Home made Depron SU-27 Flanker twin EDF

[allintheair]

Hi there!

After having built Thomas Nelson's pusher flanker (and crashed it after a few dozen of flights...) I decided to rebuild this plane but with two ducted fans. The WemoTec minifan 480 seemed to be the first in size that produces acceptable performance. This also meant that I had to upscale the original plans to fit the fans. I think I succeeded by upscaling the plans with 50% and made the wings just fit on A0 paper format (i.e. 83cm).

There is still a lot to figure out so I just hope there is nothing to regret when a parth has just been glued in place.

Original plans can be found at http://www.foamyfactory.com/jets.htm
My intermediate plans can be found here http://www.xs4all.nl/~mbolier/RC/su27_150b_dxf.rar (sorry, only dxf for the moment).

For those who are interested: a video of the pusher Su-27 http://www.wxs.nl/~mbolier/media/Flankie1.wmv

Specs:
Material Glassed Depron
Wingspan approx. 83cm
Length approx: 110cm
Fans 2*WemoTec 480
Motor 2*Mega 16/15/2
ESC Probably 2*ASSAN
No landing gear but bungee with dolly.

I just hope I can give a nice contribution to this forum.

Marc.

[Tanguy&Laverdure]

Just saw your plans. Good job :)

[allintheair]

Some pictures, more will follow as soon as camera wants to cooperate with me again.

[Thomas Nelson]

Very cool, Marc - and keep the progress pictures coming! What do you figure for an AUW?

[RCParkflyer]

This should be a great jet when completed :)

The DXF file won't open for me :( I'll have to wait for a PDF

[Jevgenij]

my Su-30 :D

[allintheair]

Thanks for the encouraging words!

@Jevgenij: nice bird! How is your taileron construction? When I get to that point I'll see how to fix them, probably I'll use a cf rod right through the trust tube.

@Thomas: I have not made an estimation of AUW yet. It will mostly depend on the batteries (low weigh (2s lipo or nicd) v.s. high power setup 3s lipo).

I am really struggling with the question "Should I add a wing profile or keep the flat depron profle (just rounded leading edge and sharp tail)".

Unless somebody has a good reason to drop the flat profile I will keep it. The alternative will be using MH43 and involves some work such as cutting the wings from the plane, create wood templates, cut, sand, .... and finding the new C.G. for the modified wing

Is it worth the trouble?

Thanks,
Marc

[Tanguy&Laverdure]

my Su-30 :D

OMG! so L O V E L Y!! :eek:

Can you tell us more about your Su-30? Thanks

[Tanguy&Laverdure]

and finding the new C.G. for the modified wing

http://www.acig.org/artman/publish/printer_288.shtml ;)

The Su-27 on the other hand cannot achieve full AOA and G ratings until internal fuel has been reduced to 60% ( (assuming that the maximum fuel load has been carried), meaning that a long range mission must account for not being cappable of efficent close-range combat until 40% of the fuel has been used. The technical reasons behind this limitation are simple; when fuel is reduced to by 40% the No.1 fuel tank, located behind the cockpit, and the No.4 tanks, located in the wings, are emptied. The importance of this lies in the No.1 tank which when full has an adverse affect on the plane’s center of gravity, moving it forward of the optimal balance. Thus when it is emptied the plane’s manvering cappabilities rise sharply. This fact means that the mission planning has to be very precise when it comes to the fuel – which is easy during training, but something almost impossible under real combat circumstances. In the case of any kind of unplanned engagements the plane has to get rid of fuel overload; jettisoning BVR missiles is also a very real possibility as they constitute a weight and aerodynamic penalty. Only once the Flanker is lightened to a certain extent it is highly maneuverable. However the Su-27 does possess an analog fly-by-wire system, something not employed by the MiG-29.

[RCParkflyer]

My intermediate plans can be found here http://www.xs4all.nl/~mbolier/RC/su27_150b_dxf.rar (sorry, only dxf for the moment).

Hi allintheair,

I am having a very difficult time with your dxf file listed above. I cannot open it into something usefull. I have tried to re-name the file, changing it to a .dxf filetype, but nothing shows up on the CAD screen. If you can up-load the file directly to the thread, or maybe e-mail it to me at rcparkflyer@yahoo.com that might be better.

Thank you,
Tom - Milwaukee

I'd like to add this file to Thomas Nelson's SU-27 Page on my website www.parkjets.com once I have something that is correct.
Thanks!!

[Happy|Harry]

it's a rar file and needs to be decompressed using winrar ;). i've recompressed it using the zip format and attached it, hopefully this is ok allintheair? :)

phil

[RCParkflyer]

Is this what I am supposed to be seeing?

[allintheair]

Ik looks like you are missing some layers. Please Google for a freeware version of Voloview. I cannot place a direct link here because it is copyrighted. Mail me if you keep having trouble....

These plans are only upscaled and modiefied to fit on A0 format. Some sections cross so at least two prints should be made (or tape after cutting...). I hope to continue within a few weeks and will update the plans when the major building has completed.

There is one essential modification that is not in the current plan: the rear part is made a bit wider to fit the EDF's.

All plans are free to modify & distribute.

Currently I am still deciding if I should cut off the wings and add some MH43. That means that I also have to make a foam cutter.

[Happy|Harry]

i've attached what i see in acad05 and i've also saved it in acad2000 dwg format and attached it too to see if that will open any better in your cad program :)

phil

[RCParkflyer]

No Joy :( I think it only opens DXF files I'll wait till the PDF Template file gets made, Thanks for all of your help!!

[dhelms9138]

Can we get a .pdf file for this plan?

[RCParkflyer]

yeah, me too :)

[Happy|Harry]

ok how's this, A0 pdf of the above cad file :)

phil

[allintheair]

Hi,

One important thing is not in the current plans yet. I have widened the tail 1.5cm (.59'') on each side to fit the minifans. I have another employer and have no access to Autocad anymore so i have to find someone to update the drawings.

It's funny how this thread revived. I feal really ashamed that i started this but never finshed it. It's a matter of time, priorities, other projects, kids,...

Anyway this is my progress:
* Cut out all parts as per plan (read note above!)
* I have ordered a pair of glass inlets from savagelight.com. This saved me the time to engineer a nice pair of inlets.
* I made a depron aligner by pushing the minifan to 2 sheets of 6 mm depron. and glued these together. This will make minifan alignment with the inlet easy.
* The minifans are mounted with a few strips of plywood glued on the depron.

At this point i stared at the model to the model for a few evenings wondering how to create the MH43 wing profile. I have made the profile in plywood but still not fogured out how to transfer this to the wing. The best bet is probably to cut off the wing but i still hesitate to do that.

I will make some pictures if you are interested.

Marc

[chewytm]

Hello,

How's the build going? Is the plane flying yet?

Regards,
chewy

[allintheair]

After a swift start the flanker is now catching dust. The project stopped at the point where I had to decide to cot off the wings and create a mh43 profile (I made the templates already) or leave the wings flat. There are just too many other things going on. I will pick up this project in the building season!

Marc