Official Freewing Twin 70mm AL37 Airliner Thread

[ndrew3]

Finally finished mine up! Pretty happy with it, definitely a couple mistakes though.

Made a little build video as well just for the hell of it: https://www.youtube.com/watch?v=i6Uo4oOMESE

[vduniec]

Nice shot, but I can’t tell if you painted it silver...or is still white? If it’s painted silver, what paint did you use?

Thank you.

I sprayed it with spray paint. The color is called Aluminum. The wings, engine pods, cargo doors and empennage are painted Boeing Aircraft Company Gray. I gave Home Depot the Federal Standard number for it and they color matched it in paint sample. FS 16515.

If I were to paint it again, I’d select the Chrome Silver color. The Aluminum is too grayish and dull to my eye.

[ndrew3]

Has anyone had issues with the back half of the fuselage kinda falling off/drooping down? I took a pretty big slam on my maiden flight landing after the battery shifted forward, glued it back up and it happened again on my next flight with a much better landing. The 2 carbon spars through the fuselage are fine and not cracked or anything, but still doesn't seem super solid.

I just went through and lined the inside where it meets with packing tape which should help, but is this common for you guys? Anything else you've done to strengthen that area where it connects?

[GliderGuy]

Has anyone had issues with the back half of the fuselage kinda falling off/drooping down? I took a pretty big slam on my maiden flight landing after the battery shifted forward, glued it back up and it happened again on my next flight with a much better landing. The 2 carbon spars through the fuselage are fine and not cracked or anything, but still doesn't seem super solid.

I just went through and lined the inside where it meets with packing tape which should help, but is this common for you guys? Anything else you've done to strengthen that area where it connects?

Yes….known issue and discussed in this thread. A proven solution is (before assembly) to insert some short carbon rods into the fuselage top near the top center…one piece on each side of top center. The side rods are not sufficient unless you did an excellent job of gluing this fuselage joint. Typically, a perfect glue job is not made.

Post assembly, however, your option is to glue in several pieces of bracing inside and in several places along the seam from the top around to the sides. I even did this with hot glue, but CAUTION you can get a bad burn.

Packing tape may not be the best answer…needs to be a more permanent fix. This joint sees a lot of stress.

Check the bottom of the fuselage, you may find compression fractures. I had to add some external bracing there, too. But…the bottom is out of sight.

If you are good at cosmetic skills, you can trench each side of top dead center of the outside of the fuselage and insert/glue in some carbon or plywood into the trench. Fill/sand/paint - Could even use the white tape provided in the kit to cover your work.

Bottom line….make it STRONG by any method you choose. Tape is NEVER a permanent fix for anything.

-GG

Perfect matching paint / Home Depot

[ndrew3]

Yes….known issue and discussed in this thread. A proven solution is (before assembly) to insert some short carbon rods into the fuselage top near the top center…one piece on each side of top center. The side rods are not sufficient unless you did an excellent job of gluing this fuselage joint. Typically, a perfect glue job is not made.

Post assembly, however, your option is to glue in several pieces of bracing inside and in several places along the seam from the top around to the sides. I even did this with hot glue, but CAUTION you can get a bad burn.

Packing tape may not be the best answer…needs to be a more permanent fix. This joint sees a lot of stress.

Check the bottom of the fuselage, you may find compression fractures. I had to add some external bracing there, too. But…the bottom is out of sight.

If you are good at cosmetic skills, you can trench each side of top dead center of the outside of the fuselage and insert/glue in some carbon or plywood into the trench. Fill/sand/paint - Could even use the white tape provided in the kit to cover your work.

Bottom line….make it STRONG by any method you choose. Tape is NEVER a permanent fix for anything.

-GG

Perfect matching paint / Home Depot

Yeah, I have a couple of decent pieces of wood I was thinking of using as spars for the top and bottom, think that should help a decent amount. Glad to know it wasn't just bad assembly on my part, but wish I would've known before I assembled it! Thanks, man

[GliderGuy]

Don’t feel bad - I broke my #1 AL37, too. Same thing / hard landing. Take heart. After bracing was added, I flew her until I wore her out. No more fuselage issues.

Also, suggest you read:

https://www.hobbysquawk.com/forum/rc...176#post301176

https://www.hobbysquawk.com/forum/rc...435#post301435


-GG

[ndrew3]

Don’t feel bad - I broke my #1 AL37, too. Same thing / hard landing. Take heart. After bracing was added, I flew her until I wore her out. No more fuselage issues.

Also, suggest you read:

https://www.hobbysquawk.com/forum/rc...176#post301176

https://www.hobbysquawk.com/forum/rc...435#post301435


-GG

Took your advice and added some more internal support with a few wooden spars glued around the seam, and my third flight felt awesome and completely locked-in. I had some issues with the battery moving and shifting the CG a bit on the first 2 flights as well, but have that sorted now too. Appreciate the help! Here are the 2 sketchy first flights, ha:

[xviper]

Took your advice and added some more internal support with a few wooden spars glued around the seam, and my third flight felt awesome and completely locked-in. I had some issues with the battery moving and shifting the CG a bit on the first 2 flights as well, but have that sorted now too. Appreciate the help! Here are the 2 sketchy first flights, ha:

Never could quite understand why the tail end would bend and fall off. Then I see in your video that you don’t use the tape that comes with the plane. I’ve had some fairly hard landings but not to the extent that your video shows. I think the tape helps. I’ve never had any indication that the tail end on mine has ever even thought about bending.

[GliderGuy]

Never could quite understand why the tail end would bend and fall off. Then I see in your video that you don’t use the tape that comes with the plane. I’ve had some fairly hard landings but not to the extent that your video shows. I think the tape helps. I’ve never had any indication that the tail end on mine has ever even thought about bending.

From each side carbon rod up to the top center and over to the other side carbon rod is an unsupported glue joint as you know.

It’s all a matter of how well the assembler makes this glue joint. Did they score the faces of the foam with a razor knife? Did they use sufficient glue? Etc…. The variables can make for a weaker glue joint.

A hard landing, or multiple hard landings, or a moderate crash into an unseen hole (YouTube video) provide sufficient stress to open this glue joint.

My #1 AL37 did it, too. I was flying off a short runway area and could not allow ANY float. I had to “drop her in” so to speak. The glue joint opened up after several landings. Repair included adding internal braces across the seam.

After I wore out #1 and retired her, #2 bird got the carbon rod treatment. I drilled two small diameter holes into the foam running parallel to the side carbon rods but located on either side of top dead center of the fuselage about 2 inches apart from top center. I also read about scoring the foam faces of the joint. When all this went together, now there were 4 carbon rods supporting the joint. 2 small ones about 4 inches long each at the top and the 2 long side rods. Actually, even hardwood dowel rods would work. Anything to strengthen the bare glue-only joint across the top.

This glue joint isn’t about to split now….cosmetic joint tape added or not.

As posted prior, pilot error and the distraction of a non-extended main gear lead me to fly #2 bird into a lamp post. UGH. Total loss. I can happily report #3 bird got the same carbon rod treatment at the top and isn’t showing any signs of splitting even after several hundred flights.

Also, posted earlier, addition of carbon glued onto the top skin of the wing INSIDE the wing wiring channel is a proven way to prevent foam cell boundary cracking on the top wing skin. Bird #1 was retired because of this…got too ugly to look at….see below (my poor attempt to repair the cracks didn’t work).

#3 isn’t doing this. Even after lots of non-scale aerobatic flying. The added carbon inside the wing wiring channel works like a charm.

-GG

[Scale Freak]

It is with a heavy heart that I pass on the untimely passing of my beloved AL37. I took it up a couple of days ago and flight #1 was good, but I could feel I was not on top of my game. I debated about doing another flight, and the conditions were just perfect and getting better, other than the sun was not quite setting, but on its way. still plenty of light though. But, myself, I was not up to the standards I liked but regardless, went up a second time. It got too far away, and turn to final, I lost perspective and in it went. No one to blame but my own self. I broke my own rule with this plane, that if I was not feeling it, I would not fly it. So, after 22 flights, its gone, and i'm upset at myself for crashing one of my favorite planes.

[Hugh Wiedman]

It is with a heavy heart that I pass on the untimely passing of my beloved AL37. I took it up a couple of days ago and flight #1 was good, but I could feel I was not on top of my game. I debated about doing another flight, and the conditions were just perfect and getting better, other than the sun was not quite setting, but on its way. still plenty of light though. But, myself, I was not up to the standards I liked but regardless, went up a second time. It got too far away, and turn to final, I lost perspective and in it went. No one to blame but my own self. I broke my own rule with this plane, that if I was not feeling it, I would not fly it. So, after 22 flights, its gone, and i'm upset at myself for crashing one of my favorite planes.

So sorry to hear that, there's only one thing left to do. Get another. I've done that with other planes, getting them too far out and loosing orientation, but sometimes just can't get my brain to learn from my numerous mistakes. I feel your pain, and this added to the early first round exit of the Oilers (along with my Panthers)!

[GliderGuy]

Ouch! What he says….GET ANOTHER. When I stupidly flew my second brand new AL37 into a lamp post, #3 is since doing great and giving me a lot of joy.

Someone posted in this thread…”If you ain’t crashing, you ain’t flying!”

-GG

[Flamingo]

MAIDEN ALREADY
Airforce one with NEW design

from my friend, mine is in background

we like them🤩 flying regularily since 1.5 years from grass
w/o any issues
use just big batteries up to 8.8Ah and extended battery bay

[ABJ]

Ready to maiden my AL37 in SAS scheme, have been reading this tread through for info an battery size and im planning to use 2 x6S 70C 4000Mah bats in parallel, mainly because i have a bunch of them on stock. i have modified the battery tray to be able to place batteries further back to balance on the factory CG. It balances perfect and ends up at 4800Grams in total weight.

? please share if you have any experience flying with dual bats at around 1240 G for both. and total airplane weight at 4800 G,
Im flying of a need grass surface in my club and my main concern is the stress on the LG with the added weight, Will it hold :-)

[mshagg]

I haven't tried yet but next trip out to the field will be trying 6s4p 4000mah Li ion for hopefully a 15min flight lol. That's about 1800g of battery.


Justin La has a vid on YouTube of a 2x5500RT endurance test and the plane handled it fine. I think managing speed and bank angle in the turns will be more critical than the landing gear - these are some of the best retracts you'll find on an EDF for my 2c.

[ABJ]

I haven't tried yet but next trip out to the field will be trying 6s4p 4000mah Li ion for hopefully a 15min flight lol. That's about 1800g of battery.


Justin La has a vid on YouTube of a 2x5500RT endurance test and the plane handled it fine. I think managing speed and bank angle in the turns will be more critical than the landing gear - these are some of the best retracts you'll find on an EDF for my 2c.

Thanks.. Your setup looks very similar to mine.. Nice to hear the LG's are tough, as im not concerned about the flying as
long as i keep it within the scale flight envelope for a Passenger jet.

Hope to fly tomorrow, will post result
:-) Anders

[xviper]

Ready to maiden my AL37 in SAS scheme, have been reading this tread through for info an battery size and im planning to use 2 x6S 70C 4000Mah bats in parallel, mainly because i have a bunch of them on stock. i have modified the battery tray to be able to place batteries further back to balance on the factory CG. It balances perfect and ends up at 4800Grams in total weight.

? please share if you have any experience flying with dual bats at around 4800G on the airframe. Im flying of grass surface in my club and my main concern is the stress on the LG with the added weight, Will it hold :-)

Two 4000mah, 6s, 70C LiPos shouldn't weigh 4800g. Is your scale calibrated correctly?
Unless you hit a hole or bump in the grass or land real hard and heavy, the gear should be OK. I've done it a couple times with mine but I didn't like it. Lots of grass get sucked into the engines.

PS. Nevermind, you're talking about the weight of the whole plane and batteries.

[ABJ]

Two 4000mah, 6s, 70C LiPos shouldn't weigh 4800g. Is your scale calibrated correctly?
Unless you hit a hole or bump in the grass or land real hard and heavy, the gear should be OK. I've done it a couple times with mine but I didn't like it. Lots of grass get sucked into the engines.

PS. Nevermind, you're talking about the weight of the whole plane and batteries.

Yes.. total airplane weight is 4800G. Batteries alone are 1240 G.
Hope to survive the GRASS experience :-)

[GliderGuy]

A weak area of the LG is the bottom wing skin in front of the main LG. If you have concerns, take a thin sheet of carbon or a good aircraft plywood and cut a piece 3x3 inches or there abouts for each side and remove the paint from the foam in front of each main gear and glue the sheet to the bottom skin either butting up against the plastic mounts forward side or even overlapping onto the plastic mount.

Otherwise, the main gear can pull down on the front side of the plastic mounts and split the bottom skin in the process. It takes a whack to pull the plastic mount down on the front edge, but it can happen. Reinforcing this area can’t hurt.

-GG

[ABJ]

Maiden done, all vent well and my concern about the extra weight by flying with two 4000 MaH Bats proved not to be a problem, only catch was it required a rather long takeoff run, but landing was fine with plenty af elevator authority to flare.. However i found out that supply cable from bat's to ECS got extremely hot, which i think i strange when considering that i only had full throttle during take off, rest of my flight was at half gas, just cruising around .. Flight time with 2 x 4000Mah 70C was 4 mins, and the cells were at 3,75 after..

Im suspecting the factory wire Y connection from ECS to Battery connector might be soldered bad, or just made of to thin wires..

The heat and the power consumption seems strange,,

Does anybody in here have the same heat build up in cables and connectors when flying.. ?
I fly my 6S Freewing Hawk T1 & F-35 frequently and have never experienced warm cables / connectors


:-) Anders