Official Freewing Twin 70mm AL37 Airliner Thread

[mshagg]

+1 it's one of those rare instances where I set the CG according to the manual and left it there. Plenty of stick left to flare with assuming you're carrying power down to the threshold, but she will come in like a javelin dead sticking lol.

Too much flap/ele mix perhaps? Using take off flap setting? They're pretty effective on this thing.

[xviper]

Mine is balanced right on the marked CG and I can touchdown and roll on the mains for a long distance before the nose comes down. Take offs are not excessively long either. You don't say how you are balancing this plane. The CG marks are on the underside of the wing. That's not where you hold it. You hold it upside down. Balancing it right side up is somewhat hard to do as it teeeters too much and you usually get it wrong.

[Speedrick]

Logged 4 flights till now on the AL37.
Moved the battery aft from the recommended CG by 1,5inch. This has a positive impact on the flying characteristics
but still does not allow me to flair during the landing (stick full up!!!!!! and can’t get the nose up) with the recommended throws on the elevator. Also, TO run takes a lot of the length of our runway.

This makes me believe that the CG is still not OK.
As requested previously, is there really nobody willing to share their CG position, measured on the wing?
I presume I’m not the only AL37 pilot, struggling with this.....



Already many thanks for helping,


Eric

[GliderGuy]

Works out to 0.313 oz / sq in

Based on the following:

1 dm^2 = 15.5 in^2

28.4 g = 1 oz

wing area = 36 dm^2

4962 / 36 = 137.8 g / dm^2

137.8 / 28.4 = 4.85 oz / dm^2

4.85 / 15.5 = 0.313 oz / in^2

[Scale Freak]

I'm actually just trying to confirm my calculations. My plane has come in at 4962g all up flying weight, and with the wing area of 36 dm2, gives a wing loading of 138 g dm2 (44.37 oz/in2 !) or a CWL of 22.9. This seems astronomical considering how nicely it flies. Anyone else do the calculations?

[GliderGuy]

From the manual....

The 110g/dm^2 is calculated with the weight of the battery included.

[Scale Freak]

Anyone calculated the Wing Cubic Loading on this plane?

[DarthSyd]

Thanks Waconut,

I was just worried about the imperfections of the foam showing up, but I'm guessing, like you, that most people have used a gloss clear coat.

Thanks again.

[Waconut]

Darius,
I used a gloss clear coat on mine. It looks really good in the air.

[DarthSyd]

Hi All,

I'm loving all the paint schemes on this AL37, I'm just in the finishing stages of my own (which I will post soon).

Just curious what sort of clear coat sheen levels are people using? Matt, Satin, Semi-Gloss or Gloss?

Cheers Darius

[Straightshooter]

AL37 power consumption using in line amp meter.

[Straightshooter]

For safe transport, Reflectix. Total costs $55.

[Straightshooter]

Thai Airways Suphannahong Royal Barge - inspired by the 777 livery. 6S 6000 with JP Hobby Brakes. Maiden pending at Coachella Valley RC Club, Thermal, CA.

[GliderGuy]

I have 6S 5000 mAh batteries. I am finding that with better throttle management, I am getting up to 4 min with around 35% battery left. I cant see how you would get 10min flight times, so if anyone is please tell me how! I am considering 6000 mAh batteries next to extend the time available.

A 10 min flight, even on 6000s, would require very careful throttle management including a partial throttle take-off and slow flying.

Remember - Long flight times may equate to the following:
- Long recharge times
- Reduced battery life
- Not having a safety net at the end if a go-around is necessary
- Increased chance of battery puffing
- Increased chance of going below the 3.3V minimum battery voltage
- Hot battery... and heat is a LiPo killer
- ESC low-voltage motor shut-down

Shorter flight times allow for a more flexible throttle management with some acrobatics and fast passes.
Target a flight time and style that leaves about 3.7 V cell voltage. Safer and your batteries will love you for it.

-GG

[Scale Freak]

Hi Scale Freak,

what battery capacity are you flying?
They indicate a 10min flight time on a 5000mAh package🤔



Regards,

Eric

I have 6S 5000 mAh batteries. I am finding that with better throttle management, I am getting up to 4 min with around 35% battery left. I cant see how you would get 10min flight times, so if anyone is please tell me how! I am considering 6000 mAh batteries next to extend the time available.

[TwistedGrin]

Sparky and I were able to share the skies together at our club fun fly this week end....pretty cool airshow

TwistedGrin

[themudduck]

Ok,

maidened mine today, with the CG as indicated.
During the take off roll, it became obvious that the CG was way to much fwd.
It was such that I had no more elevator to flair during the landing.
Apart from that, it was a successful maiden flight on the 737 today

have a nice one,

Eric

That is a beautiful job on your plane!! Its stunning!

The marked CG on virtually all FW planes is too far forward, its a "starting point" and virtually all of us prefer to move the CG back. "How far back" depends a lot on what you like in terms of the model's performance. For the AL37, try moving the battery back 5mm on each flight until you like it. Don't go back further than that!

I took an airborne video with my AL37 today. It was quite windy, made all the passengers very sick. But I made a perfect landing on one wheel, then the other one!!

[Speedrick]

Ok,

maidened mine today, with the CG as indicated.
During the take off roll, it became obvious that the CG was way to much fwd.
It was such that I had no more elevator to flair during the landing.
Apart from that, it was a successful maiden flight on the 737 today



have a nice one,

Eric

[themudduck]

FPV flight from yesterday. Much better landing this time. :)

https://youtu.be/F60SMDzYXrw

That was fun to watch, great POV. I like the way the light changed inside the cockpit.

[Jefferybray]

Jeff,
Thanks again for sharing the files. I printed them out but unfortunately, there is a gap along the sides if you if you glue both halves together. I don't think there is enough curvature to the mounting area where the antenna meets the fuselage. I carved a little off of the front and back ends to help and opted to allow for the seam along the top. It'll be easier to fill and sand now. I'm grateful for your contribution and it works for me but just wanted to give you this info incase you wanted to tweak the design a bit. The photo shows the gap after some carving. Prior to, the gap was much larger. Just an FYI.

Thanks for letting me know, I'll create more of a curvature, looking at the pictures I see what you are saying.

Jeff