Official Freewing 90mm F-16 V2 EDF Jet Thread

[Airguardian]

+1
Very rare around here though.

[urrl]

Markham Park has lakes and canals near the airfield so that could be why there is almost always ground fog early mornings. Love it.😊

[Airguardian]

Lucky you!

[f4u ausie]

Hey guys hope U all well now the Nitty gritty.. my friend and I. Have now bought a machine to do change or adjust the ESC timing. A good thing. Mmm anyway I did the beep thing couple years ago with X vipers help. He sorted my problem so is. changing timing from factory settings. An advantage.. or r factory freewing settings generally good. I guess this applies to all. Or most 70 to 90 mm jets. What may. Be a reason to change timing . A different thread may have been order of th day... But this is it. Thanx in advance Craig

[xviper]

Timing change can be a tricky business. In general, increasing timing on EDFs may give a slight bump in power delivery at the expense of higher fuel consumption. I see it akin to timing on cars when we used to use timing lights and adjusting the distributor position (degrees advance or retard). For high performance engines, one could get an increase in output (with an increase in advance timing), giving the car a bit more get up and go, but if you kept the change over a period of time, you would notice it sucked more fuel. Keep increasing it and you eventually arrive at a point where the engine begins to stumble and hesitate. This is not entirely different from increasing gain on an RC airplane. Increase gain a bit too much and you get oscillation as speed increases, then you have to back it off. With a car, we used to have other parameters that could be adjusted to go along with timing to make it all run "better", such as, carb sizes, intake and exhaust tuning. On our planes, there is little else that is readily changeable to help accommodate timing changes, maybe bigger ESC (like large fuel line), more mah (like bigger gas tank) higher C (like stronger fuel pump), higher voltage (better fuel/additives).

For your EDF, try going to the next step up in timing and see how you like it. Reduce your flight time a little so you don't run out of battery and have to dead stick it in. Check battery usage at the end of the flight and compare with previous flights at the old (default) timing. Usually, default timing is more than adequate for how most people fly. If you look at the ESC's manual under the timing line, you will see (*) to show what the default setting is. You can try the next higher one and see what that does for you. Do a couple of ground runs up and down the runway (but don't take off) and if you notice and oddity in the way the EDF sounds, then put it back to default. Timing on these things usually are: low, medium, high, with some ESCs giving one other level thrown in there. Most of us will likely not feel or notice much difference.

Other opinion may vary.

[Evan D]

Craig, what planes and set ups? Absolutely put a watt meter on anything first and after any changes. Many of the current FreeWing jets are at or even well over the rated amperage of the ESC in it. My 80mm's are 105-125A out of the box with a 100A. My 8S 90's are 115-125A on a 125A ESC. These are all on standard voltage batteries. HV are significantly more,

[f4u ausie]

As always great info guys. The car analogy good!!! Evan at this stage it's regarding V2 F16.. we both have 8s. Think I will leave mine alone.. having enuf trouble landing it(compared to f4 phantom easy). My friend is retired so has more time to experiment .. but we r having a blast and do Wana get better thanx again

[xviper]

Mine is also 8S. I fly it as it came. I can slow it down by opening up the speed brakes on final and getting into a nose high attitude about 100' from the apron. Then regulate the throttle so it doesn't fall too fast while keeping the nose high-ish. 8S, for me, tends to have plenty of poop and when I want a little more, I just use HV bats. The difference is noticeable but not enough to make me get more HV batteries. Today's newer batteries, even the lesser known ones seem to work quite well in my jets, even though the high "C" ratings are very much exaggerated.

[f4u ausie]

Think I had to much elevator 8 mm more than high factory... Did that when on 6s. To pop it off the grass. 8 s gets off easily have reduced. Will try nose high bit further out.

[Evan D]

Where's your balance? About 25mm behind the factory CG is about right.

[f4u ausie]

Oh wow. Mine is now 10 mm. Bhind Should I b nervous.. maybe sneek back to25 or just go to it. It has a plus as3x in it

[Evan D]

I don't have a gyro in mine at that point.

[f4u ausie]

Ok thanx

[Airguardian]

What xviper said.

Years ago, in the age of sh*tty low-blade-count EDFs, I used to default to high timing to give my birds a bit more oomph.

Nowadays, with the stock 9-12 blade setups most of us run, increasing timing is borderline suicidal. On something like a twin 70mm (Say, Freewing Su-35), going to high timing on modern EDFs can result in 160-180A current peaks if you are using good lipos.
Get ready to smoke them in a heartbeat and get 2-3min flight times if you aren't careful. Of course, your mileage may vary depending on the particular EDF and setup. The most sensible way to experiment with this is by having some measuring equipment or in-flight telemetry so you can quickly work out the effect of your changes before you get a nasty surprise. Most current-modern 12b EDFs I suspect must be running on medium timing by default... maybe low timing in some cases?

[f4u ausie]

Thanku airgardian

[xviper]

Oh wow. Mine is now 10 mm. Bhind Should I b nervous.. maybe sneek back to25 or just go to it. It has a plus as3x in it

I tend to start mine as close as possible to the published CG and see how it flies. If it flies the way I want it to, I leave it alone. My F-16 is about 10mm back, like yours. I did it because I wanted to be able to more easily get the nose up on final for the landing. This seemed to achieve that so I've left it there. If you like doing high alpha passes as a regular thing, then perhaps going even further back is worth a try but do it a few mm at a time. Even though this doesn't apply in most cases anymore, I'm still haunted by that old saying, "Nose heavy will fly OK. Tail heavy will fly once." Today, we have fancy TXs that can easily give us rates, expo and various mixes that help our planes fly and do things we used to have to do by finger intelligence. Then there are these new fangled gyros that can make many RC models (especially helicopters) operate like "child's play".

[Airguardian]

A tail-heavy setup run by a gyro is not 'child's play'. It will still be twitchy and sensitive. The gyro makes it usable and the aft CG enables crazy maneuverability, but it's a long shot from being 'child's play' ;)

My F-16's CG is about 35-40mm behind the manufacturer recommendation. The jet is beginning to be actually tail heavy at that spot. If I turn the gyro off, the jet becomes almost unflyable. But this way I can maneuver a lot more agile and do things that a normal setup isn't capable off, no matter how much you program on a tx. ;)

[Aros]

I've actually had great success with my 8S version. No gyro, bone stock. I bring mine in much like xviper described in an earlier post. Nose high, manage throttle for altitude, bring her in with brakes. Plops down scale and unceremoniously every time. Even does great fully loaded. Unlike the F-18 which has given me inexplicable problems, this one seems like a sweetheart.

[Airguardian]

The F-18 problems are the result of the lack of working leading edge flaps. LEFs increase the usable sustained-high-alpha range and fix the nasty stall that haunts the airframe, as demonstrated by many people already, who modded the jet with working LEFs ;)

[Elbee]

Airguardian.

Where do suppose I might find a picture of two of said modifications?

Best, LB