EDF ARF SU-27 Flanker Built

[ER69]

After I had scrapped my Mirage 2000 couple of weeks ago,
I decided to built another EDF Jet about its size by twice the power.
one day, I visited a LHS and this ARF SU-27 really caught my attention so I decided to make it my next project, no doubt i still have a on going project in hand. :D

This jet is actually designed as a pusher but i will convert it into ducted with landing gears.

Ok here are the specs of this SU 27

wing Span :670mm
Length : 900mm
Flying weight : 530 (Pusher) recon
: about 1kg (Ducted)
DF : 2 x SF DF units
Motor :2 x Rcer Warp4 2turn
ESC : 2 x CC45
Batt : 3s2p1800 (20c)
Amp draw : 38A +-

[ER69]

To have a smooth and clean fuse / duct, I decided to glass the whole kit with resin and 3/4oz glass cloth.
End of the day, it will add some weight. :z :D

[ER69]

EDF units

[ER69]

The exisiting control system design of this EDF jets is by using only tailerons and its control by 2 servos pulling from the wings with carbon rods.
Well, I think it makes this so called "scale" Jet looks ugly.
So I decided to do some modification to it, to make it looks more "scale" looking, by adding ailerons for the wings and make the tailerons into elevator.
First, I covered the exisiting servos support holes with foam filler and make 2 new one for it.
That mean i will be using 2x HS55 for ailerons and 1x HS56 for tail.

[zennith]

Dear ER69
I am Zennith, I bought the Su27 when I first saw in the shop. After sanding the whole body, I found that the elevator got a fifty cents coins size indent form by the molding process. Tyring hard to cover that by depron but bad looking. How do you reduce the uglyness? I also found that the I got a power system problem - Batteries to power her Poliy questx2 at the nose compartment C.G. moves. Also the mounting for the fan is rather weak very little holding on her body (the half cut on the top and bottom body only give me partial holding- problem.... I hold back the building.
When are you doing a median flight, do allowed me to join you for the flight.
Help is required from expert for the building...
Zennith

How is your EDF A10? flew...

[ER69]

I like to R.O.G. planes.
For me, the most enjoyable part of RC flying is by watching the plane taking off and landing :love
Therefore, How can i build this EDF jet without landing gears. :D

I had relocated the forward nose gear by swifting it more to the aft, coz i think the existing position on the it is way too forward.

I asked one of my flying Kaki about the location to fix the main gear, His suggestion is that to place it somewhere in the middle of the bottom Fuselage.
At first, I was thinking about putting it at the C.G. point or slightly backward. :z
but he told me that It might hit the afterbuner when taking off or landing.

[HZM]

Looking good :up

Mike

[Adrianli]

Nice work!!

When maiden? Must post hor. :D

[Warbird]

Jup, nice work !!
I agree landing and take-off are the most interesting parts of flying.
Good, light and small retracts is what the world is waiting for. Until then I will use bungee :D !!

[ER69]

Nice work!!

When maiden? Must post hor. :D

Maiden i guess will be next weekend if things are going smoothly :D
Coz I only can squeeze out 1-2 hrs of building time every nite :(

[ER69]

Jup, nice work !!
I agree landing and take-off are the most interesting parts of flying.
Good, light and small retracts is what the world is waiting for. Until then I will use bungee :D !!


:L Yup, hopefully some day, retracts makers can come out some small & light air retracts which can hold Jets of this size.
Or shall we go for bigger size EDF Jets so we no need to wait for that small retracts?.. :D

[ER69]

Dear ER69
I am Zennith, I bought the Su27 when I first saw in the shop. After sanding the whole body, I found that the elevator got a fifty cents coins size indent form by the molding process. Tyring hard to cover that by depron but bad looking. How do you reduce the uglyness? I also found that the I got a power system problem - Batteries to power her Poliy questx2 at the nose compartment C.G. moves. Also the mounting for the fan is rather weak very little holding on her body (the half cut on the top and bottom body only give me partial holding- problem.... I hold back the building.
When are you doing a median flight, do allowed me to join you for the flight.
Help is required from expert for the building...
Zennith

How is your EDF A10? flew...

Hi Zennith,
Regards the Injection mold mark, wat you can do is, use grade 180-220 sand paper to sand it till level, then fill up with foam fillers (which can purchase from NTC) , after filler completely dried up, sand again, Thats it.

As for the batts compartment, I had cutted out the bulkhead inside the turtle neck and strengthen it with balsa at the bottom, by doing this, I will have more room to play around with when placing those batts to meet the C.G.

Wat I did to support my DF unit is that, I cutted out some 3mm depron to lay and epoxy them over the Support at the exsiting duct (Top & Bottom).in order to make it level with the ducting. Then i cutted slot on the DF support area to hold the DF unit "ears" ( Check check out those pics that i had posted for better idea)

[ER69]

I had modified the tailerons into elevators which will be pulling by a HS 56 servo. here are some pictures of the mod.

[ER69]

Yesterday, I received an SMS from my friend who had the same landing gear and kit as mine.
He did a test on R.O.G, claim that the landing gears are infact very weak. :z
He told me that the wheel shaft had infact "Melted" (guess is due to fiction). Weak materials . :down
Since i am still building this Jet at the moment, I decided to replace the nose gear wheel's shaft with metal rod. No doubt it will add some weight, but better than having a melted gear when landing ya :L

[ER69]

Hi Zennith,
Notice that you had encountered some problem when building this SU.
Hey, perhaps you can post some picture of it, I think other flyers had built this can also guide you along, worry no more, all problem can be solved, once started dont stop half way. :D
Anyway, that is the problem wth those "Clone" kit,
It normally comes with a very simple building instructions and most of the time with wrong C.G. point stated. :down
Thats why Frank is having his worst time getting the C.G right. :z
and Thats also the reason why i started this building tread. :D
May the force be with us.. :up

[AsiaSRC]

Hi Er69,

Nice little corner you have now 4 edf.

As always, you never fail to bring new edf building thread, su27 just another good one. :up

Another building su27 in progress, that i'm also watching closely is harald's beast! another bull one . :D

[AsiaSRC]

first kit has already roll out, btw he told me that this plane wouldnt be available for SALES, no even one and strictly for his collection.

[ER69]

Hi AsicSRC,
Infact I had been keeping track on this guy's site.. I really admire his building skill.. :love :up
I bet you will see a building thread of depron EDF jet about this size coming soon in this forum...So stay tuned.. :L :sneaky:

[ER69]

Hi guys,
My friend had finished building this SU 27 and maiden it today at tuas.
Here is some of the findings of this kit and landing gear.

1. C.G point stated, out :down
2. Landing gear position stated in instruction manual, out :down
3. Those landing gears cant even hold the weight of the plane (Broke) when landing (he did even glass the plane) see pic attached. :down

We tried to R.O.G. this baby but no matter how we tried, it just dont wan to take off.. so we decided to hand lanuch it, first try, took off but C.G out.
When he landed it guess wat, landing gear broke (weak materials used)
anyway, We took out those landing gears, changed the C.G. and hand launch it. On second attempt, flew very well with just a few clicks on the trim.

After the maiden, it really make me think twice to try out those landing gears on mine, as my plane will weight around 1kg (glassed).
I think i will use other gear instead. :z :D

Anyway, Here are some video clips of the maiden.

Take off - http://www.daddyhobby.com/gallery/showphoto.php?photo=758&cat=500&ppuser=652

Fly pass- http://www.daddyhobby.com/gallery/showphoto.php?photo=759&cat=500&ppuser=652

[ER69]

After my friend's maiden on this SU27 last weekend, I decided to reposition the main landing gear closer to the C.G point rather than the position stated in the instruction manual.
Well, Instead of using back those "weak" landing gear for this kit, I had made my own out of some steel rod.

[ER69]

Here are some updates on the landing gear and tailerons.
Tonite, I will work on the DF units :D

[Frank]

nice :up

[ER69]

Managed to sit in the DF units, servo in place.
As for now, i am still waiting for one more CC45 ESC to arrive at my door step, should be anytime this week. :D

[ER69]

I had cutted away those bulkhead to make room for the batts, as i will be using 3s2p1800, To strenghten it, I added some balsa at the bottom of the turtle neck.

[ER69]

Here comes the wings part, I had added some carbon rods to support those wings.

[ER69]

Looks more like a Jet now ya.. :D
Well,got to stop at this stage, as i just relised that i ran out of finishing resin to glass the top of those wings and cockpit cover,
Will get it tommorow and resume to build. :furious :D

[Blackite207]

Dear ER69,
I think I know why the plane refused to take off during the run.
The intake ducts are too close to the ground and causes a "suction" low pressure area under the belly of the plane. You have 2 ways to correct this. 1) have a longer landing gear and 2) build in a higher angle of attack by increasing the length of the front gear.
If it happens again, at high speed, cut the trottles, pull full up and be prepaired to release back pressure on the sticks and hit the trottle again once airborne.
Good luck on the next flight. The Flanker is looking good!
Cheers!

[ER69]

Dear ER69,
I think I know why the plane refused to take off during the run.
The intake ducts are too close to the ground and causes a "suction" low pressure area under the belly of the plane. You have 2 ways to correct this. 1) have a longer landing gear and 2) build in a higher angle of attack by increasing the length of the front gear.
If it happens again, at high speed, cut the trottles, pull full up and be prepaired to release back pressure on the sticks and hit the trottle again once airborne.
Good luck on the next flight. The Flanker is looking good!
Cheers!

Hi Blackite207,
You are right, That's one of the reason why my friend's SU just refused to R.O.G.
Another thing is that he had placed the main gear too far from the C.G. point Thats why cant take off.
Anyway, I had re-located the main gear closer to the C.G and also make them slightly longer.
I didnt increase the angle of attack coz i wan it to looks more scale looking. :D
Hope R.O.G will works on mine.. :z
Thanks for your advice, I really appreciated it. :up :up
The reason why i post all my building thread coz i need Flyers like you to correct and advise me on any mistake which i had made during the building process.
Once again, Thanks a lot :up

[Blackite207]

No problem Bro.
I was a pilot once upon a time.
I made an su27 out of depron from Green Air Designs. Flew great but was very fast. Burned the speed 400 on the 5th flight coz I ran the 6v sucker on 11.2 3S lipos. Was a good test bed for my next project. Building a 150% F5 (glory days) found on the free plans page
http://www.parkjets.com/free-plans.html.
They also have EDF planes that look really cool. Check it out if you have not already done so.
Good luck on your next flight.
Cheers!

[ER69]

No problem Bro.
I was a pilot once upon a time.
I made an su27 out of depron from Green Air Designs. Flew great but was very fast. Burned the speed 400 on the 5th flight coz I ran the 6v sucker on 11.2 3S lipos. Was a good test bed for my next project. Building a 150% F5 (glory days) found on the free plans page
http://www.parkjets.com/free-plans.html.
They also have EDF planes that look really cool. Check it out if you have not already done so.
Good luck on your next flight.
Cheers!

Cool.. :up
All the best Bro.

[ER69]

Ok.. Looks like this little project of mine is coming to the end soon.

I had finished the modification of the ailerons on the wings.
Outstanding items to be completed are :
1. ESC & RX to be installed
2. Servos for wings to be installed
3. Pilot for the cockpit.

Thats it, I think I will spray this baby after my maiden. :D
As for now, still not sure wat colour to put on it. :confuse:

[ER69]

Guys,
Which colour scheme do you guys think will look nice on it?
Or do you guys have some better colour scheme?
BTW, I think this "Su" that i am building looks more like Mig29 instead. :L

[ggoh76]

Dun think so if you put in the missiles..... :evil

Guys,
Which colour scheme do you guys think will look nice on it?
Or do you guys have some better colour scheme?
BTW, I think this "Su" that i am building looks more like Mig29 instead. :L

[AsiaSRC]

Hi AsicSRC,
Infact I had been keeping track on this guy's site.. I really admire his building skill.. :love :up
I bet you will see a building thread of depron EDF jet about this size coming soon in this forum...So stay tuned.. :L :sneaky:

time and extra $ are the main ingredient, other can easily pickup.

[ER69]

I had installed the ESCs and run the cables.
To have a better air flow inside the duct, I had placed the ESCs forward and digged well for them to sit in, same goes for the servos cables.
After that I covered it with fiber type and sprayed some paint over .

[ER69]

This is how my SU looks like at the moment.
Cables need to be tidy up and that is how my batts are going to sit in the fuse.
Total weight of this little EDF jet is 1120g (without paint yet)
I bet this going to fast man..... :z

[Frank]

Very nicely done :up
Can you build one for me also :D

[ER69]

At last.. the building of this Su ..err.. or Mig is coming to an end. :D
The building time is a bit long for an ARF coz lots of time was wasted on the glassing and lots of sanding job to be done.
Well, at least it's over and i can concentrate on my next "Big" F15 project.
I had tested the set up of tghis EDF Jet and did some adjustment accordingly.

Amp draw : 43A
Watt produces : 950watts by 2 DF units.
Total weight : 1250g (nose heavy, added 42g of deadweight at Aft :down )

Now, everythings are in place, will push it into spray shop for some paint job within this 2 days and hopefully can maiden by this weekend if my maiden team members can make it. :D

Cheers :up

[Frank]

Where is the maiden :confuse:

[ER69]

Where is the maiden :confuse:

Yo Frank

Maybe this Sunday, coz sat might need to go back camp (Recall) :rolleyes:
BTW, Can i trust the C.G. piont stated in the manual?
It seems very much nose heavy.. :z :D

[Frank]

Yo Frank

Maybe this Sunday, coz sat might need to go back camp (Recall) :rolleyes:
BTW, Can i trust the C.G. piont stated in the manual?
It seems very much nose heavy.. :z :D

Where will it be :confuse:
It will be better if its nose heavy but not too much. :z
I tested mine with CG in between the curved recess and the edge of servo well

[HZM]

Where will it be :confuse:
It will be better if its nose heavy but not too much. :z
I tested mine with CG in between the curved recess and the edge of servo well


:z :z :z

Let us know please :confuse:

Mike

[ER69]

I think it will be at woodlands or tuas coz i need a runway for R.O.G.
I guess mostly will be at woodlands on Sunday around 3~4pm as
Saturday I have to standby for recall .. :D :confuse:

[ER69]

Finally, I had decided on the Russian Aerobatic team -Swift colour scheme for my Su & Mig look alike EDF jet. :D
I will continue the paint job tonite and hopefully it will be out of the oven by Friday. :L

[ER69]

Fresh from the oven.. :D

[Frank]

Very nice :up
Is it airbrush? :S
What kind of paint you use :confuse:

[ER69]

Very nice :up
Is it airbrush? :S
What kind of paint you use :confuse:

Oh thanks Frank... :D
Yes its airbrush.. I used those water base colours in small bottles selling at Artfriends, Sorry, just cant recall their brand at the moment. will let you know soon. :)

[ER69]

Some more view from the bottom :D

[Frank]

Oh thanks Frank... :D
Yes its airbrush.. I used those water base colours in small bottles selling at Artfriends, Sorry, just cant recall their brand at the moment. will let you know soon. :)

Thanks for the info :up
I know of this particular brand folkart which is acrylic type

[kennyc]

Some more view from the bottom :D :up :up :up :up when maiden?

[ER69]

I got to thanks all my friends who attended my Maiden today at woodlands.. :up
No doubt, It was an unsuccessful one but I am really glad to have all the support from you guys..
I had learned from Jeff's and Frank's previous maiden results and i had corrected them when building this EDF jet as follows,
1. Forward the C.G. point (as the C.G. stated in the manual for DF version is totally out .)
2. Brought forward the position of the main gear closer to the C.G. and increase the angle of attack.
When It was going at it full speed during R.O.G., for more than 100 m, it just refused to take off.. :D
After 3 tries, decided to hand luanch it, 1st tried failed, 2nd tried, went up but one motor suddenely cut and it went totally out of control.
End of the day, we realised that its due to one of the dean connection which came loose, therefore, that was only one batt to power those fans and due to the insufficient of current supply, one of the ESC cutted.
My friend had pointed out to me some of the design fault of this kit and it will be better to fly it as a pusher rather than Df, as pusher is more forgiving in term of flying.
This really makes me wonder that is this kit still at proto type stage? coz It does have quite a bit of things to be improved on it. (my point of view)
Anyway, It will make a nice display kit on hanger. :rolleyes:
Well, here are some pics taken today.. :L

[ER69]

.....
Will post some clips and you guys will know how fast it was going... :D
It just refused to take off.. :z

[Demented]

sad to see such a beautiful bird not been able to fly... any plans to improve/correct all the problems? when remaiden? i wanna see...

[Ryan]

for you.

[Ryan]

:)

[ER69]

sad to see such a beautiful bird not been able to fly... any plans to improve/correct all the problems? when remaiden? i wanna see...

Hi Demented,
Well, I am afraid that you wont be able to see it anymore coz i had discommission it on the spot after it failed to perform as i dun wish to spend more time on it . All in pcs now... :D
Well, I had did all the corrections, calculations and necessary improvement on it and it still fail on me.. :bigcry
Anyway, Dun worry, you will see a more scale and much much much bigger EDF jet in the air soon.. :L

[ER69]

for you.


Haha.. Thanks Ryan..
At least i got a few seconds of air time ya.. :D
Well guys, Last few pics are when starboard engine being cutted ..
Luckily its got no pilot in it.. :L .. :up

[freeman]

Hi,

I am freeman, newbie in this forum and flying R/C. Got myself a SU 27 and was wondering which control to chose from. Conventional elevator and aileron or tail -ailervon, mixding of elevator and aileron on the stab control surfaces...

From the previous posting, it seems that the pusher version is better for this kit. Any comment on that?

Thanks..

Cheers :lip:

[Frank]

Hi Demented,
Well, I am afraid that you wont be able to see it anymore coz i had discommission it on the spot after it failed to perform as i dun wish to spend more time on it . All in pcs now... :D
Well, I had did all the corrections, calculations and necessary improvement on it and it still fail on me.. :bigcry
Anyway, Dun worry, you will see a more scale and much much much bigger EDF jet in the air soon.. :L

Very nice :up
Too bad didn't fly well :(
I'm going to scrap mine also, not a nice flyer :furious

[ER69]

Very nice :up
Too bad didn't fly well :(
I'm going to scrap mine also, not a nice flyer :furious

Haha.. it "flew" for a few seconds.. :D
I had already scrapped it into small little pcs right after the maiden..
Btw, I had seen a video clip with a pusher on it which flew pretty well..
but pusher on a Jet ? ? na.. think we will pass... :lip:

[ER69]

Hi,

I am freeman, newbie in this forum and flying R/C. Got myself a SU 27 and was wondering which control to chose from. Conventional elevator and aileron or tail -ailervon, mixding of elevator and aileron on the stab control surfaces...

From the previous posting, it seems that the pusher version is better for this kit. Any comment on that?

Thanks..

Cheers :lip:

Hi Freeman,
Well, end of the day its really up to you to choose which type of control to be used on this SU. coz I might feel comfortable with the control that i had used on this kit but you might not.. so inorder to save time and trouble to do the mod, i would recon that you go for the factory set up.
Anyway, It's easier to fly with conventional elevator and aileron.
As for this kit, I think pusher will be more forgiving in term of flying.
if you like R.O.G like i do, make sure you have a real long main gear so that it wouldnt hit the prop when taking off and a real long nose steering gear to have a better angle of attack for taking off ...
Have fun and enjoy building it.... :up

[ER69]

At last , found a free video files converter download to convert from Avi to mepg format. :D :z
link to R.O.G and taxi video ...
Check out the link. http://www.daddyhobby.com/gallery/showgallery.php?cat=500&ppuser=652&sl=e

[kennyc]

At last , found a free video files converter download to convert from Avi to mepg format. :D :z
link to R.O.G and taxi video ...
Check out the link. http://www.daddyhobby.com/gallery/showgallery.php?cat=500&ppuser=652&sl=e
use widows movie maker to convert to WMV its free and you already have it and it does not have the irritating "trial version"

[ER69]

use widows movie maker to convert to WMV its free and you already have it and it does not have the irritating "trial version"

Thanks Kennyc..
ok check out the taxi clips after the convertion without those watermark wordings... :D
http://www.daddyhobby.com/gallery/showphoto.php?photo=914&cat=500&ppuser=652

[freeman]

sad to see such a beautiful bird not been able to fly... any plans to improve/correct all the problems? when remaiden? i wanna see...

Regarding unable to t/o despite high spped run. One of the reason that I can think of is the placement of the main landing gear. A guide for main landing placement is 6 deg aft of the CoG. Which means from the CoG, draw a line 6 deg aft and the tangent between the ground and the wheel have to cut the 6 deg line. Hope it is not too complicated. Try that and it may just solve the rotation problem.

Cheers. :up

[ER69]

Regarding unable to t/o despite high spped run. One of the reason that I can think of is the placement of the main landing gear. A guide for main landing placement is 6 deg aft of the CoG. Which means from the CoG, draw a line 6 deg aft and the tangent between the ground and the wheel have to cut the 6 deg line. Hope it is not too complicated. Try that and it may just solve the rotation problem.

Cheers. :up

Hi Freeman,
Thanks for pointing out this... :up
Infact I had corrcted the position of the landing gears. (The original position stated in the instruction manual will make you faint) :z
Another factor that might cause this could be, coz the bottom fuse is too close to the ground which created a suction to it...
Since I had swifted the main gear closer to the cg, increased the angle of attack and the power is there, By right is shouldnt be a problem for R.O.G...
By left.. :bigcry :D

[X34]

From the ROG video it looks like it had lots of speed should be enuf to take-off.

U might be experiencing the same problem I had many yonks ago with glo ducted fan plane with cheater hole. The plane screams down the runway and it wouldn't take-off. On one attempt, mid way along the take off try, I decided to abort by reducing the throttle stick and the plane jumps into the air without elevator input.

Hope this helps to explain why it didn't take-off.

[ER69]

From the ROG video it looks like it had lots of speed should be enuf to take-off.

U might be experiencing the same problem I had many yonks ago with glo ducted fan plane with cheater hole. The plane screams down the runway and it wouldn't take-off. On one attempt, mid way along the take off try, I decided to abort by reducing the throttle stick and the plane jumps into the air without elevator input.

Hope this helps to explain why it didn't take-off.

Thanks..
I will keep it mind when it happens to me again..
Once it starts to gain speed and refuse to take off, I will cut the throttle abit, elev up and power up again.. :D
Thanks a lot..

[Babylon5]

:love Hi , I should post my query here.
I am building this plane and intend to use a single EDF unit for simplicity and to keep the weight down to less than 750gms.
May I know the correct c.g and and other major modification in order to sucessfully R.o.g and fly this plane. Points on full power, then cut prior to take off as suggested will be taken into consideration.

Since I have seen quite a few sucessful flight with this kit. Appreciate if you can share your success of the SU27

Thank you for all the tips. :up


Have a pleasant day

Babylon5

[Vortices]

Dear ER69,
great effort. Could hear the frust in your voice. May not know how it works but definately now know how it would not work.

I am in a similar state of dillema...with my Lear 45! very similar actually, glassed the fuselage and all up weight is 1080gm, 15.5 oz/sq ft. Has strip flaperon with a 3 degress wash out. :z

Got so fed up with it as it is taking so much time. I think I have fill sand paint seal then fill sand paint seal 5 times already! got so bored went and built a formosa just to vent! :fire:

Now it is looking back at me, so I guess its time to work on it again.

Looking at you su-27, fail to ROG take off is always because of one reason, be it a 4 engine bomber, propeller or jet, as a matter of fact I know of a few real planes that had same problem during maiden. It the main gear being too far back compounded with a short nose gear giving negative angle of attack on grd.

I have come across a rule that has work for me all this years, Put your plane on flat surface. Draw an imaginary line straight down from the CG. then draw another line from the cg but sweep 6 degrees back from the first line.. the point where the second line meet the grd is where the main tire should touch the grd, the gear strut cant be mounted anywhere and of any shape.

Secondly, nose gear and main gear should let the main wing sit no more than -3 degres. On fast props plane this is good as it stops the wing from producing any positive lift after nose gear touches the grd. However for delta and symetrical aerofoil, 0 to -1 degree would be optimum.

Being all theory is sometime a joke, so after you have set up everything with batts in and ready to go, put the plane on a flat surface and using one finger press down on the elevator to try lift the nose. It should be very-very light. If it requires enough pressure for you to feel that your finger tips are flaten in the process, maingear too far back (assuming CG is correct.)

Hope you still have the plane. Its so pretty that it is nice enough to be your workshop guardian :up

I know its probably water under the bridge, but hopefully others will benefit from it. Hope to meet you one day and perhaps share a group built...interested in red arrow hawk-turbine?!! :up :love

[ER69]

Hi Vortices,
Thanks for the advice,I will keep them in mind, and use it when ever I need to install landing gears in future, :up

Hey, I like the lear 45 which you are building at the moment, really cool :love
Hope to it in the air soon..Cool..

As for my SU, I had scrapped it right after the maiden coz I need those electronics for my other EDF jet and dont really wish to spend more time on it :D

Well, I would say that in Singapore there is only a small group of hardcore EDF flyers who I know are into scale EDF jet, therefore I am really looking forward to meet up with you guys or perhaps we can have an EDF jets meet one day. :D

Btw, I just got myself a AMD hawk couple of weeks ago and now I am waiting for my friend to bring back a suitable "Sucker" for it, before I start building it.
Anyway, Do you have one as well?

Dear ER69,
great effort. Could hear the frust in your voice. May not know how it works but definately now know how it would not work.

I am in a similar state of dillema...with my Lear 45! very similar actually, glassed the fuselage and all up weight is 1080gm, 15.5 oz/sq ft. Has strip flaperon with a 3 degress wash out. :z

Got so fed up with it as it is taking so much time. I think I have fill sand paint seal then fill sand paint seal 5 times already! got so bored went and built a formosa just to vent! :fire:

Now it is looking back at me, so I guess its time to work on it again.

Looking at you su-27, fail to ROG take off is always because of one reason, be it a 4 engine bomber, propeller or jet, as a matter of fact I know of a few real planes that had same problem during maiden. It the main gear being too far back compounded with a short nose gear giving negative angle of attack on grd.

I have come across a rule that has work for me all this years, Put your plane on flat surface. Draw an imaginary line straight down from the CG. then draw another line from the cg but sweep 6 degrees back from the first line.. the point where the second line meet the grd is where the main tire should touch the grd, the gear strut cant be mounted anywhere and of any shape.

Secondly, nose gear and main gear should let the main wing sit no more than -3 degres. On fast props plane this is good as it stops the wing from producing any positive lift after nose gear touches the grd. However for delta and symetrical aerofoil, 0 to -1 degree would be optimum.

Being all theory is sometime a joke, so after you have set up everything with batts in and ready to go, put the plane on a flat surface and using one finger press down on the elevator to try lift the nose. It should be very-very light. If it requires enough pressure for you to feel that your finger tips are flaten in the process, maingear too far back (assuming CG is correct.)

Hope you still have the plane. Its so pretty that it is nice enough to be your workshop guardian :up

I know its probably water under the bridge, but hopefully others will benefit from it. Hope to meet you one day and perhaps share a group built...interested in red arrow hawk-turbine?!! :up :love

[Vortices]

not yet thought of it though..bright red arrow livery would be cool...even cooler if there are two then can do aerobatics and small air show!! :hammer

Are you thinking of wemotec 480? it going to be heavy again! I am quite sure.
Where is the hawk available in Sin? might just get one, bonus coming! :sneaky:

I will tell you when I will maiden my lear when its ready may be you can come and help me out. It will be at woodlands. Probably apr 30th.

see you. Take care and God Bless.

[ER69]

not yet thought of it though..bright red arrow livery would be cool...even cooler if there are two then can do aerobatics and small air show!! :hammer

Are you thinking of wemotec 480? it going to be heavy again! I am quite sure.
Where is the hawk available in Sin? might just get one, bonus coming! :sneaky:

I will tell you when I will maiden my lear when its ready may be you can come and help me out. It will be at woodlands. Probably apr 30th.

see you. Take care and God Bless.

Hi Vortics,

Sorry, I thought that you are talking about the other hawk.. :hammer :L
As for my hawk, I dont think wemo mini or midi fan can do the job.
Well, I will be going for other type of power instead of EDF. :D

BTW, do let us know when you are going to maiden your lear .. :up

[Vortices]

Very nice. You mean you are going to put a turbine in it! :freak: ??

well that would be great! I will be there for the maiden :hammer

I dont have one, I will get comfortable with edf jet then throttle delay edf before moving on to turbines, I think it is the safest way to do it from propellers.

yah, will let you know of the lear maiden. cheers!
by the way I am certified jet engine engineer for real airplanes, would be really interested to see how the miniature jet works :freak:

[DennisP]

Hi ER69, good to see pictures of your Hawk.., mine is still in the box too much work on and too many projects at the moment. Just a point about fitting a sucker in the Hawk please beware it is not designed for suckers, AMD have now released a sucker version and there are a few differences in the tail end (check the web site). Not sure if you have read the destructions (sure that you have) but the all flying stabilser torque rod goes right through the jet pipe...! so some serious engineering is required here. Of course I am sure that you are capable of doing same and would be interested to hear of the modification that you perform. Also on the AMD web site is a video of the 46 size ICDF version in fright, long take off but once airbourne boy does she boogie... :up

[ER69]

by the way I am certified jet engine engineer for real airplanes, would be really interested to see how the miniature jet works :freak:

Cool :up next time you can do the pre-flight check for me then... :D :L

[ER69]

Hi ER69, good to see pictures of your Hawk.., mine is still in the box too much work on and too many projects at the moment. Just a point about fitting a sucker in the Hawk please beware it is not designed for suckers, AMD have now released a sucker version and there are a few differences in the tail end (check the web site). Not sure if you have read the destructions (sure that you have) but the all flying stabilser torque rod goes right through the jet pipe...! so some serious engineering is required here. Of course I am sure that you are capable of doing same and would be interested to hear of the modification that you perform. Also on the AMD web site is a video of the 46 size ICDF version in fright, long take off but once airbourne boy does she boogie... :up

Yo Dennis,

WAT? yours is still in BOX? :hammer :L

Yup, I am aware of the AMD sucker version hawk, :(
Well, guess we have to do lots of re-enforcement on our airframe/wings and some heat proofing job as well before throwing a sucker into it..
OMG, there will be lots of work to be done mann..... :z
Anyway, I will see how it goes then.. :confuse: :( :D

Cheers mate















I had read about it

[DennisP]

Hi ER69 perhaps we should start a new thread rather than hi-jacking this one..? I was going to send a mail to AMD and ask if they could provide a conversion kit..? The other option is to wait until they put the manual on line for the sucker version then the secret will be out... :up

[ER69]

Hi ER69 perhaps we should start a new thread rather than hi-jacking this one..? I was going to send a mail to AMD and ask if they could provide a conversion kit..? The other option is to wait until they put the manual on line for the sucker version then the secret will be out... :up

Yeah .. that will be great.. :D
Yo Dennis, you are the man.. :up

[madflurry]

hi there

i'm new to EDF jet and i thought of getting the SU27 for my first. Just wanted to ask a few questions about this jet. Is conventional brush motor enough to power this jet? or do you need brushless to do the job? and is there any other nice to fly jets out there to recommend? thank you!

[Babylon5]

hi there

i'm new to EDF jet and i thought of getting the SU27 for my first. Just wanted to ask a few questions about this jet. Is conventional brush motor enough to power this jet? or do you need brushless to do the job? and is there any other nice to fly jets out there to recommend? thank you!

Hi madflurry, if you check Er69 and others on the SU27. This plane is definitely not a good candidate for new EDF experiment.
You should try the DF10 interceptor available at JH or champion H.
Easy to hand launch and can be flown with just 21-23 amps on 3 cells(220watts seup) with stock 68mm SF(get the SFM -Taiwan 6 bladed available at JH) or Wemotec480 and a good Brushless motor.

EDF can be flown with brushed motor.
With such a high rpm required for EDF, the brush motor will degrade or burn out sooner or later. So why use the brushed motor when low cost BLm BL430-3.55KV align motor + SFM 68mm EDF can do the job.
You need at least 30 amps ESC(better get 40amps or higher)

The other good candidate is the Micro-jet from multiplex or China made that uses stock 55mm EDF. Go to my thread on micro-jet edf .
The plane require just mere 120-130watts on brushless motor for a good descent flight and go up to 170-180 watts for hotter setup/flight.

You can also try DIY dupron EDF plane. They are cheap easy to built and flies pretty fast.
My First EDF was a DIY dupron plane.


Cheers
Babylon5

[ER69]

Dear Moderators,

Regarding your PM noted with thanks.
Sorry for posting the BBAFC RC Jamboree thread in DH.
I am really shock & sorry to hear such a reply from DH.
My intention is to share infos with others and I always thought that this is a place to meet and to share our hobby.
Since you had stated it so clearly that my posting are not welcome in DH, I really have nothing to say.
Anyway, Appreciate if you could delete all my posting in DH and sorry for sharing my build threads with the rest of the members in DH.

Cheers
ER69

[pakana]

why is the su-27 definitely not a good choice for first edf? whats the difficulty? building or flying or both?:)

or is it like mc people keep saying you shouldnt buy a litre racebike as for your first bike? :sleep

for a while ive been thinking of getting a plane for me and i want the su-27! building will not be a problem for me but flying is another thing. maiden flight especially. perhaps i get back to building after that :L

[Babylon5]

Hi Pakana, if you go thru the thread and others ,this plane needs alot of power and buliding it right to fly right.
Many people will tell you they successful hand launch this plane EDF version. On the other hand there are folks out there who did not sucessfully flew this jet on their maiden.
Even in a pusher version I had my failures too.
As I said before if you never try it you will never find out. ..but believe me this plane ain't as tame as a lamb when you first maiden it. :z

Good luck to you.
:D

[pakana]

thanks for answering babylon!
so far ive managed to find only two threads about this plane, this and the other on rcgroups. is there more..?
as i mentioned im quite fascinated with the flanker and only thing that bugs me is that it requires two motors which like you said need to be top notch for the purpose (esc too). so all included its gonna cost more than a single engine jet.. :bh

if 68mm fans are to be used would a pair of typhoon edf 2w motors (4580kv) be enough to push the thing up? if i'd get some good 60a (50a-70a recommended) ecs's to couple them what would be the optimum battery?
does it fly good at low speeds? on some forum someone said this can speed up to 120mph :lip: , but you should reinforce the plane first. or not bank at those speeds :)

lots of q's, thats just few things that came to mind, hoping for answer :)

[pakana]

one more: since im likely going to crash it what is the chance i only f**k up the fuselage and not the electronics? can they take hits? meaning taking hits in the foam fuselage not under a hammer?

[Babylon5]

one more: since im likely going to crash it what is the chance i only f**k up the fuselage and not the electronics? can they take hits? meaning taking hits in the foam fuselage not under a hammer?

Hi Pakana, looks like you are very keen on the SU27.
Don't know which kit are you using . I am on Ultra Fly series .
You should always look for sucess in your maiden. I have modified the Ultra fly su27 for both single EDF and pusher with fix landing gear.
First time hand launch the SU27 with a pusher outrunner (no landing gear) result in a broken nose at 2 places.


Assuming you want to achieve a thrust to weight ratio of 1:1 and your plane weights 1000grams.
Assuming your EDF can achieve 30grams(in most cases it is less) of thrust per amps.
The minimun total current will be roughly 1000/30= 33 amps +++.
In most cases you will need even more current and power for shorter take off .


When u are using the 4+++KV motor on twin (I guess on 3 cells lipo on each EDF) will be drawing lots of current. You probably need twin pack LIPOS and that will make your plane heavier. Anything over 900 grams on this plane with such a relative small wing area will make the w/L ratio high so need longer runway and the landing will be coming in hot. In short this plane will fly like a brick.
I do not have experience on the Typhoon motor but I can tell you that this motor will draw very high current on the Wemotec480. Maybe you can ask Warbird for more advice.

For other the twin EDF look at ER69 thread or seek their advice.

BTW where do you fly your plane.

All the best :up

[DennisP]

The small amount of testing that I and others have done when you use a HET Typoon 2W it will draw a lot of Amps and we are talking up in the 50 to 60 Amp range on a Minifan. A modified Jet Hanger Hawk using a Minfan and a Typoon flies great on a 3S2P 2200mA pack CC60 ESC, actually it is two 3S1P packs in paralell so for the SU I suspect you will double this if you have two motors and that is a lot of weight you will be hauling around the sky.

[pakana]

thanks for input guys,
i have ordered an amd su27 kit, with two 68mm 5-blade fans. they look like wemotec but they arent. theyre gonna cost roughly 80 euros, havent received the package yet..
looks like it will be difficult to get this running with higk kv motors since they draw so much amps. on amd forum i asked what motors should i use they said at least 3600kv. how big is the difference in power consumption between 36xx motors and 4xxx motors? i should try to get a lot of info on this before i start getting suitable batteries and other stuff. weight is on my mind but shouldnt powerful engines compensate on the weight:) no batter if it flies like a brick as long as its a fast brick :L

amd also sells this other sukhoi, su-35 with the canards and everything, which is designed to be a slope glider and has a big, overscaled wing, some say it looks horrible but ive been wondering could it be fitted fith twin edf units? would be cool.. ill try to post a link about it if i find,,,,

babylon, i have no idea where im going to fly, propably some nearby grassfield.

im on duty, more later..... :up

[Babylon5]

Hi Pakana, just make sure the 5 blade wemotec clone ....thats what I call them are balance. If they don't balance there will vibrate like m......and probably throw out the blade so do take some precautions.

Best of luck.

[pakana]

good idea babylon, balance is very important..
how heavy is only the model? i could do some calculations concerning the takeoff weigt. and how do you guys calculate how big battery it will need? id like to calculate myself but dont know how.

i was thinking would it be too much to ask for everyone whos ever build this jet to post what kind of motors/esc, batteries, cog etc you are using and describe flight behavior and performance.. what i want to know is how it would fly with 2x2600kv motors?

i found a shop here in finland that sells 2xbrushless motors and 2xesc for 50€. thats cheap!

heres some specs for the A2208/8 brushless:

NiMh: 6-8 cell
LiPo: 2-3 cell
2600RPM
Max Efficiency current: 8~15A (>74%)
No Load Current / 10V: 1.3A
Current Capasity: 20A/60s
Max Efficiency: 78%
Shaft Diameter: 3mm
Weight: 36g
Internal Resistance: 62Mw
Dimensions: 27.5mmx26mm

and here for the ecs:

Cons-current: 20A
Max current: 25A
BEC: 2A
Imput: 4-10NiMh or 2-3 Lipo
Timing: Optional
PWM: Optional
Size: 2x24x7



how do these sound? motors are 36grams, and wont suck so much current so maybe only one lipo is enough? or what do you guys think?

[Babylon5]

Hi Pakana, I think there are flyer like Eric ,Dennis P, Vortices , ER69 and many others who have experience the same SU27 kit and flown sucessfully.Maybe you may want to PM them for more detail information.

I have a SU27 for twin EDF configuaration, is still in the box. Not sure if it is same kit. I will also need their expert help and advice when I built this kit.

One more thing, to get better High electrical power discharge and to keep the plane lighter u have to use Lipo and not NIMH.


Happy building.

:D

[DT8666]

one more: since im likely going to crash it what is the chance i only f**k up the fuselage and not the electronics? can they take hits? meaning taking hits in the foam fuselage not under a hammer?

Sounds like we have another potential hazard here...

Maybe you don't mind your $$$ to crash the plane but I do like to voice out my HUGE concern on safety. I have no idea how good you can handle the plane but this is can be a huge FIREBall when it strike at the right place.

Please please do NOT fly alone and DO Not fly it if you are not sure and for sure don't try it that is near human traffic/housing area and during dry season. If you know you are going to crash it, don't fly. you are risking human life and property lost.

May the force be with you. Please think about it. Please ignore my post if you see no value in it.

Thanks.

[pakana]

i wasnt saying im going to crash it, i said it is possible to happen. if im risking human life when im flying the thing shouldnt i definitefly fly alone to minimize the risks? and yes to me your post is only a little value because you managed not to answer my original question.
a fireball? will lipos explode if i ram them to a wall 100mph? only way i think i could make a fireball with this is if i torch it and fly it to a gddmn oil refinery

so, the question was not: what happens to people and infrastructure when i crash my sukhoi on them

it was: what will happen to the electronics inside the plane if the plane gets crashed



hope im not being a smartass :L

[pakana]

thanks again babylon, most helpful:)