50% Old Fogey Park Flyer Trainer

[iflighthub]

I decide to make 50% scale of Old Fogey as my trainer because i thing full scale FT Old Fogey may quite too big for the area i supposed to fly on..


Wingspan : 510mm
Full length : 420mm
Motor : emax CF2812
Prop : 7x4SF
Lipo : 850mah 3s

 

[mymaps]

Wow I'm very interested, I also though on building something smaller, an FT Flyer initially, and see how it does it, but I have been hesitating on which electronics I should use.

Did you maiden it? How does it fly at really low speeds?

 

[Biff45452]

Very nice, isn't that motor a little big though. I looked it up and it's rated for 600+ grams of thrust! Thats gotta be a thrust-to-weight ratio of like 10.

 

[iflighthub]

Very nice, isn't that motor a little big though. I looked it up and it's rated for 600+ grams of thrust! Thats gotta be a thrust-to-weight ratio of like 10.

After i weigh the plane, it was around 350g. I checked the motor specs and it said 200-600g grams. Is it too heavy motor? Thanks

 

[nerdnic]

Try to shed weight, my 50% old fogey was 160g.

 

[JohnRambozo]

His weight is probably motor and battery. 50% Fogey is a cool idea.

 

[nerdnic]

Yeah it definitely is his battery. Mine was AUW 160g, something that heavy might not fly very well. The old fogey has a sweet spot for speed and weight that you gotta hit for it to perform well.

 

[iflighthub]

Wow I'm very interested, I also though on building something smaller, an FT Flyer initially, and see how it does it, but I have been hesitating on which electronics I should use.

Did you maiden it? How does it fly at really low speeds?

not yet. maybe this weekend.

 

[iflighthub]

Yeah it definitely is his battery. Mine was AUW 160g, something that heavy might not fly very well. The old fogey has a sweet spot for speed and weight that you gotta hit for it to perform well.

how much is the weight of the full size FT Old Fogey. I guess around 400~500g but i'm not sure. i will try to change my battery to reduce the weight.

 

[iflighthub]

His weight is probably motor and battery. 50% Fogey is a cool idea.

do you think this is too heavy. I done the basic math.

CF2812 7x4 prop using 3S.
as per manufacturer 7x4 prop will produce 10.5A, so for 3s (10.5A x 11.1v=116.5watts).

current weight including motor and 3s battery is roughly 320g or 0.70lb.

for Trainer and Slow flyer, 70~90 watts/lb.

so... 70watts/lb divide by 116.5watts = 0.60lb for 90watts/lb it will be 0.77lb.

so therefore my 320g (0.70lb) 50% Old Fogey will fly smoothly.

please correct if my calculation is wrong. thanks for the guide!

 

[iflighthub]

Yeah it definitely is his battery. Mine was AUW 160g, something that heavy might not fly very well. The old fogey has a sweet spot for speed and weight that you gotta hit for it to perform well.

do you think this is too heavy. I done the basic math.

CF2812 7x4 prop using 3S.
as per manufacturer 7x4 prop will produce 10.5A, so for 3s (10.5A x 11.1v=116.5watts).

current weight including motor and 3s battery is roughly 320g or 0.70lb.

for Trainer and Slow flyer, 70~90 watts/lb.

so... 70watts/lb divide by 116.5watts = 0.60lb for 90watts/lb it will be 0.77lb.

so therefore my 320g (0.70lb) 50% Old Fogey will fly smoothly.

please correct if my calculation is wrong. thanks for the guide!

 

[iflighthub]

Very nice, isn't that motor a little big though. I looked it up and it's rated for 600+ grams of thrust! Thats gotta be a thrust-to-weight ratio of like 10.

do you think this is too big. I done the basic math.

CF2812 7x4 prop using 3S.
as per manufacturer 7x4 prop will produce 10.5A, so for 3s (10.5A x 11.1v=116.5watts).

current weight including motor and 3s battery is roughly 320g or 0.70lb.

for Trainer and Slow flyer, 70~90 watts/lb.

so... 70watts/lb divide by 116.5watts = 0.60lb for 90watts/lb it will be 0.77lb.

so therefore my 320g (0.70lb) 50% Old Fogey will fly smoothly.

please correct if my calculation is wrong. thanks for the guide!

 

[Biff45452]

Hopefully it will fly, there is only one way to find out. The store page for the full size Old Fogey says it is 377g and the recommended battery weighs 79g for a total of 456g. So I would think you should be no more than half that. If you look at similar sized planes like the hobbyzone champ they all use micro power systems with 1s batteries.

 

[Crash_Expert]

How does it fly?

Is it small enough for a front yard?

C_E

 

[OrangutangSurfer]

I built an 80% FT flyer, I put the same 24g motor and ESC as recommended for the full size and the good ol' 9g servos. I was worried about it being to heavy. I used a 2s 850mah battery and it flew AWESOME! Even did well in 10+mph winds.

I know the old fogey wouldn't fly in that much wind but I like the 80% or less size planes they are easier to transport and fly well on the same power packages. Before I scale any smaller I'm waiting for the supposed ultra micro FT planes coming this fall! Until then I think I"ll give the 80% Fogey a try and transfer my Flyer Power pod over and see how it does. my 80% Spitfire is a blast as well (thanks nerdnic for the awesome idea!)

I'm tempted to make a 50% fogey but I would probably go with a super light power setup.

-Jes

 

[nerdnic]

do you think this is too heavy. I done the basic math.

CF2812 7x4 prop using 3S.
as per manufacturer 7x4 prop will produce 10.5A, so for 3s (10.5A x 11.1v=116.5watts).

current weight including motor and 3s battery is roughly 320g or 0.70lb.

for Trainer and Slow flyer, 70~90 watts/lb.

so... 70watts/lb divide by 116.5watts = 0.60lb for 90watts/lb it will be 0.77lb.

so therefore my 320g (0.70lb) 50% Old Fogey will fly smoothly.

please correct if my calculation is wrong. thanks for the guide!

So the issue isn't will it fly, it's will it fly well. I can't fully answer that but my thought is probably not. The old fogey design is pretty awkward overall and even though its a very stable plane to fly, this will only be true if you hit that weight/size sweet spot I mentioned before.

 

[Dreamwalker]

First off, let me say , an excellent job on building that plane!:applause:

At less than a 24"wing span and being as heavy as it is, it will fly, just quickly.
It might not glide as well as the full size one though.

Lighter is always better!
My thought would be to go with a smaller motor like a 24 gram "Blue Wonder" and use a 500 Mah 3S battery.
Right there is a loss of a good 25 grams of weight.

Let us know how the maiden goes, then you can assess what may or may not need adjusting.

Good luck!

Tom

 

[Ron B]

Have you flown it yet?