Official Freewing Twin 70mm AL37 Airliner Thread

[Straightshooter]

[Scale Freak]

If anyone has fitted their AL37 with a flight director or gyro, id like some advice on how this was done. I am fitting a Kopliot to my new one as the last one got away and I lost orientation. The return to home function is what I want to have in place now.

[xviper]

If anyone has fitted their AL37 with a flight director or gyro, id like some advice on how this was done. I am fitting a Kopliot to my new one as the last one got away and I lost orientation. The return to home function is what I want to have in place now.

I've put many gyros into my planes and have a HobbyEagle in my AL-37. I also use the Bigaole RTH device in all my sailplanes. Each type of device will be similar in the way they work and the set up will be "similar" but the best way to make your particular one work is to read the instructions or find a YouTube video the will take you through the steps. Generally, the gyro or flight controller goes between the RX and the servos for AIL, ELE and RUD. Set moderates gains for each axis so you can see how each control surface is reacting and make any changes for response direction as needed. For the actual flight, dial back the gains to a lower setting, somewhere around 25% and increase after each flight till you get oscillation in that control surface, then dial it back a bit. For RTH to work, usually a switch is assigned and this is where reading the instructions comes in. Most RTH devices primarily use AIL and ELE to get it home, although the AL-37 can use RUD gyro to help with the tail waggle. Throw the switch and set throttle to an adequate level for the plane to fly home against the wind (worst case scenario). Always makes sure the gyro works properly and set up properly and then test RTH early to make sure it actually does "come home". Be ready to turn it OFF and manually fly it in the event something isn't set up right.
Having a giant airplane like the AL-37 get away from you and losing it is somewhat hard to do but not impossible. That being the case, a RTH device may not be the solution and perhaps working on other skills might be more important.

[Scale Freak]

xviper, i agree what your saying, but that day I did not listen to my inner voice, which told me conditions were not ideal. I did one flight and it went ok, but I was not on my A game. I went against my better judgement, late afternoon, overcast, grey sky. but wind was ideal and one more battery. It got too far out, and the turn to bring it back I lost orientation. in all the previous 23 flights, i had no issues and loved that plane. That one time, A return to home function would have saved it, and I would use it as an emergency solution to a bad situation, not as a regular go to flying mode. As to the gyro set up, I am familiar as I have one in another plane. I am specifaccly asking about hooking it up in the AL with regards to that control box.

[xviper]

xviper, i agree what your saying, but that day I did not listen to my inner voice, which told me conditions were not ideal. I did one flight and it went ok, but I was not on my A game. I went against my better judgement, late afternoon, overcast, grey sky. but wind was ideal and one more battery. It got too far out, and the turn to bring it back I lost orientation. in all the previous 23 flights, i had no issues and loved that plane. That one time, A return to home function would have saved it, and I would use it as an emergency solution to a bad situation, not as a regular go to flying mode. As to the gyro set up, I am familiar as I have one in another plane. I am specifaccly asking about hooking it up in the AL with regards to that control box.

A flight controller such as a RTH device hooks up similar to a gyro. In fact, it's just a slightly modified gyro. It goes between the RX and servos.

[Scale Freak]

xviper, I get that, but with the AL37, the ailerons they are fed by that ribbon cable from the control box. So, do I disconnect the signal wire and leave the power wires to the servos, or just find the aileron and throttle servo wires in the wing and route them to the gyro, bypassing the control box totally? I'm looking for AL37 specific gyro hook up advice.

[xviper]

xviper, I get that, but with the AL37, the ailerons they are fed by that ribbon cable from the control box. So, do I disconnect the signal wire and leave the power wires to the servos, or just find the aileron and throttle servo wires in the wing and route them to the gyro, bypassing the control box totally? I'm looking for AL37 specific gyro hook up advice.

Don't take apart the servo lead. Use extensions. from the wing root. You can remove the servo lead from behind that multi-connector on each wing.
You have a choice. Remove the AIL feed from RX (coming from the box) and put the gyro/RTH device in between OR, you can bypass the box and do it that way. In either case, the gyro goes between the RX and the servos. Don't worry that there's a control box in that path. Bypassing the box means you have to take the servo feed at the wing on each side and use a "Y" inside the plane. Now you need to decide which route you want to take. Do you trust the control box or not?

[MeyerVW]

I just bypassed the box for ailerons and flaps. Easy. Unscrew the 2 screws on tge wing for the circuit board un disconnect the aileron sevo. Exstension and put the board back. If you also do flaps you need more y harnesses. But for just tge ailerons just 1 y harness will do. Take you mabe 10 minutes to do thiis just as xviper said. I only dud it because what I discovered. Makes sence if tge all share a common ground or power and they may. Also maybe why other aircraft suddenly roll over and lawn dart.

[Desolation Angels]

Thought I’d try a Western Airlines Bud-Lite scheme.

She's gorgeous!
Beautifully done phaehv!

[luca]

Just another useless footage of my AL37 in Alitalia scheme... damn, now Alitalia has closed, I need to repaint in new ITA Airlines scheme 😀

[Aros]

Nice work! Hey as long as she landed in one piece that's what I call a perfect landing!

[GliderGuy]

Worth repeating from the MiG forum…

I will share how I repair EDF fan small nicks caused by FOD. No guarantees that fan blade breakage will be prevented by using this technique. Use at your own risk.

I use a UV activated glue pen.
1) Clean the nick with isopropyl alcohol
2) Apply a tiny drop of the UV glue into the nick
3) Cure with UV light…gets rock hard!!
4) Carefully sand smooth and to shape without removing blade material

The AL37 is prone to ingesting FOD kicked up by the nose wheel. I have successfully fixed several nicks without upsetting the balance of the fan and getting vibrations.

I glue fine grade sandpaper to a popsicle stick so I can reach into the front of the fan more easily. Take your time.

This is the one I use…not cheap, but good stuff. There are many brands available, however.


https://www.amazon.com/dp/B00UAH19FS...ing=UTF8&psc=1

-GG

Caution: The UV curing process is exothermic. If you get uncured glue on your skin and UV light hits the glue, it isn’t pleasant. HOT is the word!

[andynez]

Has anyone swapped out the outrunner motors for the inrunner motors. The originals had a black wire and the new inrunners have a white wire, I'm assuming they are the same..........right?

[andynez]

Has anyone had trouble with the decals. I'm putting them on and all the doors do not want to stick. I'm thinking about hitting them with a clear spray but not sure if the surface is flat or satin. Also what paint would not destroy the foam or paint or decals.

[GliderGuy]

I painted the entire bird with this / several suggested this in various forums. UV protection and non-yellowing. Holds the decals on….


-GG

[MeyerVW]

I did not have issues with them. They stuck too well. However if you do use a clear coat the minwax water based polycrylic. I have used it and it is foam safe. Water based polycrylic.. You can use the satin and it looks good. I used the gloss and it looks good too.

[dries_neyrinck]

This is not my plane, but a clubfriend transformed his AL37 in Swiss livery. Very clean, sober livery but it works :-)



I made a small video for him, way to cool to leave the footage unused

[GliderGuy]

Reporting on results…..

In some prior posts, I have presented the methodology and reasons for adding carbon rod reinforcement glued to the inside of the wing’s wiring channel…glued to the topside skin. Thought you would be interested in the results so far after several hundred flights….aerobatics included...on the current/newest AL-37.

One small stress compression feature has developed in an area on the left wing that is not supported by the added internal square carbon rod.

The wing condition is solid evidence that the extra stiffening of the top wing skin from the motor mounts to the root IS WORKING WELL!
The right wing is still without stress features. Both wings have been painted with water base UV protective paint, in case you notice an odd look to the skin in the photos.

NOTE: The photo with the small compression feature shows the approximate location of the internal carbon rod marked in black for visualization purposes.

See prior posts for the 'HOW TO DO IT" for adding the internal bracing.

-GG

LEFT WING IN A PRIOR BIRD WITHOUT INTERNAL BRACING....
Note: Attempts to repair the cracks didn't work and the paint didn't match.
This bird was finally retired to a spare parts status. Cracks got too ugly.





RIGHT WING…CURRENT BIRD WITH INTERNAL BRACING AND MANY, MANY FLIGHTS



LEFT WING….CURRENT BIRD WITH INTERNAL BRACING. The wing has one tiny compression stress feature.

The sketched-in black diagonal line is the approximate location of the internal carbon rod brace.

[MeyerVW]

Reporting on results…..

In some prior posts, I have presented the methodology and reasons for adding carbon rod reinforcement glued to the inside of the wing’s wiring channel…glued to the topside skin. Thought you would be interested in the results so far after several hundred flights….aerobatics included...on the current/newest AL-37.

One small stress compression feature has developed in an area on the left wing that is not supported by the added internal square carbon rod.

The wing condition is solid evidence that the extra stiffening of the top wing skin from the motor mounts to the root IS WORKING WELL!
The right wing is still without stress features. Both wings have been painted with water base UV protective paint, in case you notice an odd look to the skin in the photos.

NOTE: The photo with the small compression feature shows the approximate location of the internal carbon rod marked in black for visualization purposes.

See prior posts for the 'HOW TO DO IT" for adding the internal bracing.

-GG

LEFT WING IN A PRIOR BIRD WITHOUT INTERNAL BRACING....
Note: Attempts to repair the cracks didn't work and the paint didn't match.
This bird was finally retired to a spare parts status. Cracks got too ugly.





RIGHT WING…CURRENT BIRD WITH INTERNAL BRACING AND MANY, MANY FLIGHTS



LEFT WING….CURRENT BIRD WITH INTERNAL BRACING. The wing has one tiny compression stress feature.

The sketched-in black diagonal line is the approximate location of the internal carbon rod brace.

I have a spare wing if you only need the one half to make it fly.

[GliderGuy]

Thank you MVW...The other wing on the old bird is also full of cracks. I'm keeping the old bird for spare parts (other than wings...LOL) to help keep the new bird going, as needed.

Much appreciated.

-GG