Official Freewing Twin 70mm AL37 Airliner Thread

[GliderGuy]

Especially for those of you getting new birds (or anyone), if you will insert a small carbon rod or square or tube in the wiring channel that extends from the root of the wing and make it long enough to extend past the motor mount...and epoxy glue it to the top of the wiring channel, it will prevent this from happening...see photo. I retired this bird and got another one.

After several hundred flights on the new one...not a single ripple or crease in the top skin. The addition of the internal carbon reinforcement REALLY works. If you do this reinforcement, your top wing skin will stay in like new condition.



This bird was retired after about 2,000 flights even though the cracks aren't of structural concern, since the main loads are handled by the main wing spar. But, they sure don't look pretty.

-GG

P.S. Yes...I did aerobatics with the bird. But I also do them with the new bird. The wing skin on the new bird is staying perfect...due to the carbon glued inside the wiring channel to the foam that forms the top wing skin.

I did attempt to fix the cracks, but failed. They came back and just kept getting bigger. Paint didn’t match....LOL

[GliderGuy]

Sadly Bird#2 is in the spare parts pile. Great day for flying....calm and upper 50s.

I got distracted and hit a light pole. I hate that when it happens. Total loss but lots of spare parts.

AL37 #3 on order. I did get about 300 flights on #2, so a reasonable cost per flight was achieved.

A wise person once told me, “Don’t fly RC if crashing upsets you. YOU WILL CRASH!”

-GG

[Hugh Wiedman]

Sadly Bird#2 is in the spare parts pile. Great day for flying....calm and upper 50s.

I got distracted and hit a light pole. I hate that when it happens. Total loss but lots of spare parts.

AL37 #3 on order. I did get about 300 flights on #2, so a reasonable cost per flight was achieved.

A wise person once told me, “Don’t fly RC if crashing upsets you. YOU WILL CRASH!”

-GG

Love your attitude, we should all take that page from your book. We've all been there and WILL return again, so in the meantime, my condolences on the loss of a friend, AL37 #2. The good news is AL37 #3 will have a well stocked inventory of parts.

[GliderGuy]

Thanks Hugh...I'm betting Bird #3's build will be EASY and even a better bird will result. Might even try it blind folded.....NOT.

-GG

[406PIlot]

Must be a great bird if your getting #3. I think i made the right choice picking up this one. Mine will hopefully be here tomorrow or monday. Can't wait to get this together and in the air.

[GliderGuy]

Must be a great bird if your getting #3. I think i made the right choice picking up this one. Mine will hopefully be here tomorrow or monday. Can't wait to get this together and in the air.

Hi 406P - I would rather still be flying #2! But, lamp posts are unforgiving. Darn it!

But yes...she’s a beauty in the air, fast when driven hard, and a crowd pleaser!

I suggest you take the time to read ALL the posts in this AL37 forum and learn from others before you maiden it. Tons of knowledge here.

Take off with 1/2 flap, land with full flap. I cruise at 1/2 throttle to get reasonable flight times. Reduce to about 1/4 power on base and keep that on final...gradually reducing to cut-off once down low. She does better with a touch of power into ground effect.

Start with about 1 to 2 mm of up elevator trim as viewed at the tip. No flap/elevator mix. A bit of expo on the ailerons is suggested. She can be twitchy on the ailerons until you get used to it or without expo. Expect to add up elevator in turns.

If you ever get a main gear failure, land all wheels up. Otherwise, like I had happen, the low nacelle can dig in and rip off and flip her over. Keep her level at touch down, and find a hard surface, if possible. Turf can grab a nacelle.

Read about the RF chokes (search ferrite or choke). My experience with high current ESC birds is: fly without them and risk a lost bird. Once I started using them on high current ESC birds, no lost birds due to RF noise in the system. I lost a few birds before I began to use RF chokes.

She handles wind pretty well, but cross winds are a trick. If you ever snap off a winglet (very rare), do not fly with just one. She will try to roll hard over if you do fly with only one.

Finally, add the internal wing bracing I discuss above to avoid foam-cell boundary cracking, if you plan to do aerobatics.

She does a nice snap roll and spin recovery perfect. Loops, rolls...

Keep us posted....have fun.

-GG
Amazon link to some RF chokes...the variety is nice and useful.

https://www.amazon.com/Yarachel-50PC...4434775&sr=8-4

[406PIlot]

Fedex tracking still says scheduled delivery today. I'm just chomping at the bit for this thing to get here. I can't wait to get it together and in the air for the first time. I feel like a little kid waiting for christmas morning.

[406PIlot]

Arrived today! Slowly getting started on the assembly. I took some suggestions to add in additional carbon re-enforce the fuselage where the two sections join together. Seems pretty solid. Now i'm just trying to decide if i'll bypass the blue box or not.. What an impressive model when it's out of the box an actually on the table.

[GliderGuy]

Arrived today! Slowly getting started on the assembly. I took some suggestions to add in additional carbon re-enforce the fuselage where the two sections join together. Seems pretty solid. Now i'm just trying to decide if i'll bypass the blue box or not.. What an impressive model when it's out of the box an actually on the table.

Good deal...that will prevent splitting.

-GG

[406PIlot]

Well my new AL37 is assembled and almost ready to go. I just need to double check travel on control surfaces and program my rates (high / mid / low). The book gives the exact same travel for high and low rates for all surfaces. Pretty sure that's a misprint of some kind.

I need to go back through this thread and see what other people are using for their rates.

Hopefully my graphics from Callie will be here by the end of the week.

[GliderGuy]

AL37 arrived today....that was FAST! Got the fuselage together, put the decals on and receiver/wiring done. Added the fuselage topside short carbon rod EXTRA bracing at the fuselage joint to help ensure the halves don’t come apart at the top on hard landings.

Put a small RF choke in the tail...running elevator and rudder wires through it. Secured the rear fuselage wiring so it doesn’t flop about. Then I added another small choke by the green toroidal ring. Since there is room, next step will be to remove the battery tray and install chokes on both sides of the ESCs. Overkill, but Bird #1 flew trouble free (radio wise) for 2,000+ flights with all these RF chokes. Not gonna mess with success.

Trying to have it ready by this weekend and the forecast good weather.

Tomorrow...Painting silver on the leading edge flaps area and the silver anti-icing on the horizontal stab’s leading edge. After that, I will add the internal carbon reinforcement to the wing’s wiring channel to avoid the top wing skin cracking I saw develop on Bird#1 on the motor mount area. Then final assembly, an overall coat of water base SPAR URETHANE, and I will be done.

My goal is a Saturday maiden.

-GG

[406PIlot]

Was going to maiden today, but the wind ended up being a bit stronger than reported by NOAA and multiple other sources. So I ended up holding off. Weather is supposed to be better tomorrow so going to attempt the maiden in the afternoon. Hopefully the weather holds up so I can get this bird in the air.

[Scale Freak]

406Pilot, good call. I had to wait almost 3 months to maiden my Al37, but the wait for prime conditions was well worth it. You don't want to test fly this type of plane and have to fight the elements at the same time. Regarding your question on rates, I have none set on mine, just the one rate and for me, its really no issue.

[406PIlot]

406Pilot, good call. I had to wait almost 3 months to maiden my Al37, but the wait for prime conditions was well worth it. You don't want to test fly this type of plane and have to fight the elements at the same time. Regarding your question on rates, I have none set on mine, just the one rate and for me, its really no issue.

Are you just using the "high" rates as per the manual?

[xviper]

Well my new AL37 is assembled and almost ready to go. I just need to double check travel on control surfaces and program my rates (high / mid / low). The book gives the exact same travel for high and low rates for all surfaces. Pretty sure that's a misprint of some kind.

I need to go back through this thread and see what other people are using for their rates.

I doubt it's a misprint. They are "recommendations" and initial trial and error as everyone has different throws for their planes, so it shouldn't matter what others use to fly their planes. This plane is so benign in the roll and pitch that one rate is a good starting point. When faced with this kind of information, one needs to use a little deductive reasoning and common sense. Since you have a TX with 3 possible rates, you can dial in the only given rate as "middle". Then you can dial in a lower rate and a higher rate.

[Scale Freak]

406Pilot, yes all set up as per the manual. one thing I did do, to try out this flying season, is increase the flap travel by 20%. As I fly off grass, I'm hoping it will get the plane up sooner. At the moment, it takes around 250ft to take off, i want to see if I can get it off a bit faster.

[406PIlot]

Well I got out today and did the maiden today. This plane is an amazing flyer. I have fallen in love with this thing!!! Did the maiden then put in another 7 flights on it. Touch and go wheelies machine!

Got a ton of compliments on landings. This plane makes it so easy. The look of it in the air is something else. It has a huge realisms factor...

Can't wait for my graphics to get here from Callie. Looks good in white, but once windows and everything are done it's going to be even better.

[GliderGuy]

Congrats 406P! Glad you like it.

I am up late....just finished putting the wings on after adding the extra carbon square tubing in the top of the wing wiring channel to keep the top thin skin from cracking over the motor mount area like my #1 AL37 did.

Did some detail painting, too, before tail and wings went on. Got the RF chokes on the ESC wiring under the battery tray.

Other than installing pushrods and giving her an all-over water base clear/satin Urethane anti-UV paint job...a range check + maiden on Saturday will happen.

Calibrated the ESCs and checked all servos functioning. Soooo close. Ready to get her in the air.

-GG

[GliderGuy]

406Pilot, yes all set up as per the manual. one thing I did do, to try out this flying season, is increase the flap travel by 20%. As I fly off grass, I'm hoping it will get the plane up sooner. At the moment, it takes around 250ft to take off, i want to see if I can get it off a bit faster.

Hi SF - Short field training I received years ago proved the book theory correct. Lift only increases to 10 to 15 degrees of flap. After that amount of flap, drag significantly increases and lift only increases a little more.

The shortest take off distance is achieved with 10 to 15 degrees of flap. Add more than that, and the drag hinders acceleration....you won’t clear the trees.

Also, stall speed only decreases a little with more than 10 to 15 degrees.

Your best bet is to set 10 to 15 degrees of flap on take off. This will get you in the air in the shortest possible distance.

Think about it....you ever see a commercial airliner take off with lots of flaps? Nope! They reserve lots of flap for landing....when they need the added drag.

A Cessna 152 may not even fly with lots of flap set for take off...especially when heavy and on a hot day. That huge amount of drag that happens with more than 10 to 15 degrees is a take off performance killer! This aerodynamic principle should apply to model planes, too.

-GG

PS - If you watch carrier jet launches, some birds have full flap. I can only assume the huge thrust to overcome the large drag is a compromise to achieve as large a margin above stall as possible. Any former or current Navy pilots to comment on the full flap configuration off a CAT launch? Acceleration is NOT an issue....LOL!

[406PIlot]

Callie shipped out my graphics today! It's a bit windy today, but i'm itching to get this thing back in the air. I just can't believe how much I like the AL37. I am extremely surprised. Such a great flyer.

I can't say enough good things about this plane.