Official Freewing 80mm EDF L-39 Albatros Thread

[Bellke]

Lost my L-39 at the weekend in the desert. flew too far out for the return leg for landing and in the heat haze/dust it just disappeared! i cut the throttle and hoped for the best after waiting a few seconds to see if the haze cleared but it never appeared again, after 2 1/2 hours walking in the dubai desert with no water i had to give up before i became a victim of the heat myself. Damm i miss this jet was a wonderful aircraft to fly.

I can sympathize, I lost mine in the AZ desert this past weekend after 4 1/2 flights. I was liking it so much though I'm already thinking of another.

[paulrkytek]

First 3 flights with L39 went ok but I prefer the sound of the freewing 80mm so I bought one, installed it, very happy with sound. Not quite the thrust of the fms fan but ok. I asked Motion for performance figures of the 9 blade and was told freewing did not give them any info and they would not give me any esc settings stating that the fan was designed to be used with their esc. I consider that a poor response. How am I supposed to check fan performance if I do not have basic figures ? Here are Freewing figures which I obtained from Ali express within an hour of reading the motion r.c.reply

https://fr.aliexpress.com/item/40010...19419660%22%7D

power meter readings taken this lunchtime in the model, static 24.9v 86a 2013w Turnigy plush 32 120 amp HV esc with 8 amp bec, timing on auto, pwm 12k. moto type edf. Here are the figures from the highlighted Ali Express site :- Fan ref E72313 3658 1920kv 3350-3450 gms thrust 85-91amps 100amp esc wt 285gms 2100 watts

[paulrkytek]

First flight with my L39, lots of stuttering from FMS motor, took out100amp esc and separate bec, installed the following :-
Freewing L39, 1050mm ws 23.6dm2. 3kg with rhino 4000mah 50c battery WL about 130gms/dm2.
FMS platinum pro 3280 2100kv in-runner,ceramic bearings 3.5kg thrust, 120amp Turnigy 32 plus HV 2-8s with 8amp bec esc timing low at 6 deg. Pwm freq 12K.( 52500rpmx4/20 = 10.5and esc card states 8k or 12k ) start up power 10%, brake off , lipo cells on auto, cut off voltage 3.3v, temp protect 140degc. Auto rotation off moto type normal, bec voltage 5.5v Power to weight = 1.15 to 1.0. Full throttle 24.9v 103 amp 2380 watts static on power meter.
Balanced fan with table vibration method,running smooth now, any thoughts before I take to the skies again ?

[Gripper39]

Lost my L-39 at the weekend in the desert. flew too far out for the return leg for landing and in the heat haze/dust it just disappeared! i cut the throttle and hoped for the best after waiting a few seconds to see if the haze cleared but it never appeared again, after 2 1/2 hours walking in the dubai desert with no water i had to give up before i became a victim of the heat myself. Damm i miss this jet was a wonderful aircraft to fly.

[SanExup]

Prop planes I use less expo.

[SanExup]

I use some receiver's with as3x and on EDFs I use 30% expo. I'm the opposite, I use 40% expo on the rudder/nosewheel usually with 100% travel but it's plane dependent.

[steven gubala]

ok got you xviper, thanks for your input

[xviper]

what is everyone using for expo on their planes? I'm using a spektrum dx9 transmitter and a spektrum AR 637T receiver, any help would be great.

Expo is a very personal thing and you have to experiment to see what feels right for you. This L-39 is a very stable airplane and responds well to direct inputs. However, typically, I dial in about 20 to 25% expo on the AIL, ELE channels. I use very little to no expo on the RUD. Some would find that excessive while others really could use even more. Consider also, that when using a 637T and utilizing SAFE, stick inputs in SAFE will be greatly reduced just by nature of SAFE. Even in AS3X, expo may not translate well.

[steven gubala]

what is everyone using for expo on their planes? I'm using a spektrum dx9 transmitter and a spektrum AR 637T receiver, any help would be great.

[paulrkytek]

My calculations showed 100%, there's really no noticable difference during take-off.

You are probably more accurate than me, I used a tape and guessed on the safe side for the d shaped ducts, my fan calc is accurate for the fms fan

Freewing L39 Albatros 80mm edf, 1055mm span 1351mm length 2200gm dry weight, FMS 80mm 12blade edf (320gms)with 6s 3280-2100kv inrunner producing 3500g thrust. weight with 4500mah 40c zippy compact s (720g) AUW incl rx &bec 2965gms power to weight = 1.18 to 1.Cheeter fan 3300mm2, cheeter fan with mesh 2300mm2.main inlet ducts3250mm2 fan dia area 5025mm2, motor area 960mm2 so fan swept area4065mm2. inlet air with mesh covered cheater fan 5650mm2. separate BEC set at 5V.

[Radar-Guy]

My calculations showed 100%, there's really no noticable difference during take-off.

[paulrkytek]

There is no need for any auxiliary air inlets. I‘ve got two FW L-39 and both have the heater hole closed from both sides. I‘m flying off grass and tried it with a couple of different fan setups.

Well its done now and it wont do any harm and gives me peace of mind. The way I see it there was no point in Freewing putting an air transfer hole between the nose compartment and the cabin and not providing a clear way to get the air in from the outside. If you have closed the cheater hole from both sides that means the air intake area from the 2 main side inlets will be around 80% of the swept fan area which I would have thought would have had a bit of an impact on initial take off thrust, but hey what do I know !!!

[Radar-Guy]

There is no need for any auxiliary air inlets. I‘ve got two FW L-39 and both have the heater hole closed from both sides. I‘m flying off grass and tried it with a couple of different fan setups.

[paulrkytek]

Finally opened up the Albatros box, fitted the fms pro platinum series 80mm in-runner ( 2100kv 3.5kg thrust ) added the frying pan mesh guard to the cheater hole, painted the servos and connectors grey and added an air intake hole and an air scoop ( cut down a small spinner nose) mainly because Freewing went to the trouble of adding an air intake hole which clearly worked with gear down but not so good with gear up and gear door closed. Now all I need to do is add 6mm ply restraint/ v shaped centering piece to rear of nose leg and wait for the 30mph winds to subside before maiden flight later this week. I will be using Rhino 4000mah 50c packs and expect to get 3 to 3.5 mins flight time but I have a separate 6 to 10 amp BEC set to 5v output with with 370mah 2s lipo ( I normally use about 75mah per flight and swap after 2 flights.)

[SanExup]

It might just be whatever paint they had on hand at the moment. But maybe there is a rhyme and reason.

[wvrailfan]

Thanks guys.

I got it together and maidened this evening. I'm happy to report all went well. It flies a lot like my T-33, which is one of my favorite planes.

I took the liberty of adding a tail light at the top of the vertical stab and a Flytron strobe to the bottom of the fuse, for late evening flying.

JB

[DCORSAIR]

I'm late in joining the L-39 party, but as of this week that has been corrected.

I've skimmed this thread as well as the RCG thread, but just wondering if anyone here has the Cliff Notes rundown on the camo scheme? Is it an airshow only scheme or an actual military livery?

JB

When I bought mine, I did find a picture of the real one as a military trainer I think it was, only thing is the pictures on the MRC page makes it look to have more brown on it, I thought it was more of a desert camo but it is more of a green camo, little more green than I wanted but it still looks great though.

[SanExup]

I believe it is a Russian naval aviation scheme. Though some private owners do also fly with the scheme.

• Fan favorite camouflage paint scheme based from the 444 TsBP i PLS (Combat and Conversion Training Center) Ostrov Air Base, Russian Naval Aviation

[wvrailfan]

I'm late in joining the L-39 party, but as of this week that has been corrected.

I've skimmed this thread as well as the RCG thread, but just wondering if anyone here has the Cliff Notes rundown on the camo scheme? Is it an airshow only scheme or an actual military livery?

JB

[Twowingtj]

A larger, heavier pack just requires more energy to fly. The best bang for the battery is throttle management.

Anything over 85% throttle pulls the battery down quickly and yields little extra performance. When at a higher altitude, point the nose down a bit and let the weight of the plane do the work while having throttle at near idle. Then throttle up as needed.

Fast passes are fun, but a little more cruise mode flying will enable 4+ minutes flying time.