FLEXJET SUPER PNP

[xviper]

Usually, when they go from 6s to 8s, the designers reduce the kv if they plan to use the same fan because of the possibility of overdriving the fan where it begins to lose efficiency (cavitation?). But since the kv is within 50kv, I can see the thrust being much higher so long as the fan speed doesn’t go beyond its efficient max speed. I don’t know the real terms to use so that’s the best way I can put it.

[Phantom]

Sounds to me as long as I don't have fan failure, it should increase the thrust significantly.

[Robert Belluomini]

Just priced the TV upgraded power system, comes in north of 300 bucks before shipping.

Id buy a Schuebeler DS51 for that kind of money

[Robert Belluomini]

XViper when I first started flying the FJet I too found it twitchy and not to my liking. It was suggested I load the Expert configuration and found it actually made the model fly much smoother.
Re: the Aura 8 it is one of the best flying gyros
i have ever used. The configuration tool has numerous presets for any model type. A serial connection is the best way to utilize all these functions. my rx have a serial connection std.

[Phantom]

Id buy a Schuebeler DS51 for that kind of money

Just priced it, with a 1400kv motor, (closest kv motor to the flexjet for a fair comparison), it comes in at 440 bucks.

[xviper]

XViper when I first started flying the FJet I too found it twitchy and not to my liking. It was suggested I load the Expert configuration and found it actually made the model fly much smoother.
Re: the Aura 8 it is one of the best flying gyros
i have ever used. The configuration tool has numerous presets for any model type. A serial connection is the best way to utilize all these functions. my rx have a serial connection std.

Once I lowered the rates and increased the expo, the jet was fine. With flaperons, it was even better.
The Aura 8 is no doubt, state of the art, but I found it's just too complex for my simple mind and too fiddly, having to connect it to a computer to do any programming. Plus, the serial receivers aren't cheap, although had I purchased them, I could have done what I wanted. Like my old Thunder Tiger Innovator MD 500 helicopter that needed to be plugged into a computer, these things are just "ahead of my time".
If I understand correctly, that price is for just the motor and fan (DS51)?. The FlexJet is not cheap to begin with when compared to other of today's popular EDFs, so to add another $440.00 to it, seems to me to be a bit excessive for what you end up with. I got bored with my FlexJet after only a 1/2 dozen flights. I can't say that about most of my Freewing jets.

[xviper]

Sounds to me as long as I don't have fan failure, it should increase the thrust significantly.

Failure in a fan will be more dependent upon balance. Where a water impeller can destroy itself through cavitation, the air equivalent of cavitation would be like beginning to pull a vacuum and as such, shouldn't be as dangerous if the fan is properly balanced. In such applications, I believe it's important to precisely balance the fan assembly before its first use.

[Robert Belluomini]

Just priced it, with a 1400kv motor, (closest kv motor to the flexjet for a fair comparison), it comes in at 440 bucks.

It was 390 with VAT which is 21% so once you remove that it’s around €308 not sure what’s the currency exchange is right now To US dollars but that 440 sounds really high

[Phantom]

I googled the exchange rate and it came in at 439. And some change. I selected the motor and fan already be assembled, perhaps you can save a few bucks, assembling it yourself.

[Robert Belluomini]

VAT is 19% so after removing that and doing the exchange it comes to $355.00 USD plus shipping

[Phantom]

VAT is 19% so after removing that and doing the exchange it comes to $355.00 USD plus shipping

Robert, you were correct. Subtract the VAT and it comes to $355.73. However for worldwide shipping via DHL economy world, outside of Deutschland/Europe is another $66.35 for a total price tag of $422.08. I am familiar with HET motors, but not with Schuebeler fans, is the juice worth the squeeze?

[SPUD 37]

Her's my newly finished Flexjet. My Avanti met an early end when it augured in on it's maiden flight. Pilot error, I believe I had the ail. going the wrong way on the gyro. Oh well. I have a bunch of Flex planes so I thought I'd add the jet. Raining here in Fl. so won't get to fly it for a couple of days.

[xviper]

For what it's worth, here's a video of my flight from this morning. Just to recap, I've pulled the Aura8 and am using a Lemon RX, with no stabilizer. I simply didn't like the Aura8 the way I had it configured (no sat RX), even after I reprogrammed the flight modes. What you see in this video is my FlexJet with flaperons. I landed with full flaps and that resulted in a somewhat ugly landing (second flight was very bouncy, also on full flaps). My third flight was with 1/2 flaps and it was "perfect". As you can see, I didn't think this plane could push it's way out of the thick grass but it did actually get off the ground in a fairly reasonable distance. It has very high lift wings. I haven't flown it in about a year and since then, I've acquired several other jets since - FW L-39, ME 262, FW SU-35, FW F/A 18 RAAF. Now the FlexJet feels slow and a bit "normal" and uninspiring. It still flies nice and sounds real good when it goes by. The quality is undeniable but looking back, the price was obtrusive and the bang for the buck is NOT there. Nevertheless, it's still a very fine platform to carry Mario around. It looks real pretty hanging from my garage ceiling.

[Chkwoot]

I’m wondering I have a grassy short runway, is it possible to use mode 3 to takeoff quickly without any issues based on your experience?

[xviper]

I’m wondering I have a grassy short runway, is it possible to use mode 3 to takeoff quickly without any issues based on your experience?

You can see from my video above how much distance it takes to get off very thick grass. If your grass is mowed, it'll build up speed much faster and get off the ground sooner. You can also see how much ground it took after landing for it to stop. Just to clarify what you mean by "mode 3", are you talking about the stock Aura 8 programming? Mode 3 would translate into very high rates and more expo, correct? I don't use the Aura 8, but what you saw in that video, I'm using an equivalent high rate on the elevator to make it rotate better. If that grass was mowed shorter, it could have lifted off in 2/3 that distance. I've done it at another field with much shorter grass.
The current version with thrust vectoring should be able to get off the ground in even shorter distance.

[Desertlakeflying]

And then there is the big turbine version.

https://pacificrcjets.com/collections/t-one-models/products/t-one-models-t-50?variant=18286824226912

[I-fly-rc-aircraft]

Thought the Flex Jet could use a trim change.

[EDF_Lover]

I can’t tell how active the FlexJet topic is, but I just bought one and I’ll take any advice you guys are willing to provide!

I maidened it yesterday and it didn’t go well. I used a 5200 mah graphene battery, positioned for neutral CG.

I fly off of grass, that had just been cut, and used the “basic” (versus expert) Mode 1. It took a long roll to get airborne, but was completely controllable once it was off the ground.

I left the gear down for a couple of times around the pattern and it only needed about 3-4 clicks of up trim on the stab to fly level. It was a little twitchy in 5 knot winds. I raised the gear and no trim was required to maintain level flight. I switched to Mode 2 and it became rock solid with no real changes in control response. All great so far.

After 3 minutes of rectangles, I set up for a landing approach. Getting into high alpha was easy and stable. I touched down mid-way down the field.

What happened next was was very quick and ugly. Here is the sequence, which I’ve reconstructed from all the evidence.

The front gear door had opened but the nose gear hadn’t come down. I missed this - I think because the mains are so big and visible that the nose gear gets lost a little behind the gear door (landing left to right had the door facing me). I was also paying most attention to attitude and airspeed.

When the nose came down, the door snagged on the grass and ripped out the gear door servo, flattening the door. This allowed the nose to drop further. Which caused the right main retract “knee” to hit the grass and rip cleanly out. There was very little foam on the mounting tray, which remained attached to the retract. The wire remained attached, causing the gear unit to swing back and into the fuselage, puncturing the foam (which is thin at that point) into the motor compartment. It then separated from the wire and hit the stab, which is now dented and some tape that covers what looks like a weight shattered.

I have contacted FlexInnovations support and they have asked for pictures. Hopefully I’ll get some help with the parts I need. I fly EDF jets a lot, and I’ve practiced the high alpha landing a lot (esp. with my Freewing F-35 V3). I don’t always land perfectly, but I know what a good approach and touchdown looks like. And, this one was good enough that I don’t think it should have hurt the jet at all.

That said, the right retract tray separated very cleanly from the foam - so perhaps that was a failure waiting to happen too.

Had anyone seen glue glue issues with this model? Are there areas I should be reinforcing?

Thanks...

[I-fly-rc-aircraft]

I've re-glued both the mains on mine but I fell they were adequately glued in at the factory, it just happened on poor landings. I am however on my third nose retract. It wasn't dependable and I had to land with the nose gear up but I managed to keep the nose up until almost stopped which resulted in just some minor damage to the belly and front gear door.
I make a habit of doing a dirty pass prior to landing just to be sure all wheels are down.

Tom

[xviper]

My last flight with this plane ended badly. It rolled on landing and didn't want to slow down. It hit the grass at the end of the GeoTex runway very fast. The grass is much higher than the runway surface. When it hit, the plane broke in two, right at the where the leading edge of the wing meets the fuse. The front retract broke off complete with all the balsa it was attached to. I may or may not fix it. The parts are quite good and they may serve a better purpose in a different plane. Prior to this, all retracts have come out at least once but was easy to glue back in. One must remember to cycle the gear a couple of times before sending it up. It needs to "wake up" (initialize).
EDF_Lover, if you had a power glitch while in the air, the gear may not have "awakened" again. I also found "mode 1" to be very twitchy because (if I recall correctly) it has no stabilizer or very little stabilizer programmed in. Mode 2 and 3 are more stabilized but also have higher rates. I tried the plane with the Aura 8 programmed with stabilizer on all 3 modes and even increased the stabilization throughout. I started flying this off grass and I found using mode 3 got the plane off the ground much more effectively, but I still didn't like the way it flew and took the Aura 8 out, opting to use a "regular" receiver exclusively. It flew OK for me after that. At the time, the FlexJet was an exciting concept in design and appearance, but having flown it for a while, I find the execution of it to be severely lacking and the price point unjustified compared to what was out there at the time and what has come along since. The landing gear is wonderful but they simply aren't secured on the plane adequately.