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Old May 18, 2007, 02:23 PM
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ectomia's Avatar
Caterham, Surrey UK
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Build Log
Twin 90mm GRP MIG 29 Design and Build

Hi all just thought id start a build thread about the twin 90mm edf Mig 29 im building for a moulded kit form which I hope to produce from ( i have had many enquiries over past few months from fellow modellers who`d be interested)

It will use either AP900 or Midi fan for power.

Below is the scale it will be produced at (see 1m ruler on board as reference) and this is the design for the mould.
Accurate detailing and markings will be produced in the mould and will be made ultra light yet strong for tighter manouvers.

I will keep you all updated with further pictures soon. Currently am awaiting a new scroll saw to cut all the jig/plug formers (52 of them!!!)
but have started modelling scale working pnumatic retracts for it! so should be a sweet lil kit when finished.



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Last edited by ectomia; May 27, 2007 at 02:34 PM.
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Old May 18, 2007, 02:58 PM
EDF Jet Jam May 2014
Robert Belluomini's Avatar
United States, KY, Crestview Hills
Joined Dec 2000
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I'll watch this thread anxiously! Love the Fulcrum
Bob
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Old May 18, 2007, 03:39 PM
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Caterham, Surrey UK
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should be a good one when its done.
Have had alot of ispiration from the SU27 on this link
http://www.su27.de/inhaltindex.htm

scale works out to be 1/12th and minimal formers in place.

It will be a white gel coat fuselage and wings.
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Old May 18, 2007, 03:44 PM
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I am watching this one, not enough big twins around. Gordon should be keen, he has a couple of ds51 units lying about.
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Old May 18, 2007, 04:04 PM
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Caterham, Surrey UK
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Thanks guys, I too am anxious to get cracking on the fus.
I want to get overall weight for finished frame to about 4-6lb without the battery. I have experience with light planes from about 7 yrs of sloping.
therefor with the thrust to wieght ratio about right when the battery/s are installed.
Would like to test it with 2x DS51`s when can afford it. perhaps if I were to get some sort of sponsering or something it would make good sense to have a variety of fans to be able to use in it.
Mind you has anyone got much experience with the JEPE fans? whats the average static thrust output or maximum??

Have been using Solidworks, Profili 2 and 3DSMAX 8 CAD programs to create the profiles for the design. Was originally thinking of sending them off to lasercut, but again finances cant budget for that.

The undercarriage is a unique design with parts caniblised from Spring air retracts (mainly the cylinders) as they have the output I will require.

Main controls will be for now are;
2x fans
2x 4-5s 5000mah lipo
Taileron servos x2
retracts (spring air for now)
steering servo.

Radio used for flying wil be my fathers (dont know why he spent so much) Futaba FX-40

plans for later after testing;
Mig 29 OVT thrust vector nozzle (again have been designing it based on swashplate mixing from helis)
Scale retracts (home made in moulds)
cheater holes in top of fuselage.
Sports wing
Possible increased diameter for 120mm fan nacceles.

Spent 4 days designing the retracts after careful study of videos of takeoffs and a scale model of the mig.

Has anyone else managed to make fulcram?
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Last edited by ectomia; May 18, 2007 at 04:39 PM.
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Old May 18, 2007, 04:32 PM
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Caterham, Surrey UK
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as for experience with planes my father and I both model IC and electric
heres one of our plane sheds


and our garage workshop (oneside)
we are aiming to get a bigger workspace as its all getting cluttered.
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Old May 18, 2007, 06:21 PM
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ectomia's Avatar
Caterham, Surrey UK
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You can see an example of the thrust vector rig i am going to try when the frame is finished
http://www.rcgroups.com/forums/showthread.php?t=687654

based on this unique aircraft

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Old May 18, 2007, 06:26 PM
smug in granny panties
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NorCal Silicon Valley
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you will get a lot of choke with that setup. it chokes the stream a lot, and on top of that creates funny vortices that degrade thrust even more. you kinda have to make a setup that curves gadually.

Barry
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Old May 18, 2007, 06:30 PM
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ectomia's Avatar
Caterham, Surrey UK
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yes I had guessed something like that may happen, thats why i was curious to know if anyone has tried it on a rc jet?
obviously the movement wont be that harsh on the nozzle
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Old May 18, 2007, 06:35 PM
smug in granny panties
monkamarm2000's Avatar
NorCal Silicon Valley
Joined Aug 2002
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yeah do a search, lots a guys mesed with these setups. I've had the most luck with just plane old plates in there.

Barry
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Old May 19, 2007, 11:08 AM
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GregG's Avatar
Antioch,CA,USA
Joined Dec 1999
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Quote:
Originally Posted by ectomia
.........Have been using Solidworks, Profili 2 and 3DSMAX 8 CAD programs to create the profiles for the design. ......
Great looking start on an ambitious project! Which airfoil did you decide to use?
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Old May 19, 2007, 11:52 AM
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ectomia's Avatar
Caterham, Surrey UK
Joined Nov 2006
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A flat bottom S7055 as I have used this before on a modified ducted fan jet.
May have to thin it down slightly. or could use a Mh-30 profile which should be more stable for higher speed and inverted manouvers.
I will change this if not happy with flight characteristics that I get
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Last edited by ectomia; May 19, 2007 at 11:59 AM.
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Old May 19, 2007, 01:42 PM
smug in granny panties
monkamarm2000's Avatar
NorCal Silicon Valley
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well if your doing a plug you might want to pick a good one so you dont have mismatch on a changed wing to the plug. And along those lines, its easier to blend a semi or symetrical foil to a blended fuse type plane, than it is to a flat bottom due to lex's and underside. Not real hard, just generally easier than dragging a lex down to meet a lowered L.E and stuff like that. As for foil it is a blended body like F-18, F-16, F-15 so its gonna be floaty, you wont need a whole lot of lift. My massive Top gun mig is a trainer with even a symetrical foil. But for jet's I still like the MH foils myself. MH 42 is a great go to foil as is the 43. MH 30 is a good foil, but kinda better for F-3 F-5 guys, very fast but kinda wants flaps when it gets to slow.
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Old May 21, 2007, 03:16 PM
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ectomia's Avatar
Caterham, Surrey UK
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new band saw arrived today, so will start cutting out the plug formers, then align on 3x ali tubes. after that then the 1/32 strips of balsa will be applied.
more photos when this is done.
should probably be at the weekend
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Old May 22, 2007, 01:58 PM
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belgium
Joined Feb 2004
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wood?

do you go for building in wood ?



regards
wim
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