Freewing Su-35 Twin 70mm 12 blade

[seaviper]

This is the paint scheme I am thinking about

[HangarQueen]

Glad to hear you're picking up the SU-35 again, literally. Nice paint scheme too, I'm curious about visibility in the air.
I'm currently working on moving the main landing gear forward, to reduce the distance between it and the CoG. On this model, the main gear is far behind the CoG, which causes the problems with "leaping into the air" on takeoff.
I didn't really have a problem with that until I installed trailing-link struts, moving the wheel more aft of the CoG. Since then all of my takeoffs became some sort of cobra maneuver on their own.
I have been flying with a CoG of 155mm; I will be moving that to 160mm for the next flight to see the effect. I will also start experimenting with flaperons, which could also improve takeoff rotation.

[seaviper]

Well here is where my CG is (will be).

As you can see from the video, mine didn't have any bad habits on takeoff. I DID use TV on takeoff as well as flaps with tailerons. I found that flaperons caused some weird yaw action when the aileron function was used with flaps down. So whenever I have flaps, my ailerons are off and the tailerons are active. I have not had any problems with her leaping into the air unexpectedly. On landing I do usually disable TV.

On this build, I am incorporating the changes I made for the last bird, as well a new one.

1. modified the battery tray with new wood to accept a proper strap. Also put rubber on battery tray floor.
2. lined the ESC bay with aluminum tape for heat protection
3. installed the pitot tube in the nose cone for airspeed sensing (to be mixed with controls later on)
4. installed a lighting system
5. had to make a new plywood mount for the nosewheel steering servo because the factory had messed it up
6. changed out the esc vent screws and motor hatch screws for the correct length ones !@#$
7. (the new one) added 8 magnets to hold the wire cover on the bottom of fuselage.

Electronics have all been tested. She is almost ready for paint.

[HangarQueen]

Nice going!
I have the pitot too (N2 sensor), and I measured straight-line airspeed of 155 kph on one pass. I have no idea about the accuracy of that measurement, but for me (and for my experience) that was fast enough to enjoy.

Getting back to the takeoff "bad habits", I didn't have any of those either at first. With the stock powder system, I did have a little problem rotating late (on a concrete 80m runway), so after the crash and restoration I upgraded the motors, and I installed the HK brakes.
First flight after restoration, I had a smooth takeoff (using TV sure helped), but landed a bit hot and had to use the brakes. And boy, did it stop.
But the result of that action can be enjoyed in the pictures below: one seriously deformed gear strut, and the tyre sheared... I guess it could use some sort of ABS...this is a ship's anchor being dropped at full speed.



So I left the brakes out, and replaced the struts with the Freewing F15 trailing-link struts, which can take a drop-test from 10m up from the looks of it...very solid indeed.
But ever since I started using those, the SU35 developed the "bad habits" on takeoff. So now I'm trying to experiment with the main gear placement, to see if that changes anything.

[seaviper]

155 kph (96 MPH) sounds about right for normal flying. The best I did with the grey bird was 106 MPH. But most flights were at about 96 MPH.

[C17loadmaster]

Looks good! I like the magnet idea. I did the same thing with the aluminum tape on the ESC bay. I also used a 70mm f-16 intake cheater instead of the old small one, The airflow should be a lot better through there. I’m thinking about adding a semi hidden port on the aft end of the cable bay so the air travels down the channel and out the back. I have the wood battery bay tray and strips of wood running the full length of both sides. That way the top and bottom halves of the fuselage are actually secured together. If you need nomenclature waterslide decals I already created them. Which took forever on my computer.. Its the first time I have made them but think it’s kind cool. I made multiple sets, and 901 is the only other prototype SU-35 so the small decals are the same.

[seaviper]

Hey C17, I have made those water slide decals myself for other planes. They worked nicely. On this project, however, I made a custom order from Callie Graphics. I'm doing mine up in the Gromov Flight Research ACE scheme. The prototype is actually an SU-27, but I like the scheme. I have the bird masked and ready to paint. I'm waiting on the decals to arrive so I can match the blue.

[C17loadmaster]

Oh awesome. Yeah, I saw the air brake. I use Callie all the time as well. It would be awesome to put a F-15 airbrake on the model. I actually have one from my first F-15 that I got to keep for free after it was smashed by UPS. It was an ARF plus, and Motion sent me a high performance version to replace it. So I got an entire plane full of parts. Good luck on getting it done. Like you, I have now gotten into telemetry. It’s pretty cool

[Marktur]

Hey guys, wanted to say hello. I got the desert camo version this week, just finished putting her together. The only mod I've done so far is one that I haven't heard anyone else mention, and that is to make the nose cone removable using magnets, like the other Freewing jets. I usually store my jets up against the wall on their noses...

I'm also a Graupner MZ-24 convert - really like the radio over Spektrum - just feels better in my hands, and so far I really like it. Of course I can't find online support to setup the TV but I did find a YouTube video for Taranis and Spektrum setups..so I'll figure it out. :) (But if you have any suggestions, I'm listening!)

Also - I'm reading that 6000mAh batteries are great in this jet. Anyone using the HRB 6000's https://www.amazon.com/gp/product/B0...89RF8KCG&psc=1

Finally - best CG location, and with gear up or down?

[Sam CB]

Finally - best CG location, and with gear up or down?

For my SU-35 i had my CG configured with gear down. I did that because on the model, gear-up position shifting CG forward (gear retract forward). That way, during landing, i know i have good CG. However, that means while flying with gear up, it will be slightly nose-heavy and i don't mind that.
IMO you should always try to have good CG with gear down position. You don't want to be tail-heavy while landing.
Sorry, forgot to mention that my CG around 165mm with gear down position.

[gazza]

just got mine, the marks that are on the TV are not very clear, hope ive got them lined up correctly, or i can see it being a very short maiden flight

[xviper]

just got mine, the marks that are on the TV are not very clear, hope ive got them lined up correctly, or i can see it being a very short maiden flight

They are more like indentations and aren't on both sides and top/bottom. If you can't see them, that means they are rotated too far and hidden inside the shroud. Remove the rods and move the nozzles around and you'll see them.

[JLambCWU]

Are the decals different from the stock ones? Love to see them. Doing a Ukrainian digital camo on mine.

Looks good! I like the magnet idea. I did the same thing with the aluminum tape on the ESC bay. I also used a 70mm f-16 intake cheater instead of the old small one, The airflow should be a lot better through there. I’m thinking about adding a semi hidden port on the aft end of the cable bay so the air travels down the channel and out the back. I have the wood battery bay tray and strips of wood running the full length of both sides. That way the top and bottom halves of the fuselage are actually secured together. If you need nomenclature waterslide decals I already created them. Which took forever on my computer.. Its the first time I have made them but think it’s kind cool. I made multiple sets, and 901 is the only other prototype SU-35 so the small decals are the same.

[C17loadmaster]

Are the decals different from the stock ones? Love to see them. Doing a Ukrainian digital camo on mine.

Yeah, they are the correct ones. The Freewing decals are correct on the stars and some of the anti collision lights. The rest are wrong. I have been literally working on this plane for about 9 months.That being said, I have had a bunch of other planes I have been spending time on. One day I will just commit to this and finish it. I have no idea what the weight difference will be between it and my other "flying" SU. I'll be sure to post the weight difference in the end.

On the pics... that canopy is a scratched spare I have on for the build only. There is still a ton to go, but copying images and trying to replicate parts with stuff around the house is time consuming.

[Alpha]

Hey there C17loadmaster, if you wanted, send me your decal references and/or files and I can see if I can get Freewing to update their decal sheet. The bird is almost ten years old at this point, but perhaps they'll bite.

[simonslim]

Do you guys remove the front strut brace or leave it on. Mine dislodged on take off after clipping a small stone and was ingested into the port fan, destroying it. I've since removed the brace.

[C17loadmaster]

Yeah you should keep it. The nose gear needs all the support it can get. I posted on this thread about a year ago to get it mounted solid. I drilled through the support and ran a small bolt through, securing with 2 separate nuts. One is meant as a lock nut, just to hold the first one at the ideal tension. I think I put a very small amount of silicone grease where the pieces are pressed together.

On one of mine I also built up a support for the other end as to prevent the nose gear from being bent backwards. There is a lot of force on the two wheel nose gear during landing and takeoff... especially on grass.

[xviper]

I did something similar to C17. Additionally, I epoxied a carbon square rod to the inside center of the brace and I made a wood block and glued it in at the end of the slide. There is too much space for the brace to slide back and hammer against the end. But if you hit it hard enough, nothing will hold and something else will break.

[C17loadmaster]

In addition, I used a bent landing gear strut that I repaired enough to allow the spring action to function properly. I cut off as much of the shock’s tube and compression piston that I could, used a grinder and sand paper to smooth out the sharp areas, and mounted it to act as a shock absorber for the brace. When the gear is extended, there is no open space between the two. The two of those modifications reduced the amount of contact area that the fuselage would be under a lot of stress. I have not had any problems since then.

[Marktur]

Hey guys, quick update...LOVE THIS JET! Flying with 6000mAh HRDs, landing at 3.5 minutes with 35%+ left...they have only been cycled about 5 times so I'm sure I can extend the time over the next month. I love the way she floats! Very forgiving on landing, and plenty of power - not endless vertical, but not feeling the need to upgrade anything. I haven't been doing any 3d stuff... lots of compliments at the field, however.

I had a hard landing on the 3rd flight, the front gear broke...fixed it, broke again, this time we just poured a ton of Gorilla glue and sprayed a bit of water, and the whole thing is now much stronger than the rest of the jet! Hasn't been a problem now in over 20 flights.

I'm running CG at the spot in the picture above - the wire channel for the ailerons. (Thanks seaviper). With the CG further back, it got weird and unstable. I actually glued a few bolts inside the nosecone for a bit more weight up front, and push the battery as far forward as it can go.

My only issue with this jet (and I know I just need to fly it more and adjust a bit..) is that the elevators are very sensitive when inverted - really wants to balloon very easily - so I can't seem to do a nice 4-point or slow roll...not sure why it acts one way normal and different inverted, or the "right" way to fix it - hate just throwing in more expo blindly. Ideas?