentation after tail changes.
- 1" foam is about indestructible.
- Hand launching a 50" wingpsan is not super easy.
- Full throttle before letting go, and throw it UP!
- Did I mention it flies!?
- This thing is begging for some FPV flight.
Here is a quick vid from the "head cam" of it's first takeoffs, passes and landings.
So first reactions.
- It flies! WOOOOOOOT! :applause:
- CG is still tail heavy, but MUCH better than before.
- Tail heavy planes want to roll!
- Thrust angles seems great.
- KFm3 has great handling and stall characteristics.
- Flies like well at 1/2 throttle, but not much "emergency" power.
- Replacing 2650 mAh 2S battery with a 3300mAh 3S to gain more prop rpm and nose weight.
- Elevators could be more responsive, making them 100% longer.
- Rudder gives great coordination, but won't crab in forward flight. Extending 100% too.
- Ailerons are super responsive, 25% expo seems about right.
- Differential is working great, coordinated turns gives no skidding.
- You can "hear" the difference from the props in turns with rudder vs no rudder.
- Flaps at 4* makes things nice and tight. Needs more experimentation after tail changes.
- 1" foam is about indestructible.
- Hand launching a 50" wingpsan is not super easy.
- Full throttle before letting go, and throw it UP!
- Did I mention it flies!?
- This thing is begging for some FPV flight.
Last edited:
Revj Vegas
Member
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Maiden success! I was able to get about 6 minutes airtime in today before the after work dog walking crowd started to take over my "airfield" and I had to call it.
Here is a quick vid from the "head cam" of it's first takeoffs, passes and landings.
So first reactions.
- It flies! WOOOOOOOT! :applause:
- CG is still tail heavy, but MUCH better than before.
- Tail heavy planes want to roll!
- Thrust angles seems great.
- KFm3 has great handling and stall characteristics.
- Flies like well at 1/2 throttle, but not much "emergency" power.
- Replacing 2650 mAh 2S battery with a 3300mAh 3S to gain more prop rpm and nose weight.
- Elevators could be more responsive, making them 100% longer.
- Rudder gives great coordination, but won't crab in forward flight. Extending 100% too.
- Ailerons are super responsive, 25% expo seems about right.
- Differential is working great, coordinated turns gives no skidding.
- You can "hear" the difference from the props in turns with rudder vs no rudder.
- Flaps at 4* makes things nice and tight. Needs more experimentation after tail changes.
- 1" foam is about indestructible.
- Hand launching a 50" wingpsan is not super easy.
- Full throttle before letting go, and throw it UP!
- Did I mention it flies!?
- This thing is begging for some FPV flight.
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dezertdog
Senior Member
Ok now the rudder is way more proportional. Since there is no T tail I extended the rudder up into that space as far as I could. With the height and length gain it's also about a 100% increase. The elevators and rudder were rebuilt with 1/2" thick foam to try and come out at least even on tail weight.
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dezertdog
Senior Member
Just got back from about 10 minutes of airtime with the new rear controls, much better!
I had the GoPro up front, and now it's actually a little nose heavy which is great, very fixable. The elevator still isn't anything amazing though, I mean it climbs just fine, but I'd like to be able to hit dual rates and really push it. I think I'll have to look into maybe some longer servo arms, or maybe think about going direct linkage to dual servos. Anyway, it's totally to the point where I can charge up, hit the airfield and fly without any worries. A-w-e-s-o-m-e.
Mixing up a vid of the fpv stuff now.
I had the GoPro up front, and now it's actually a little nose heavy which is great, very fixable. The elevator still isn't anything amazing though, I mean it climbs just fine, but I'd like to be able to hit dual rates and really push it. I think I'll have to look into maybe some longer servo arms, or maybe think about going direct linkage to dual servos. Anyway, it's totally to the point where I can charge up, hit the airfield and fly without any worries. A-w-e-s-o-m-e.
Mixing up a vid of the fpv stuff now.
