I'm not clear on fine points between electric and IC powered stunt ships, but my gut feeling is that going to 70' and 58 MPH is not likely to help in the wind. My assumption is that 70' lines will increase power requirements; in the case of IC powered ships, it generally takes more power to handle longer lines.

I'll be interested in your experiences with long lines. The worse that may happen is you have an extra set of 70' lines to cut back down to 65' or so.

Electric power is already superior to most IC setups, on consistency alone. Developments such as 2-4 break emulation will only improve it.

L.

"The reason so little is done, is generally because so little is attempted." -Samuel Smiles

>>>Not sure where that will lead.<<<

I know - to more fun 

I am with Igor on that one.

Certainly, I have seen all manner of wet setups respond to the load-lightening transient as the airplane transitions into the headwind. They all do the same thing, to a lesser extent usually, as when coming downhill: they go rich or make less torque. We did and still do spend a lot of time making them do that. it is an unfortunate by-product of making a "stunt-run" and I'll bet that Igor can confirm that more than half the experiments to electronically produce a good stunt-run will also have this same unfortunate characteristic. The ones that do not will have the left-handed twin of this problem 
Care to guess?

Dean

It can be overdone ... as everything ... it is question of compromises, you can have perfect speed controll and it can easy mean that the motor will brake when you do not expect it and it will make think difficult to controll

so as I see the thing now, it can olnly little bit help, but cannot solve everything, it is just another element which can be optimized, but it is not something what gives clear and unbeatable advantage

for example it can make 12x6 prop to be competitive with 13x6 ... nothing more ... but I remember competition of LA46 to pa 61 in the same final of WC, so it is still about flying, trimming, practicing ... and "techies" just get another area to have fun :-) ... and those who want to sleep all the life can still fly the same what they had 20 years ago, just instead of fun comming from new stuf, they spend time with little more parcticing to ge the same level

I really love it when you guys talk dirty..  ;->

This is fascinating stuff. I'll know when ECL has solved the problem when the motor
pauses and runs backwards a little for braking effects at just the right time!

L.

PS - Hmmm. let's see, I'll add a microprocessor noticing where I am in the pattern, airspeed
and receiving telemetry data on wind speed and direction, density altitude, and programmed
to behave PRECISELY as it needs to.. 

"One of these days I'm going to cut you into little pieces." -from Pink Floyd's Meddle

Well I can already add a GPS unit to my onboard data recorder. Now if it only had a bit better position resolution, we could dump the data and run my pattern through a computer and voila, no judges needed  ! Also no more arguments on the judging subjectivity (except for the appearance part!). The only issue would be to finally decide what some of the pattern maneuvers (like level flight above a varying terrain) really are, and the out-of-order stuff.

Heck, just get an onboard processor programmed with sensors and actuators, and program it to FLY the pattern,, all you need to do is stand there and spin around,,

In the year 2525,
If man is still alive,
If woman can survive
They may find...   

Meddle? Zager and Evans? I just love it!

Alan so appropriately warns, "I suppose I am a little worried that if we go to far, we will be tarred and feathered by the village folk!"

Well my friends ... been there, done that, I should have a T-shirt made: maybe you don't remember some of the names I was called back in '87 & '88 when the tuned pipe thing was introduced. "baby-killer" might have been preferrable.

later friends!
  Dean

Hey hey, I never called you anything as nice as "baby killer"!

All seriousness, aside, we have technology to get more info about how our systems operate than ever before - and perosnally I think I see people falling in love with the DATA, but falling short of understanding its value.  Its the old "numbers don't lie but lyers use numbers" story.  Personally the only DATA I am interested in is whether I successfully commited aviation, most of the extraneous data is just "noise" in the experiment.

As Igor pointed out, IC or electric: go fly.  Practice means more than reams of data logger stuff.

Hi Guys,

This thread really illustrates why we all keep coming back for more with our single axis toy airplanes. Most of us just get such a kick out of fiddling all the time. I enjoyed the comments of Dennis to Kim D when Kim explained exactly what to go and buy to make a really good electric stunter that will work. It will also save bucks and avoid buying of stuff that "may" not work. These were really good suggestions. but so many of us get a great kick out of trying all kinds of alternative ways, and in this manner we satisfy our enquiring minds.

Dean, if you get called names........so what?? At least you are being noticed, and of course you get a nice warm fuzzy feeling when time proves the point. When I started out on my 3-D simulation thing, and dared to challenge the stunt rules, I was called many things. The best one that I got via e-mail, was the one that said that I must be sniffing too much diesel. It's all in good fun.

On the point of flying in the wind, I always thought that for a simple set-up, the diesel really handles the wind on the downwing accelleration problems, better than most. Electric with a good governor set-up is even better. I was lucky to fly Rob Metkemeijer's Yatsenko Shark with his prototype .77 glow engine at out Nats last month. It is a long-stroke, 6-port AAC design with a rear intake, and was swinging a 14" 3-bladed prop. The weight of this work of art, is around 280 grams. It only used about 90 cc of fuel for the flight, so I guess that it is choke down quite a lot. Our altitude here in Johannesburg South Africa, is close to 6000 ft. ASL. This engine just "growls" through the flight with very little 2/4 break. It did not accelerate much in the gusty weather, but then when I flew it, the wind was reasonable, and not like typical "world champs" weather in Europe.

Rob flew my Electron afterwards as well, and he was most impressed by the power and solid constant speed. He noted that it is a little deceptive when you watch the electric models, because they just don't sound powerful. I remember talking to Peter Germann at the last world champs and he said that the electric models just don't seem to handle the overhead maneuvers well in the wind. He said that it was quite visible to him in fact. Ask Igor, who placed 2nd in some of the worst wind and turbulence that I've seen at world champs, if he had no line tension overhead.

Another guy that I have the greatest respect for, is Gilbert Beringer. He has certainly experimented as much or more than most of us. He also flew many diesels by the way. He told me some years ago, that in good stunt conditions, a 2/4 break system is hard to beat, but in bad turbulence, a constant speed system is much more predictable, and therefore easier to score good points with. He found that 4-strokes gave him a similar performance to diesels.......without the smell. In similar manner, electric motors in governor mode are even better.

I fly my Electron on about 69 foot lines, or just a little under full length. I like the extra "space" for the maneuvers. I have flown my model at 4.7 to 5.2 secs/lap and it is still fine to perform a good pattern. My choice is obviously the slowest that I can get away with, but like the great Windy always says, it's the speed through the maneuvers that is important and not the level flight lap times. I've timed all of the systems in use today, and if you take a top pilot flying a ST 60, 4-banger, or tuned pipe system, they all take a similar time through each maneuver. The 2-stroke glow engine will purr around at a good 4-cycle, and then speed up through the maneuvers.

So, I don't think that the line length is really a problem, within reason anyway. It all comes down to what you are comfortable with. I just don't like trying to get used to different line lengths. Strong, smooth wind is not the real problem. In Landres at the world champs for example, even in lighter wind, the turbulence, especially on the grass field, was horrendous. The great thing about electric, is that you fly faster by setting the rpm accurately (if you have the right governor system), and you can fly a good pattern even at 4.7 secs/lap, because it just doesn't go faster.

I will just note what Keith knows - I had installed test version of 4-2-4 in my model in Landres, but I switched it off (variations less than 100rpm) because of that turbulence, I was not sure if it can handle those terrible conditions well. So I rather set lap time to 5.0 and did the contest on constant rpm without risk. It was quick, but still visibly slower than most IC motors.

I have two different devices, that one which simullates 4-2-4 does exactly what 2C 4-2-4 does. In case of additional load on prop (it has current sensor) just adds little bit on power.

Basically it is a timer, which is programmable by Jeti box (the same box used for programming Jeti Spin ESC) where you can say time and throttle. But it has additional function which liearly adds throttle depending on current. It has also adjustable low pass filter for quick ESC which can lead to oscillations (it is positive feedback).

But you must know that it has also all ill effect of ususal 4-2-4 for example if you fly against the wind, prop unloads and it means that model goes even slower :-)

From my experience - it is works well in calm (it is necessary for indoor models), it can cancel slippage to some extent (means I can fly smaller prop at lower power and smaller battery), but its effect needs to be limited in turbulence - but this is old storry, we know longer time that less is sometimes more and that models with less power sometimes perform better than those strong in turbulence - that is why I used that model in Landres 2008 and in Sebnitz 2002 - I had piped OS MAX LA .46 in Sebnitz with prop 12x4 (placed 10th) and electric powertrain with APC 12x6 (means even less power) in Landres and turbulence was not a big problem (compared to strong .60-.75 wet models sometimes flying at 4.8s/lap)

I will make screen shots in new thread

look to my device with gyro sensor ... so yes, we can, but it has also some ill effects, for example it reduces power in wind just before entering figure, it is also wrong ... so the answer is that yes, we can have any system we want, but atually the most important is to say what we really want and it has to do and when 

and then when we have it, it needs to be set well, more settings = more chances to do it wrong :-) ... we are on begin of the electric era ... we will certainly come to many tricks like we had with IC engines :-)

These pictures were taken at the recent Dutch Nationals. Rob Metkemeijer's stunt engine and the prop. Sounded nice.

There was also another gentleman flying an electric stunter. The speed controller was way back under the wing. Why? He's using line tension to regulate speed!

Iskandar

 
If you fly your plane tethered to a tripod you can have instant variable throttle (and elevator/flap) control by RC!

What more could you want?
 

Ned

Words well spoken.

Jim Moffatt   

You're showing you age Dennis....

Amen Brother!

A sure sign of getting older is when you CANNOT understand the music young folks are listening to... (actually I am kinda proud of that!)

Ned

Words well spoken.

Jim Moffatt  

However, having a servo driven system (including force feedback) with multiple, programmable transfer functions would be the thing to aim for,  of course.   Kim Doherty has shown us where to go...
But for now I'm having my hands full with just making the power train behave 'ideal' (= better than I.C.)