Hi Guyz,

Sorry it's been so long since I updated this. Anyway, for whatever reason I got it in my head to build a Mig-29 out of depron using the same building techniques I learned from building the jetset44 family of Sukhois 27 and 37. What put it over the edge was a 70mm EDF/50Amp ESC/4 servo combo from HobbyPartz for under $50. I got 2 and have my power system. I decided to design thrust vectoring into the model using the HobbyLobby TV nozzles either from the Su-34 or the F-35, but not sure yet. Right now it's looking like the following:

Wingspan - 33"
Motor - 2 x 3000KV
EDF - 2 x 70mm
ESC - 2 x 60amp
Battery - 4S 4000mAh
Servos - 9, 2 x Ail/flaps, 2 x elev, 2x rudd, 3 x TV (roll, ptich, yaw)
Thrust - ~72oz
AUW - 60oz

Here are some images of the initial design. I've started breaking it out into parts but there is still a long way to go before I can get a working prototype.

Vic Attached files

 

During this build process I decided to make some modifications to the nacelles. The existing design called for a built-up nacelle that would "box" the EDF in along with the TV nozzles. I would then design supports around the EDF and TV nozzles to hold them in place and well as provide additional foam for sanding the nacelles into their rounded final form.

Now I am playing with a design that would use a single piece of foam that would curve around the EDF and TV nozzle, thus creating the rounded form without sanding. The front intake of the nacelle would still be "boxy". Anyway, a picture is worth 1000 words so this is what I initially came up with.

Vic Attached files

 

That looks very nice- a rcp/Shumate hybrid. I really like how the mig 29 v1 flies and as I just posted to you in the su37 thread this plane in the that wingspan would be great. But the wing loading on my su37 at 65 oz was too high at 36 inches. Flying straight and looping was okay, but any slow flying or cobras or tumbles cause wings to stall out. I had to do a tumble, then point the nose down to build airspeed. If you look at My su37 videos you'll notice that it took me a while to figure out that trick. A couple times I did a maneuver and it dropped like a rock afterwards. That was with the twin 70mms. As soon as i brought wingspan up to 40 inches the problem was solved. Anyway, that's my 2 cents. Of course, for fast flying the weight may not be as bad.

 

Sorry for the long delay between updates. I've been working on the design since I decided to go up to a 36" wingspan. I had to rework it in Sketchup. Increasing the top part of the model (sans nacelles) by 10% (about) then reworking the thickness of the foam back to 6mm. Anyway, it is done now. All I need to do is decide where to put the servos for the TV nacelles, make a pocket for them, a cutout for the EDF units, and slot for the TV nacelles to fit into. I also added another hatch to access the electronics in the fuselage, a lesson learn from my Su-37 EDF. Anyway, here are more pictures of my progess in sketchup.

Vic Attached files

 

Just a quick update. I added alignment tabs for the TV nozzles and finally created all the G-code for the printer. I should be cutting out some parts real soon and test fitting them. I will make sure I take lots of pictures.

Vic

 

vicentel,

What are you using for a TV Nozzle?
I'd like to try one one those.

Thanks for your help.
George

 

I think he said they're from the Hooby Lobby Su-35 EDF

 

This is the one I'm using:

http://www.hobby-lobby.com/360_degree_thrust_vector_nozzle_for_su_34_390759_prd1.htm

Vic

 

Thank you !

 

Finished cutting out all the foam parts. I may have to re-cut the nacelles, it seems the channels were not cut deep enough to get the correct roll around the EDF.

 

I finally started cutting out the parts and gluing them together. The wingspan is 37". I also starting test fitting some of the parts to make sure they fit properly. I even had to cut some part over because they were not cut properly to begin with.

Vic Attached files

 

Here's some more pictures of my progress. As you can see I cut out some more parts and test fitting them. I also installed the carbon spars for strength.

vic Attached files

 

Here is an update of my progress. Mostly cutting out the foam and test fitting over and over again.

Vic Attached files

 

Have more pictures. Got some more stuff done on July 4th, however not as much as I wanted. I wanted to have a little less parasitic drag so I beveled the leading edges on the wings, rudder and elevator. I added carbon sparring to the rudders and cut out the control surfaces of the rudders. I also added a reinforcement at the root of the rudder where it meets the fuse. I finally soldered all the connectors for both 70mm fans and tested them. Static thrust tests show a single 70mm fan at WOT draws about 34amps max, and produces 40oz of thrust. I cut out the nacelles, built the EDF mounts and test fit them. Hopefully the pictures a self explanatory.

Vic Attached files

 

I started more electronics testing. The 70mm/60Amp Detrum combos I purchased advertise no BEC but I just tested it and there is in fact a BEC. I started looking online and people are saying there is a 3A BEC on the 60A ESC. Thinking there was no BEC I went out an bought a Castle Creations 10A BEC. I'm thinking of keeping it for this plane just in case. The plane will eventually have 9 digital metal gear micro-submicro servos. I have a similar plane with 9 servos as well on a 3amp BEC (Proton 40A ESC/3ABEC) and it works fine.

Also, I'm still torn between full flying elevator or hinged. I full flying elevator I will have to reinforce the mounting points and it will look real cool. The hinged elevator will not look as cool but will definitely be easier to implement. I can't decide.

Here are some more pictures to update the progress. I cut out thrust tubes and testing their fit. Also doing a lot more beveling of foam. Attached files

 

I didn't like the efflux tubes I made with mylar (transparency film) so I decided to use Styrofoam cups instead. This cup trick seems to work better in the sense that the exhaust tube maintains its shape better.

The close-up of the EDF shows that I curved some foam around it as well. This is to give support to the nacelle because of the gap the intake lip of the EDF creates when the foam is wrapped around it. The support is necessary for the serveo that will be attached to the nacelle for the TV nozzel.

I also started to test intake ducting using Styrofoam cups as well. I'm still debating as to whether or not to use them. Attached files

 

I started working on the nacelle cheater holes. I beveled it so that air can be sucked into them more easily. I also worked on the nacelle supports by laminating them and beveling them, again to smooth the air getting sucked into the fan. Obviously this needs to be done twice for both nacelles, mirror images of each other.

Not pictured is the continued work on the intake duct and exhaust duct. Just making sure everything is aligned properly proper air flow. Another decision I'm trying to make is whether or not to have the ESC and wires in the intake part of the nacelle or have it outside the nacelle. I've done both in previous EDFs and have not really noticed a performance difference. Now it's just aesthetics and the amount of work. I am leaning towards having the ESCs and wires in the nacelle to hide them but this is the "more work" option

Vic Attached files

 

Hey Guys,

I got a lot done last night. After going over in my head the sequence of events to construct the nacelles, route the servo wires, install the EDFs and associated wires, ducting and TV nozzles - I finally took the plunge and did it!

Vic Attached files

 

Here's some pictures of my progress. I got a lot more stuff done I decided to finally commit to the full flying elevons. I modified the rudder design to better reinforce the full elevons. I installed bushings for the elevons. I glued down the rudders and hot-glued the rudder servos. I also started hooking up the servos to the receiver and testing the connections. Lots of sanding and beveling. This build takes a lot of patience with the sanding but it is totally worth it. It is starting to resemble a Mig-29 now.

Attached files

 

So I decided to go with two layers of foam for the elevons. You can see reinforced the elevons with carbon, then laminated the second sheet and installed the control horn. Test fit looks good.

Vic Attached files

 

That really looks good, Vic. The black nozzles look so cool with the white foam. EXCELLENT!!