Great Planes L-39
#126
Senior Member
Join Date: Feb 2008
Location: st. louis,
MO
Posts: 156
Likes: 0
Received 0 Likes
on
0 Posts
RE: Great Planes L-39
Thank guys for you input regarding servos. Interestingly enough, I had a near fatal with my souped up diablo yesterday. Because of servos no less, I was really high, altitude not drugs. I did a split s and dove for the deck, faster than ever before, when I pulled up on the stick, it SLOWLY pulled out of the dive. I attribute this to the force of the wind resistance on the control surface. I am using the stock servos in this plane. I would hate to lose anything L-39 or otherwise because of cheaping out on good parts I will look at the servos you reccommend. Also what type of glue do you all suggest? That may be a silly question but it's more foolish to disregard knowledge and experience of those around you, make sense?
#127
Senior Member
My Feedback: (7)
Join Date: Jun 2003
Location: Joplin,
MO
Posts: 197
Likes: 0
Received 0 Likes
on
0 Posts
RE: Great Planes L-39
I used medium gap fill CA and a little bit of kicker to build mine. Others have used epoxy with no trouble. I used the CA because I don't know about you, but when I use epoxy I think a little is good, running out of the joints must be better LOL. With a 2200 3cell lipo and all the electronics including the bigger motor, mine weighs in at 20oz even RTF.
#128
My Feedback: (7)
RE: Great Planes L-39
My L-39 with the Sparks canopy upgrade flies great, I did install a hotter motor and a paper thrust tube. I have noticed that the hinge on the elevator is starting to disappear. the right elevator has no hinge material from the tip inboard about 3/4 inch. Anyone else having this problem?
#129
Senior Member
Join Date: Nov 2006
Location: St Louis,
MI
Posts: 6,073
Likes: 0
Received 0 Likes
on
0 Posts
RE: Great Planes L-39
ORIGINAL: pkoury
My L-39 with the Sparks canopy upgrade flies great, I did install a hotter motor and a paper thrust tube. I have noticed that the hinge on the elevator is starting to disappear. the right elevator has no hinge material from the tip inboard about 3/4 inch. Anyone else having this problem?
My L-39 with the Sparks canopy upgrade flies great, I did install a hotter motor and a paper thrust tube. I have noticed that the hinge on the elevator is starting to disappear. the right elevator has no hinge material from the tip inboard about 3/4 inch. Anyone else having this problem?
#130
Junior Member
Join Date: May 2008
Location: , MI
Posts: 3
Likes: 0
Received 0 Likes
on
0 Posts
RE: Great Planes L-39
I'm glad to hear that not ALL you geeks are getting plugged in the cornspitter with this rig like I did! See early posts. I bought mine in Portage MI @ Hobbysports.com and have taken it in 3 times to get help, but the thing just wont fly. Now I'm dealing with the company as the choads have no recommendations over here. I have to send it in FULLY assembled with all my gear ($385) with the jet. NICE! that should be cheap! Then wait to find out how I got ganked, and hopefully finally be able to fly when they ship it back with their suggestions. They (Electrify) think it's the ESC (brand new) or the motor. The only thing I can think is that some jacknut put the wrong pitch prop in my package. The motor really screams! That's the ONLY thing these veterans at the shop have suggested after seeing the setup. This is really all very sad IMHO. Again, I'm glad that not everyone is dealing with this...........
#131
Senior Member
Join Date: Feb 2008
Location: st. louis,
MO
Posts: 156
Likes: 0
Received 0 Likes
on
0 Posts
RE: Great Planes L-39
Got mine together today and cant wait to fly it, bit Im a bit conserned about the CG, it's a bit forward because of this 2200 mah battery, Im using a dons wicked extreme 5400kv with a Xf fan setup so it's the battery that is suggested. Ive have used the set up in my diablo and just transfered it to the L-39. I think I'll be OK, some of you all use this kind of setup as well.
#132
Senior Member
Join Date: Nov 2006
Location: St Louis,
MI
Posts: 6,073
Likes: 0
Received 0 Likes
on
0 Posts
RE: Great Planes L-39
ORIGINAL: animal acker
Got mine together today and cant wait to fly it, bit Im a bit conserned about the CG, it's a bit forward because of this 2200 mah battery, Im using a dons wicked extreme 5400kv with a Xf fan setup so it's the battery that is suggested. Ive have used the set up in my diablo and just transfered it to the L-39. I think I'll be OK, some of you all use this kind of setup as well.
Got mine together today and cant wait to fly it, bit Im a bit conserned about the CG, it's a bit forward because of this 2200 mah battery, Im using a dons wicked extreme 5400kv with a Xf fan setup so it's the battery that is suggested. Ive have used the set up in my diablo and just transfered it to the L-39. I think I'll be OK, some of you all use this kind of setup as well.
#133
RE: Great Planes L-39
I fly mine nose heavy all the time, especially on 4S. In fact when going faster I prefer nose heavy as they track better. You just need to hold a little more up on landing that is all.
Don
Don
#134
Senior Member
Join Date: Feb 2008
Location: st. louis,
MO
Posts: 156
Likes: 0
Received 0 Likes
on
0 Posts
RE: Great Planes L-39
Yes, I agree now, I have three flights and have noticed that this plane is more prone to stalling and is not for the beginner, Ive been relatively lucky, only a few small crashes, nothing a little electrical tape and some ca cant fix. But wow what a rocket! The first flight I made I thought, "wow, what have I been missing?" This plane is so wonderful especially when all I can compare it to is that pos, diablo! Which by the way I will be assembling stock and shooting down with the help of my friend and his 12 guage. I just need someone to record it for all to enjoy.
#135
Join Date: Sep 2006
Location: Pewaukee, WI, ALBANIA
Posts: 150
Likes: 0
Received 0 Likes
on
0 Posts
RE: Great Planes L-39
Way to go AA! Didn't I tell you that the Diablo was a turd? I just gutted what was left of mine off the floor this morning and tossed it in the trash. Target practice sounds fun. Shoot some video too. BTW once you get the hang of this one you should try the Twister or my newest favorite jet the Sapac T-45 composit. Boy does that thing scoot!
#136
Senior Member
Join Date: Feb 2008
Location: st. louis,
MO
Posts: 156
Likes: 0
Received 0 Likes
on
0 Posts
RE: Great Planes L-39
Paul, your absolutely right. However, I have encountered some things which I would like to discuss with you all, when cruising along at higher rates of speed the plane seems to wiggle in the air, what's that all about? Also when I do a loop and pull back on the stick too hard when coming out of the loop it sometimes will spin out of control, and I must quickly regain stability. Now I know what your answers will be, if it wants to do that when you pull back that hard, just dont pull back like that, right? I just wondered if anyone else has encountered this, and has anyone had the peice of foam that is held on by magnets above the motor and edf fly off yet? Today as I was really picking up some good speed that thing just blasted off!
And those servo protectors under the wings are not very useful, they keep breaking off when I land.
And those servo protectors under the wings are not very useful, they keep breaking off when I land.
#137
RE: Great Planes L-39
Reduce the up elevator throw as it sounds like your getting a high speed stall. I fly on duals rate on the elevator as I need more up for landing but it is way too much for 100 mph flying.
Don
Don
#138
Join Date: Sep 2006
Location: Pewaukee, WI, ALBANIA
Posts: 150
Likes: 0
Received 0 Likes
on
0 Posts
RE: Great Planes L-39
Right on, too much elevator and it goes into a spin where you run out of altitude and ideas in a hurry. As far as the servo arms busting off, I took a piece of 3/32 light ply and cut a strip that is just as wide as the protector and runs the length of the wing and then glued it to the bottom of the wing. As far as the wiggle that the plane does, that comes from not enough area on the fin. Not a big deal and don't go all Diablo on my by trying to make modifications on it because you'll end up adding weight and that's not a good thing.
Paul
Paul
#139
Senior Member
My Feedback: (7)
Join Date: Jun 2003
Location: Joplin,
MO
Posts: 197
Likes: 0
Received 0 Likes
on
0 Posts
RE: Great Planes L-39
ORIGINAL: animal acker
Paul, your absolutely right. However, I have encountered some things which I would like to discuss with you all, when cruising along at higher rates of speed the plane seems to wiggle in the air, what's that all about? Also when I do a loop and pull back on the stick too hard when coming out of the loop it sometimes will spin out of control, and I must quickly regain stability. Now I know what your answers will be, if it wants to do that when you pull back that hard, just dont pull back like that, right? I just wondered if anyone else has encountered this, and has anyone had the peice of foam that is held on by magnets above the motor and edf fly off yet? Today as I was really picking up some good speed that thing just blasted off!
And those servo protectors under the wings are not very useful, they keep breaking off when I land.
Paul, your absolutely right. However, I have encountered some things which I would like to discuss with you all, when cruising along at higher rates of speed the plane seems to wiggle in the air, what's that all about? Also when I do a loop and pull back on the stick too hard when coming out of the loop it sometimes will spin out of control, and I must quickly regain stability. Now I know what your answers will be, if it wants to do that when you pull back that hard, just dont pull back like that, right? I just wondered if anyone else has encountered this, and has anyone had the peice of foam that is held on by magnets above the motor and edf fly off yet? Today as I was really picking up some good speed that thing just blasted off!
And those servo protectors under the wings are not very useful, they keep breaking off when I land.
#140
Senior Member
Join Date: Feb 2008
Location: st. louis,
MO
Posts: 156
Likes: 0
Received 0 Likes
on
0 Posts
RE: Great Planes L-39
So tonight I used my wing tanks as skids on the belly and glued them on, right next to the srvos in hopes that they will act as protection for these servo horns that stick out the bottom, and if that doesnt work I have thought about routing everything on the top of the wing, just put a small hole in the wing for the horn top fit through and flip the aileron hing upside down also, but I think it would require a longer horn, any thoughts on that? and does anyone know how fast this thing is going with a wicked extreme 54ookv on 3cell 2200mah 25C?
#141
Member
Join Date: Mar 2008
Location: Ft. Lauderdale, FL
Posts: 64
Likes: 0
Received 0 Likes
on
0 Posts
RE: Great Planes L-39
I think I have said this a few times.
Solution: Purchase S3156 MG servos. Your servos will never break again and you will be able to land on the belly in normal configuration.
[link]http://www3.towerhobbies.com/cgi-bin/wti0001p?&P=PR&I=FUTM0656[/link]
Solution: Purchase S3156 MG servos. Your servos will never break again and you will be able to land on the belly in normal configuration.
[link]http://www3.towerhobbies.com/cgi-bin/wti0001p?&P=PR&I=FUTM0656[/link]
#142
RE: Great Planes L-39
I have not broken a servo yet and I have no servo arm covers and I am flying a 4S 2250 lipo as well. You will like the stock fan on 3S with the Extreme, just make sure you have no wobble from the spinner. I dropped about 3 amps on mine after I balanced the spinner. I also added an exit nozzle tube to get the 80% outlet area.
Don
Don
#143
Senior Member
Join Date: Feb 2008
Location: st. louis,
MO
Posts: 156
Likes: 0
Received 0 Likes
on
0 Posts
RE: Great Planes L-39
Glad to hear that your servos are not getting chewed up, the skids work great though, and I am using a XF fan instead of the hyperflow. Can you tell me about the exit nozzle tube, you said 80% what is the diameter of the exhaust? and can you show it on this thread?
#144
RE: Great Planes L-39
My servos and my buddie's servos stripped. It seems that they all will sooner or later.
We upgraded the motor to a 4200kv and they fly very well. plenty of flight time. Actually we have built four now after destroying the first two when we tied the record for the lowest high speed pass
Here are some tips/changes that I would like to pass along for anyone who might find them usefull.
1. put the servo arms through teh top of the wing and put the horns on the top. You will get zero gears stripping.
2. Consider using 1/16" up-aileron on both sides for hand launch and landings. Lets the airplane fly much slower without tip stalling. Very stable on launch. Gives you lots of time to get your hand back to the sticks.
3. Move elevator servo back under stab. Helps with CG when using big Lipo packs (2200 mAh 3 or 4 cell etc.) There is now no servo in the rear of the cockpit
4. Add a rudder servo into fin. Really needed for formation flying and smooth course corrections at speed etc. Does the same as #3
5. Cool off the battery with ducts. Mine used to get very hot. Now they are easy to handle and I am much happier knowing that I am much less likely to fry a pack in the air.
Regards,
Eric.
Below are some easy high-vis. mods. The LED shows up well in teh truns towards you and also tells you that you have left your pack plugged in!
We upgraded the motor to a 4200kv and they fly very well. plenty of flight time. Actually we have built four now after destroying the first two when we tied the record for the lowest high speed pass
Here are some tips/changes that I would like to pass along for anyone who might find them usefull.
1. put the servo arms through teh top of the wing and put the horns on the top. You will get zero gears stripping.
2. Consider using 1/16" up-aileron on both sides for hand launch and landings. Lets the airplane fly much slower without tip stalling. Very stable on launch. Gives you lots of time to get your hand back to the sticks.
3. Move elevator servo back under stab. Helps with CG when using big Lipo packs (2200 mAh 3 or 4 cell etc.) There is now no servo in the rear of the cockpit
4. Add a rudder servo into fin. Really needed for formation flying and smooth course corrections at speed etc. Does the same as #3
5. Cool off the battery with ducts. Mine used to get very hot. Now they are easy to handle and I am much happier knowing that I am much less likely to fry a pack in the air.
Regards,
Eric.
Below are some easy high-vis. mods. The LED shows up well in teh truns towards you and also tells you that you have left your pack plugged in!
#146
RE: Great Planes L-39
A 3/8 balsa paltform was added in the bootom of the cockpit. It raised the pack and stopped the floor breaking up when pack was pulled away from the Velcro.
#148
Join Date: Apr 2006
Location: Dickinson,
ND
Posts: 813
Likes: 0
Received 0 Likes
on
0 Posts
RE: Great Planes L-39
Eric you have some great mods there I will be doing some on my next plane, which should be soon. Has anyone done any paint jobs one this plane yet if so post some pics please. I have crashed mine three times because of the same reason a tight turn which causes a stall then I can't tell which way is up and crash. So I either have to stop flying at evening (all three were also in the evening) or paint it nice bright colors so I don't lose it in evening light.
Last thing for now I am planing on going with this setup for my next one....
http://www3.towerhobbies.com/cgi-bin...&I=LXLWX8&P=ML
Which will give it this power...
Optional Brushless Motor 24-45-3790
2 7.4V 9.7A 72W 207g (7.3oz) 27,120 27.95 62.51
3 11.1V 19.9A 221W 450g (15.9oz) 38,600 60.75 135.89~
4 14.8V 32.6A 482W 721g (25.4oz) 48,000 97.34 217.73~.... Thats 25.4 oz of thrust it should go vertical with that much thrust LOL I hope
Then the S3156 Futaba servos....
http://www3.towerhobbies.com/cgi-bin...&I=LXSWC4&P=ML
With these 4 cell Flight Power Lipo's but i will still use my current 3 cells also...
http://www3.towerhobbies.com/cgi-bin...?&I=LXRVY7&P=7
And of coarse use my current 35amp Castle Creations ESC with the Castle BEC....
http://www3.towerhobbies.com/cgi-bin...?&I=LXGVS1&P=7
http://www3.towerhobbies.com/cgi-bin...?&I=LXSWL3&P=7
I am thinking about painting the plane Black with yellow "racing" stripes and underside of wings. What do you think???
Last thing for now I am planing on going with this setup for my next one....
http://www3.towerhobbies.com/cgi-bin...&I=LXLWX8&P=ML
Which will give it this power...
Optional Brushless Motor 24-45-3790
2 7.4V 9.7A 72W 207g (7.3oz) 27,120 27.95 62.51
3 11.1V 19.9A 221W 450g (15.9oz) 38,600 60.75 135.89~
4 14.8V 32.6A 482W 721g (25.4oz) 48,000 97.34 217.73~.... Thats 25.4 oz of thrust it should go vertical with that much thrust LOL I hope
Then the S3156 Futaba servos....
http://www3.towerhobbies.com/cgi-bin...&I=LXSWC4&P=ML
With these 4 cell Flight Power Lipo's but i will still use my current 3 cells also...
http://www3.towerhobbies.com/cgi-bin...?&I=LXRVY7&P=7
And of coarse use my current 35amp Castle Creations ESC with the Castle BEC....
http://www3.towerhobbies.com/cgi-bin...?&I=LXGVS1&P=7
http://www3.towerhobbies.com/cgi-bin...?&I=LXSWL3&P=7
I am thinking about painting the plane Black with yellow "racing" stripes and underside of wings. What do you think???
#149
My Feedback: (15)
RE: Great Planes L-39
sweet mods! mines at 24oz. with a 4s-2200,gws motor,xf-fan,spin75 opto,medusa bec and hs-65's for servos,i moved the ele. servo up forward in the nose and hogged out some foam for the batt to acheive cog,also i put some cf strips on the horiz. to stiffen and did a high visibility paint scheme,i'm pulling roughly about 34amps and puttin out 400+watts,sweet flyer