Flex Innovations F-100 Thunderbird, 90mm

[F22trainer]

Good days guys. Just did a successful maiden flight today of the Flex Innovations F-100D. Link to the video of the second flight down below.
I would like to share my experience setting up the Flex Innovations F100D Super Sabre with the Spektrum AR637T PWM receiver. As there is little information about this jet out there.

I purchased this from Hobbytown online store. The total price was 530 plus tax and 15 bucks for shipping. I would not say it is a good deal(will explain more about why). But it is a great jet where you can only find from Flex Innovations.

First thing first, A list of all the onboard electronics:
Spektrum AR637T receiver.
Avian 130A Smart ESC Version A. (from E-flite 90mm Viper)
E-flite 90mm EDF with inrunner motor. (from E-flite 90mm Viper)
Assan AG61 Steering gyro.
Maiden with HRB 6000mah 50C lipo. (845g sit right behind the vent hole)

List of Other modifications:
Robart 3" scale rubber wheels.
Dave Brown 1.75"x12.7mm foam nose wheels. (sanded down to about 1.6" diameter)
A 5" EC5 extension lead. 10awg wire.
E-flite SU-30 Pilot.

Build:
Assembly:
The jet goes together pretty fast. One of the Flap control horns came loose. Had to glue it back on. The vertical fin needs some extra glue to stay in place, so make sure you secure all servo lead connections before you glue it down.
BTW, Make sure you pull all control horns "as hard as you can!" Or you might end at with some sheeeeeeeetshows like my T45 from MRC. (find more information about my experience with MRC here: RCgroup Vendor talk, where customer does not matter)

Receiver setting:
I've seen a few videos that claim that the Aura 8 has some problems. Also, a part of me doesn't want to go through all the trouble to learn a new gyro. So I choose to use an AR637T receiver instead. And hooked everything up PWM with it.There were 3 servos you have to manually reverse when you put them on a Y lead. One flap servo, one elevator servo, and the rudder servo. (check out how you can reverse a servo here. search Easy Servo Reversing Method on Youtube.).

Everything is set up conventionally. No taileron, flaperon etc. The jet has a great roll rate and plenty of elevator&rudder authority with this setup.
Aileron 20mm up&down. measured at the trailing edge close to the fuselage. High rate with 30% expo. Low rate of 70% travel with 20% expo. Note: put the control linkage one hole inner on the servo arm. For better aileron control resolution.

Elevator 38mm up&down. Measured at the leading edge at the fuselage. High rate with 30% expo. Low rate of 70% travel with 20% expo.

Rudder 36mm left&right. Measured at bottom of the rudder. High rate with 25% expo. Low rate of 70% travel with 15% expo.

Flap. Set up by the book. 32mm for takeoff/half. 60mm for landing/full. With 1% and 3% up elevator mix. Measured at the trailing edge at the fuselage.

Electronics:

AR637T and AG61 steering gyro mounted with double side tape. Secured with foam-safe glue. Used the stock Gear door sequencer. Note: With the stock sequencer. If you left the gear down before plugging in. The gear will not go up on your first control of retracting the gear. Only the door closes. The gear will go up once you cycle the switch. You can do this once you are in the air. But I would not recommend it. Best to cycle them and make sure they work on the ground.

The E-Flite 90mm EDF and inrunner motor is a drop in fit. No need to worry about FSA(Fan sweeping area/intake area). You may put a few washers at the mounting point. Just to make sure the EDF is not pressured or deformed by the foam surrounding it. The thin plastic exhaust pipe needs to be trimmed short to attach to the E-flite EDF unit. Wrapping it in half and inserting it from the back make assembling easier. Note: If you programmed reverse thrust on the Avian ESC. Be sure to secure the thin plastic exhaust tailpipe. Otherwise, It may be deformed or even sucked into your EDF unit. causing serious damage even crash! That is why I did not demonstrate the thrust reversing in the video.

I drilled a hole in front of the receiver and steering Gyro. Also, cut off a piece of foam in front of the battery. They will help to cool your battery. As there was no venting for them.

2 marks showcase battery location on my plane. Yours may vary.

CG at the manual recommended position. (maybe a couple of mm forward for the maiden fight) the Elevator is 26mm down below the seam line when neutral.

Gear modifications:
The main strut is a bit too soft. they are partially compressed when sitting on the ground. I added a piece of spring on each side to make it stiffer. So are not compressed when sitting on the ground.
However, the nose strut is on the stiffer side. There is not much weight distributed at the nose. So I cut off 3-4 coils of the stock spring and put a piece of softer spring in it. Combined with Dave Brown's soft nose wheels. This will help with a bumpy hard surface, like our geotextile runway.
Robart 3" rubber wheels and Dave Brown 1.75"(sanded down to 1.6") are drop-in fits. A couple of washers would deem necessary.

I also added a layer of rubber washer underneath the main retract mount. Just to elevate the main gear a little. So it sits on the ground with a lower AOA. Would also help with touching down with main wheels on landings.

Pilot figure:
I have an E-Flite SU-30 pilot around. Was planning to add it to my SU-30. But it looks just right for the F100. The stock pilot is too small.

ESC mounting:
The Avian 130A Version A. ESC is designed to fit the 90mm Viper from E-flite. It has a longer battery lead compared to regular Avian 130A ESCs. However, it is still a couple of inches short to fit the F100. So you will need an extension lead. I would recommend 10 AWG wires at least(more AWG means less Amp, so 12 AWG would not be enough. You can find 10AWG EC5/IC5 to EC5/IC5 extension lead at Horizon Hobby). As it can draw over 100A in a leveled flight.

Feed the ESC from the back, just on top of the EDF mount. Make sure the heat sink is facing downward. I cut a square vent hole just underneath the ESC's heat sink. And secure the ESC with foam-safe glue. Note: the F100 comes with a vent hole on each side. But they are rarely small. So to make it 100% safe. I would recommend cutting your own vent hole for the ESC. This is achievable before you mount the EDF unit in place. You can make the cut through the EDF mounting place. Be careful not to cut the elevator and rudder wire while doing it.

Flying:
The F100 is known to have tip stall issues. So be sure to keep your AOA low in turns and coordinate your turns with the rudder. And always add power in turns.
The jet really glides well. You can land it with power off. Although I would recommend you stay on that throttle and keep the AOA reasonable low in case it gets too slow.
With the E-flite EDF unit. Full ordnance, it gives me 4m of mixed throttle flying with the 6000 HRB pack. Came down with 30-35%. Set the timer at 3:45 if you are flying really hard.
It has plenty of power to rotate. As it has a wing load of only 85-95g/square dm. EDF has a wing load of 150g/square dm regularly.

Final thoughts:
This is a unique military jet on the market. The finish is not comparable to FMS/E-flite. But still reasonably good looking from a couple ft away. The price is a bit high at 530/550 + shipping. Consider I had to take out the Aura8, the stock outrunner EDF unit, and the ESC. I would say, with the stock EDF, 450 would be a better price range for this jet. But it is what it is for the price, coz I don't have any other choices.

Howdy y’all,
You don’t know how much I appreciate the thorough set up and review. While not my first jet, I held off buying this one because of price and a full hangar. But a healthy bonus and the “limited availability “ notation made it imperative to green light this project. Delivery should be Wednesday and I’ll have your notes along for assembly, as I have a rare week off.
Nope, I didn’t abandon you guys just had to learn how to fly a desk and an airplane at the same time.

[xviper]

Since my last post here (Feb/22), I did eventually get this plane directly from Flex Innovations. Sucked it up and paid the high shipping costs. I knew what I was getting from reading all the stuff on the forums, so when I got it, mods began right away. I knew from having a FlexJet that the powertrain was inadequate for me and the Aura 8 was getting pulled right away. In went the 90mm fan from the Eflite 90mm Viper and a reversing ESC. It flies with authority with HV battery and the reverse is great to get it stopped before nailing the grass at the end of the runway. Strangely enough, the small bombs on the wing interferes with the aileron's full movement. Next season, I'll be taking those off.

[Enzo_K]

Since my last post here (Feb/22), I did eventually get this plane directly from Flex Innovations. Sucked it up and paid the high shipping costs. I knew what I was getting from reading all the stuff on the forums, so when I got it, mods began right away. I knew from having a FlexJet that the powertrain was inadequate for me and the Aura 8 was getting pulled right away. In went the 90mm fan from the Eflite 90mm Viper and a reversing ESC. It flies with authority with HV battery and the reverse is great to get it stopped before nailing the grass at the end of the runway. Strangely enough, the small bombs on the wing interferes with the aileron's full movement. Next season, I'll be taking those off.

Glad to hear you have it up and running well. Hope you caught it during their sale event. If I didn't mention the clear exhaust pipe would get sucked in by using thrust reverse. Make sure you have it glued in place (at EDF joints and along the fuselage).

[Enzo_K]

Howdy y’all,
You don’t know how much I appreciate the thorough set up and review. While not my first jet, I held off buying this one because of price and a full hangar. But a healthy bonus and the “limited availability “ notation made it imperative to green light this project. Delivery should be Wednesday and I’ll have your notes along for assembly, as I have a rare week off.
Nope, I didn’t abandon you guys just had to learn how to fly a desk and an airplane at the same time.

👍🤟

[F22trainer]

Looks like I be on the phone, Excited to see how big she was, and delivery was in a typical double box. No damage outside to the shipping box or product package. But alas’ my joy was short lived when I lifted the top tray.

[xviper]

Looks like it was done during packing at the factory. There's not even a hole in the cellophane. If they won't do anything about it, I suggest you use Spackle to slightly over-fill the hole, let dry thoroughly and sand it to match the surrounding terrain. Match the paint and blend it in.

[F22trainer]

Looks like it was done during packing at the factory. There's not even a hole in the cellophane. If they won't do anything about it, I suggest you use Spackle to slightly over-fill the hole, let dry thoroughly and sand it to match the surrounding terrain. Match the paint and blend it in.

They offered to either send a replacement part (from factory) or knock off $$$. So let’s just say they easily paid for the upgrades to the Viper motor and fan unit…

[xviper]

That's actually quite generous. A replacement part would mean a fuselage and could take many weeks.

[F22trainer]

That's actually quite generous. A replacement part would mean a fuselage and could take many weeks.

Pretty much how I thought it through also! Fan unit and motor showed up today too!

[xviper]

Pretty much how I thought it through also! Fan unit and motor showed up today too!

Which one did you get. Is it going in the Viper and the Viper going into this?

[F22trainer]

Which one did you get. Is it going in the Viper and the Viper going into this?

I had already ordered the 90 mm Viper fan and motor, solely for this (T-birds)
plane. I was thinking of using a Freewing 130 amp ESC w/ the 10 amp BEC and same sequencing unit from the T-33. I have a Spektrum AR8360 with AS3X I planned to program for this bird. Similar combo of upgrades I made to my T-33 and it has become a real joy for scale flight, but I put the AR631 in the T-33 and got excellent results. So it would hurt my pride to go with another 631 and save the 8360 for some other builds under way. (SopwithPup 1/4 scale)

[F22trainer]

Heck yeah even the stock fan wasn't bad, I just wanted alittle bit more. I'm not balls to the wall flyer all the time, but it's fun knowing you have it if you want it.

Finally hit the ‘send it’ button…what are the odds you get to vacation out this way again?

[rifleman_btx]

Finally hit the ‘send it’ button…what are the odds you get to vacation out this way again?

I'm thinking very fair odds, as long as the price of fuel doesn't skyrocket again, I've got plans to head there.

[rifleman_btx]

Looks like I be on the phone, Excited to see how big she was, and delivery was in a typical double box. No damage outside to the shipping box or product package. But alas’ my joy was short lived when I lifted the top tray.

Yeah thats a factory defect all the way. Sad they missed it and sent it on, but I guess it happens to them all, also doesn't help that their fuselages on most all their planes are hollow construction. Like in the flexjet, there's pockets between the outer fuselage and the intake and thrust tubes

[F22trainer]

Yeah thats a factory defect all the way. Sad they missed it and sent it on, but I guess it happens to them all, also doesn't help that their fuselages on most all their planes are hollow construction. Like in the flexjet, there's pockets between the outer fuselage and the intake and thrust tubes

I’ll be looking to add some fiberglass reinforcement in any weak areas. You keep me posted so I have time to fire up the smoker and charge some batteries

[rifleman_btx]

Absolutely, will do!

[F22trainer]

Yeah thats a factory defect all the way. Sad they missed it and sent it on, but I guess it happens to them all, also doesn't help that their fuselages on most all their planes are hollow construction. Like in the flexjet, there's pockets between the outer fuselage and the intake and thrust tubes

finally managed to get some time and start on this. Isn’t the motor and ESC usually connected? It wasn’t and it was the ESC that had been shoved in so hard it tore the foam as you see - from the inside. Only reason I opened up the motor hatch was to pull the thing out anyway, so not really a factor but I noticed there is nothing in the manual about making up the connections, which I found out is next to impossible.
The 90mm Viper fan and motor unit don’t exactly drop in, but I’m getting through it and making some motor extensions, since no one seems to sell 12 AWG. I’m replacing the 100 amp ESC with the Freewing 130 amp.
The Aura 8 will be coming out also, in favor of Spektrum AS3X.
Doing some homework on the gear components and electronics as well.
Of course all of this makes to Minwax Polycryllic coverage much easier.

[rifleman_btx]

Oh absolutely, I just did a freewing 9blade in mine, that was enough to really wake it up.

[xviper]

finally managed to get some time and start on this. Isn’t the motor and ESC usually connected? It wasn’t and it was the ESC that had been shoved in so hard it tore the foam as you see - from the inside. Only reason I opened up the motor hatch was to pull the thing out anyway, so not really a factor but I noticed there is nothing in the manual about making up the connections, which I found out is next to impossible.
The 90mm Viper fan and motor unit don’t exactly drop in, but I’m getting through it and making some motor extensions, since no one seems to sell 12 AWG. I’m replacing the 100 amp ESC with the Freewing 130 amp.
The Aura 8 will be coming out also, in favor of Spektrum AS3X.

I can't remember exactly at this point, but I think when I first opened up my F-100, motor and ESC was connected. I also replaced the stock fan with the one from the Viper 90. Yes, as you say, it didn't quite fit, but with a little foam shaving and compression, it went in. I also replaced the ESC with an Avian because I wanted reverse. Although on the surface, this Flex F-100 looks really nice, but are some really "off" things about it. Like the antiquated fan/ESC they use - very similar to the old Taft ViperJet. Then there's the "hollow" innards and very hard to reach servo rod connections. Ailerons that when deflected to the high throw, hits the one bomb and bends the fins. The gear has to be cycled at least once before they work. Paint looks nice but scrapes off easily if not sealed. That thrust tube is so old school. When I put in the much more powerful Viper 90 fan, the thrust tube collapsed in on itself at high throttle (bournoulli principle - sp?). I had to shop Amazon to get some really thick gauge plastic sheets to correct that problem. I have several Flex products and each one has its own idiosyncracies that belies Flex's supposedly high standards.

[F22trainer]

I can't remember exactly at this point, but I think when I first opened up my F-100, motor and ESC was connected. I also replaced the stock fan with the one from the Viper 90. Yes, as you say, it didn't quite fit, but with a little foam shaving and compression, it went in. I also replaced the ESC with an Avian because I wanted reverse. Although on the surface, this Flex F-100 looks really nice, but are some really "off" things about it. Like the antiquated fan/ESC they use - very similar to the old Taft ViperJet. Then there's the "hollow" innards and very hard to reach servo rod connections. Ailerons that when deflected to the high throw, hits the one bomb and bends the fins. The gear has to be cycled at least once before they work. Paint looks nice but scrapes off easily if not sealed. That thrust tube is so old school. When I put in the much more powerful Viper 90 fan, the thrust tube collapsed in on itself at high throttle (bournoulli principle - sp?). I had to shop Amazon to get some really thick gauge plastic sheets to correct that problem. I have several Flex products and each one has its own idiosyncracies that belies Flex's supposedly high standards.

The fan cylinder had Taft Hobbies molded in raised letters, lol! I was aware most of the information pointed to weak QC, and it is noticeable. Nowhere near the quality of FW or others. But I really wanted the airframe and just decided I would go for it and planned on doing the upgrades right out of the box. Kinda fun actually. Even the cosmetics like the overspray and minor decal lifting can all be resolved with some effort.
I may swap out gear and sequencer also. That said, who has a recipe for the silver color?
Buellar?
Anyone?