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Build Log
Mig-35 Twin EDF w/ Thrust Vectoring
Hi all,
I am building a Mig-35 (Mig-29 w/ all hop-ups) with twin Hyperflow EDF's, ~600 watts, and thrust vectoring. Some of the jet was based on John Bright's Mig-29 plans, but most of it I just scaled off of pictures. It has about a 31" wingspan, and I hope it will weigh less than 30 oz RTF. I plan on glassing the whole thing before paint. It will use 5 channels, 1. THROTTLE 2. ELEVON 3. ELEVON 4. THRUST VECTOR YAW 5. THRUST VECTOR PITCH. Thrust vectoring will only be pitch and yaw, no roll as of now. The thrust vectoring units are made of carbon and foam. The cone is 3mm depron foam , the outer ring was cut out of an Alpha 60 mm fan unit (finally, I found something this fan is good for ), and all mounting and pivoting hardware is either flat carbon or small carbon rod. This is a rather simple gimbal made with the strongest and lightest material I could find. The entire vectoring unit weighs around 12 grams (plus the weight of 2 servos and 3 push rods). I hope to have her flying within a week or two, but I definately want to take my time to do it right. Thrust vectoring demo video here https://www.rcgroups.com/forums/show...10#post7913311 |
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Last edited by tailslide5_0; Aug 08, 2007 at 01:06 PM.
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Thanks. The plans will be one of the last things I accomplish, after I get her flying and such.
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I have 'remodeled' the rod that connects the two outer gimbal rings w/ a tube that is epoxied into holes drilled in the rings.
Basicly how the gimbal works is the carbon unit moves up and down on a horizontal axis, and the foam cones move side to side on a vertical axis. The pics explain what I mean. This assembly only weighs 8 grams. |
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Last edited by tailslide5_0; Aug 04, 2007 at 09:29 AM.
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Very Nice work!!!
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Here are some updated pics of her right now. She's not too far from her glass job.
Along with the turtledeck(s) being installed, I mounted the elevon servos in the underside of the rear section. I plan on mounting the flying elevators similar to the HET F-16. A brass tube will be glued into the elevator, and it will pivot on the carbon rod, and be secured w/ a wheel collar. More to come soon.... |
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Here is a sweet video of a single-seat Mig-29 w/ mostly the same capabilities as a Mig-35. The best part is definately right after the takeoff.
http://www.youtube.com/watch?v=PWLYTAYG-9U |
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I took the advice of my LHS owner, and decided to make sure the Mig flies ok before I put too much time into it (glass, fill, etc.). I am going to maiden her this morning. Hopefully, I'll have an opportunity to try out the thrust vectoring too.
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Well, she flew good until I tried using the vectoring. I started with a little left thrust, and she yawed a little, so like an idiot, I jammed it all the way left. She did a funny snap roll, and when I let go of the rudder (left vector), it continued to spiral. I chopped the throttle right away, but it didn't help too much. Straight in nose first.
Once I got her home, I investigated what could have done that, and it turns out that the control horn on the right cone had popped loose, and the cone was stuck in left yaw. The damage on the fuselage is only from the nose to the aft part of where the canopy sits, so she's definately rebuildable. I didn't like the shape of the nose anyway. |
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Quote:
I was just posting a note to say that I don't think that yawing the nozzles will provide the effect you desire. I know that the full-size Su-37 and F-22, both use elevon mixing on their nozzles. It stands to reason that the full-size MiG-35 uses the same type of mixing as these other two aircraft. How difficult would it be to change the mixing? Can you easily connect the nozzles to the tail feathers? |
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Hi Dan,
It wouldn't be too hard to change the vectoring to being capable of roll. Another servo and another channel would do it, and would make it able to do roll, pitch, and yaw. If I hard mounted the cones to the gimbal rings (took out the yaw capabilities) then I could do roll and pitch using the same servos and same # of channels. Honestly, I'd like to be able to do what the Mig does in the video I posted earlier. The only way to do that would be w/ some yaw, so I think I'll keep it the same for now. As far as connecting it to the elevons, it would be somewhat tricky, but I wouldn't want to do that anyway cause I want to be able to turn the vectoring on and off. As of this morning when I flew it, the yaw was controlled by the rudder, so it was always on, but the pitch didn't move until I flipped (what would be) the gear switch on my Tx. |
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Here are two pics of what she looks like now. All of the damaged foam was cut away (it was too ugly to take pics of it all dorked up). The turtledeck popped off in the crash, but was undamaged and should be easily reattatched. As you can see, it should be easy enough to splice in some new foam on the front end.
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Quote:
Here's a couple of links:
http://www.airsceneuk.org.uk/airshow...ovsky/maks.htm At the very beginning of the video, you can see the nozzles yawing from side to side. |
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