F22 for grass ops

[Gsky]

Hi guys,

ive been wanting the FW 90mm f22 for a while but been a bit concerned about our grass runway. It’s long enough to take off the FW 80mm L39 but only just! And grass can get a bit long in summer between mowing days.

I’ve heard some people mention a fan upgrade has helped with takeoff distance. Don’t care much about top speed but nice to hit ~100mph

Thinking the 6s for weight with 5000ma + 130a spectrum esc. But could do 8s if capable of shorter takeoff

But can’t make my mind up on fan/motor.

FW 12blade 1835kv
fms 1850kv
fms 1950kv - from eflite 90mm viper
Schübeler 2100kv - very nice engineering but pricy.

Any thoughts?

thanks!

[rifleman_btx]

I've been running mine on grass with the original motor 6s for a couple years now no issues at all.

[Evan D]

F22 and grass are not a problem.

[Gsky]

Ok good news so far. I guess the question is can the FW f22 have a shorter take off than the L39?

[Evan D]

About the same...

[Gsky]

Ok thanks for the reply. I think it would be worth have some extra power than to take off on our short runway as the l39 only just takes off and don’t want to risk running into the crops at the of our strip (done once when the grass was damp)

any thoughts on a good upgrade for extra takeoff thrust to be safe?

[Evan D]

The F-22 has less apparent power but much lighter wing loading to make up for it.

[rifleman_btx]

I thought I had video of my 22 in flight. I installed the 9 blade inrunner. The performance is right where it needs to be on the batteries I fly.

[Gsky]

Ok so a FW 12 blade 1835kv or fms 12 blade 1850kv wouldn’t help to reduce take off distance over the stock FW 9 blade 1900kv edf unit?

[xviper]

Ok so a FW 12 blade 1835kv or fms 12 blade 1850kv wouldn’t help to reduce take off distance over the stock FW 9 blade 1900kv edf unit?

Have you thought about going 8s?

[Gsky]

Yea I could go 8s. Wants sure if that would be better than 6s in terms of takeoff distance due to weight. Was thinking a high static thrust low weight setup would be best

[xviper]

Yea I could go 8s. Wants sure if that would be better than 6s in terms of takeoff distance due to weight. Was thinking a high static thrust low weight setup would be best

This is what I thought with regards to the 90mm Yak 130. A friend had one and he had the stock inrunner Freewing EDF in it. On grass, the plane barely got off the runway before hitting the weeds at the end. In fact, one day, it looked like it wasn't going to lift off in time and he yanked on the elevator and it leapt into the air without sufficient airspeed and tip stalled into a tree. After fixing, on a smooth runway, it took up >3/4 of our runway to lift off. When I got mine, I went straight to 8s and on the same runway, it lifts off in less than 1/2 the runway. The plane may not fly much faster than the 6s version, but it has so much more "grunt" for take off and it flies with more authority and confidence.
Check out the static thrust of the 8s fan and compare to that of the 6s fan you are looking at. Published static thrust may not mean much compared to when the fan is in the plane but the numbers are enlightening within the same testing parameters.
I'm looking at getting the F-22 for next spring (if there's any stock for the ARFs when I'm ready) and putting in the 8s fan and thrust reverse. You likely don't need thrust reverse for grass ops but it's an amazing thing for smooth surfaces. Both the F-22 and Yak-130 weigh about the same with battery on board, although I believe the F-22 floats better, so it likely lifts off better than the big Yak.

[rifleman_btx]

Mine lifts off in 120ft

[Gsky]

Thanks rifleman_btx, 120ft take off sounds perfect.

xviper, i did some comparisons of 8s and 6s edfs. looking at the stats (from rc castle/turbine rc) looks like the 8s would be a decent static thrust for weight upgrade. Does look like the stock 6s 9 blade inrunner is one of the best 6s fans for static thrust. im leaning towards the stock 6s setup for now.

[xviper]

You can always change later if the need or the urge arises.

[Gsky]

Yea, would love the schubeler unit but figures don’t look that much difference from stock for the extra money

[Evan D]

We all have decide where to draw the line. For me Jet Fan with a HET motor is a great balance. You also have to decide what batteries will work for each situation and what ESC to go with. Selling unused parts can help offset a lot of the cost especially if you pull them and sell them as new.

[Gsky]

Went for the stock 6s will see how she does

[GliderGuy]

deleted cross postings

[xviper]

Is this a symptom of 5G? Are we going to start seeing loss of control events when flying near cell towers, now? Thoughts/Comments? Have any of you seen this?

-GG

Not with cell towers but then, this new 5G stuff is supposed to be much higher energy. We've seen the aviation industry voicing concerns about these towers being close to airports. As a result, the big cell service providers have said they would postpone firing up their 5G towers when they are close to airports. I've heard no updates on this for about a week or so. The ones not near airports were apparently activated last Wednesday.
What I have seen at one field is a "dead zone" at a fairly distinct distance from our pilot stations in a very distinct vector toward an electrical power line. The distance is about 300 - 500 feet and the dead zone has an angle of about 10 degrees and goes from almost ground level to about 30 degrees above horizon. If the plane is flown across the dead zone, it has enough momentum to get through it. If it goes more along the dead zone, it usually results in a crash. In the dead zone, there is no response to stick inputs. We try to stay away from that area or if we're caught that far out, we try to fly across it as directly as possible.