Freewing Su-35 Twin 70mm 12 blade

[xviper]

Just did some ground runups and I want to make sure I have my sensors calibrated correctly.

At full throttle I am seeing about a 150-200 rpm difference in the two fans. I'm showing roughly 36000 rpm if I have my motor pole pairs (4) correct. Difference is around .4-.5% rpm.
Also, what is a good target temp for the ESC's? What is the designed temp range?

Maiden later today around 6pm central time.

Did you do the throttle calibration? Actually 200 rpm out of 36,000 isn't too bad, is it? Can you hear it?
Don't know about ESC temps. With my EDFs, if it comes down hot to touch, I'm a little concerned.
Give your impressions of the maiden. Vid would be nice but I understand if you can't do it by yourself. My hat cam makes poor vids and I don't always have a camera guy with me.

[xviper]

Mine was released from customs yesterday and arrived in my city this morning but too late to get on mail truck. Hopefully, should be delivered on Monday.
Interesting about the naming. Another guy at my field names his planes. I've never considered it. Maybe I'll name it "Putin". If it crashes and burns, I won't feel so bad. LOL

[seaviper]

Just did some ground runups and I want to make sure I have my sensors calibrated correctly.

At full throttle I am seeing about a 150-200 rpm difference in the two fans. I'm showing roughly 36000 rpm if I have my motor pole pairs (4) correct. Difference is around .4-.5% rpm. This is with battery just below storage at 3.6v/cell.
Also, what is a good target temp for the ESC's? What is the designed temp range?

Maiden later today around 6pm central time.

[seaviper]

Mine is scheduled for first flight this weekend. Xviper did you ever get yours out of customs?

edit: In the tradition of the Russian pilots, she needs a name. I haven't named her yet.

[Alpha]

Xviper, yes I had space, I basically shimmed it right up to the point that the doors still closed. The doors themselves are fairly thick because they're foam. Replacing that section of the door with thin ply or plastic sheet adds even more potential strut length.

[xviper]

viper I think you will need to shim the steering servo as well. And it looks to me that you have enough room to do that.

I wish that Mig29 was on the list for a grass capable V2 update.

I'll try a take off as is off our grass and see what happens.
The SebArt Mig-29 has no wheels. It has skids for landing and you hand launch vertically like in my video above. It flies on 4S, <4000mah. I found a shop in Europe that had a couple left and I just bought one. I think they have 2 left now. They sold 3 of them in the last few hours due to the thread on RC Groups.

[seaviper]

viper I think you will need to shim the steering servo as well. And it looks to me that you have enough room to do that.

I wish that Mig29 was on the list for a grass capable V2 update.

[xviper]

2) Depending on your grass height, consider shimming the nose retract by 2-3mm to ease rotation

5) A hand launch configuration is easy... remove the undercarriage, ventral fins, and drop down to a high C 4000.

If you shim the nose gear, will the door still close completely?

My "hand launch" looks like this:

Do you think the new power system is powerful enough to do it? That's what I'm hoping I can duplicate eventually with the SU-35.

[TiredIronGRB]

Are the Gray ones still available anywhere? I really like the gray scheme. I hope I don't wreck this one. It looks to me like it lands similarly to the F-4, which is very easy. Although I have never flown one of these Su-35's.

You have what I call the gray one...got it and the desert camo one from Motion. I land mine slow with high alpha approach.

[seaviper]

Are the Gray ones still available anywhere? I really like the gray scheme. I hope I don't wreck this one. It looks to me like it lands similarly to the F-4, which is very easy. Although I have never flown one of these Su-35's.

[TiredIronGRB]

Sorry to hear about your Su-35 George. What happened to cause that? Thinking of ordering another one myself before it goes the way of the F-18....

I have already had to do body work on this bird straight out of the box. The techniques are different than for EPO. But I can fix it and paint it.
Normally I don't put them in (notable exceptions include the T-45, F-5, and F-104 to name a few;)). Mine normally just get beat to death slowly from hangar rash and transportation in the car. After melting some foam, I did figure out how to paint it. Epoxy is just superior to contact cement in my opinion. I figure the reason they switched from EPS to EPO is that EPO is probably cheaper by the train car load. Or maybe they wanted better crash survivability. I don't know. I doubt it's the latter.

I do agree with the statement from Pilot Ryan in the latest pod cast that the SU-35 would be a good candidate for a makeover. However, if that makeover were to include gluing in the servos, then count me out. To me that is the only drawback to these newer models. I do not like having to extract a glued servo on a brand new model. It tears up the foam and messes up the paint.
And the servos shipping these days are not the best. Having said that, after you replace one or two, they usually last a long time. This is something that could be fixed with some QC. Of the bad servos I have had (one on the A-4, two on the P-51, three on the T-45, one on the Su-35), all of them have had improper soldering meaning dirty tips or oxidized solder or both. The Hobby King LED set I got also had a bad solder.

Anyway, I don't want to sound negative. Just saying it like it is. QC is not the best these days with any manufacturer.

I love the SU-35. I am sure this will be one of my favorite RC models if it can handle our field. I may do the F-15 gear mod.

The black one I had was a gray one I got used and it had been crashed a couple times so I patched it up and painted it black. I pancaked it on a low high speed pass, I have two more that are newer 12 blade versions. I love the way they fly!

[seaviper]

Sorry to hear about your Su-35 George. What happened to cause that? Thinking of ordering another one myself before it goes the way of the F-18....

I have already had to do body work on this bird straight out of the box. The techniques are different than for EPO. But I can fix it and paint it.
Normally I don't put them in (notable exceptions include the T-45, F-5, and F-104 to name a few;)). Mine normally just get beat to death slowly from hangar rash and transportation in the car. After melting some foam, I did figure out how to paint it. Epoxy is just superior to contact cement in my opinion. I figure the reason they switched from EPS to EPO is that EPO is probably cheaper by the train car load. Or maybe they wanted better crash survivability. I don't know. I doubt it's the latter.

I do agree with the statement from Pilot Ryan in the latest pod cast that the SU-35 would be a good candidate for a makeover. However, if that makeover were to include gluing in the servos, then count me out. To me that is the only drawback to these newer models. I do not like having to extract a glued servo on a brand new model. It tears up the foam and messes up the paint.
And the servos shipping these days are not the best. Having said that, after you replace one or two, they usually last a long time. This is something that could be fixed with some QC. Of the bad servos I have had (one on the A-4, two on the P-51, three on the T-45, one on the Su-35), all of them have had improper soldering meaning dirty tips or oxidized solder or both. The Hobby King LED set I got also had a bad solder.

Anyway, I don't want to sound negative. Just saying it like it is. QC is not the best these days with any manufacturer.

I love the SU-35. I am sure this will be one of my favorite RC models if it can handle our field. I may do the F-15 gear mod.

[TiredIronGRB]

I like the EPS better than EPO for a variety of reasons.

You won't after you put it ;)

[seaviper]

Here is the roll out. This is my first EPS bird. In my opinion, I like the EPS better than EPO for a variety of reasons.

Overall I really like this bird. Hopefully she will fly this weekend.

[seaviper]

Got everything ready...at least I thought so. While setting up the controls I found a bad elevator servo. Luckily I have a spare. I always seem to get bad servos for some reason.

Anyway, This bird has been an exercise in wire management. I think I have it all sorted. The two receivers are in the blended wing portion of the fuselage aft of the battery. The antennas form 90 angles on their own in that space.
Looking good for a maiden later in the week. I like the lights.

[seaviper]

Received the new vertical stabs today. Interestingly, these both had loose lower hinges just like the originals. A little epoxy in the hinge pockets fixed that. And no foam was melted.
Got the strobe installed in the tail. I have been using some Gel Tacky Glue to hold the leds and cables in place. Works good. It is rubbery like EPO glue and thus easy to remove.

Still have to mount the two receivers and organize the last few wires in the battery bay. But the bottom is all buttoned up.

[seaviper]

Today the bird is finally out of the body and paint shop. Started to do assembly and true to form I am missing the collars for the elevator axles. !@# So, I took a 17g digital servo horn and drilled it out with a 7/32 bit to accept a piece of brass tubing which fit over the axle.
I then drilled a 1/16" hole to accept a small machine screw (probably off a landing gear leg). And there you have it...excellent collars. Construction resumes.....

[seaviper]

Thanks for all the good info Alpha.

Well mine will have tailerons, flaperons, and rudder brakes and all other sorts of programmed stuff. I have so much extra stuff in there that she looks like a flying electronics bench...which she kinda is.

It's been a fun and challenging build so far. Melting parts is not good...reading is your friend

[Alpha]

The stock PNP is a lot of fun especially with the V2 PNP's stock 12B power system. None of the mods below are required, but since the questions were asked, here are a few bits of input from my experience:

1) The stock PNP can enter and depart flat spins with ease and execute a wide variety of the lengthy maneuvers in your video, without the need to add slats or LEVs. In fact for weight and wing strength concerns I wouldn't recommend adding them. Flaperons aren't needed, either, but sure, add them in your radio settings in you're so inclined. It won't hurt. High alphas and cobras are easy with the 12B power system without them.

2) Depending on your grass height, consider shimming the nose retract by 2-3mm to ease rotation, although if you're tying in flaperons you likely won't need to do this. Canting in both rudders will look neat, but not necessary with the 12B power system, and consider also that the Su-35's vertical stabs aren't angled like an F-18, F-22, or T-50, so the effect you're after is less in play. If you're using 16 channels, you might as well consider mixing throttle, gear, and your rudders, such that when throttle is below 5% and the gear is down, pushing the elevator stick 100% forward will splay both rudders outwards for a braking action. In practice, on grass it won't be doing much, but at latest least it will look cool.

3) The main struts are Oleos, so standard precaution applies to minimize the rearward force during landing. Consider swapping to my generation of aluminum hub (F-14).

4) Lights... we don't have any lenses specifically for that bird. You may need to get creative, perhaps mixing lenses from the 90mm F-14, F-15, T-45, etc.

5) A hand launch configuration is easy... remove the undercarriage, ventral fins, and drop down to a high C 4000. Glass or Modpodge the nacelles, but don't overdo it. Fiberglass tape painted over works great and is more durable on grass. The Su-35 won't fly exactly like the MiG-29, but it will get you close. Also, wrap the fingerholes you cut in with fiberglass tape. If you're extra finicky, remove the associated gear plastic parts (including door servo and string steering servo) to reduce more weight then tape over the nose doors and mains holes to reduce drag.

6) Decal backwards... I didn't notice that but I'll make a note to see if Freewing can change it the next time they print more decal sheets, although when that would be, I can't predict.

7) If you're after absolute weight savings for a hand launch configuration, try locking your nozzles for a few flights. You may find that you can achieve your preferred flight characteristics without TV and relying solely on your control surfaces for authority. If that's the case, ditch the TV servos.

I ended up keeping TV but ditching the wing servos and rudder servos and flying tailerons. Very light, very simple, very acrobatic.


8) Don't fret if there's minimal slop in the TV nozzles. If it bugs you, clamp them together tighter then feed in dry graphite to lubricate the action.

9) If you're looking to optimize the aircraft for speed, ditch the ventral fins, sharpen the TEs all around (very easy to do because the Su-35 is EPS), ditch the TV, and lock the nozzles. The TV nozzles are very draggy, so replacing them with a properly scaled tapering exhaust outlet will improve thrust. Experiment covering the cheaters, too. Ideally relocate them closer to the fans.

10) Get comfy removing wings if you don't have a van or truck.

[TiredIronGRB]

That IS FoamTac for sure. Very surprised it did that. Will have to watch out. Mine is still in customs, so I don't know what glue comes with it. Now, I know.

Foam-Tac is not EPS friendly...use Bob Smith Foam-Cure, great stuff.