NikolayTT

Hi Fellows,

Having in mind that the energy stored in the same weight Methanol(or Gasoline) is about 800 times more
than the energy in same weight LiIon battery (measured in Watts/kg) I wander what is really the catch
of making F3A electric. Of course efficeincy of 3-phase motors is nearly 90% while combustion ones
have barely 20% etc, but still... even 80 times more energy packed in liquid fuel makes clear choice
when comes to real aviation....of course those numbers are quite rounded...
Surely, this question might have been discussed number of times; then please point the best
links to read; alternatively, please mention your own reasons to go Electric in F3A and also
tell if you are really satisified for the extra money you pay when go electric ...

Thanks,

Nick

Walt Thyng

My Feedback: (9)

You have asked a version of the old which is better "Piper or Cessna"? The only real answer is a question "which one floats your boat?" I have flown electric exclusively since 1992 because I enjoyed the challenge of learning the new technology and being "different." I continue for much the same reasons -except that now there's a community of e-fliers in my club.

You are going to get a gazillion responses most of them based on the "figures don't lie, but liars can figure" principle or else they will be (like mine) entirely subjective.

Walt

woodie

Walt pretty much nailed it. If you like glo, fly glo, if you like electric, fly electric. If you like both then you may be 'confused'. There are advantages and disadvantages to both. Your fuel energy density example is not applicable since either glo or electric has more than enough energy to accomplish what we want.

A simple search will find more threads than you will want to completely lead about 'which is better'. You'll see arguments about start up costs, per flight costs, maintenance costs, etc, etc, etc...... Happy reading

Woodie

NikolayTT

If I might disagree Piper and Cessna are almost the same "thing" from Technical and Financial reasons, while
Electric and Glow are too different to be purely personal emotion choice when we make choices.

Surely the personal preferences are not my goal to resolve; I was asking for purely Technical and Cost Reasons
being combined and free of emotions indeed. I believe that should be possible to be cool minded even if all we
have our "hot" hobby preferences. Example: I like drivng my sporty car but I am sure I would be not less
successful and even happy with an ordinary one, and with less tickets for overspeeding the life is not worse.
I hope now is more clear the goal my stating question.

Your turn guys, if you can be cool minded when you talk about hobby.

Cheers, Nick.

tIANci

Nick ... its not that cheap to go EP, purchase of batts are like buying fuel up front. Then when the batt goes bad, it sometimes does, you pour all the fuel down the drain. With the rising cot of fuel here and availability of decent really cheap batts from HobbyCity, I am more than happy to go EP. Like many I enjoy the fact there is no need to tune, no grime (I am lazy), no killer vibration. Generally, in EP you can configure for how you like it ... more thrust, more speed etc. You got different motor KV, you can play with battery configuration, assuming you are not talking about 2M planes.

p/s no dead stick. I seen that kill people in competitions.

NikolayTT

Thanks Tianci. Couple good conclusions I will derive for myself immediately. Surely batteries will go cheaper and the other very important thing to mention seems to me the vibrartions, which might permit lighter construction of the plane, and of course the mentioned number of possibilities for enginnering compormise with KV-vs-Propeller-etc. Anyway, I am concerned about F3A because that is a very demanding class and while almost any other RC plave could fly electric, F3A needs lot more than emotions to get it developed right indeed. Still I wander if someone in F3A could give real comparative numbers about his real experience. [sm=wink_smile.gif]

rcpattern

My Feedback: (45)

Nikolay,

At this moment it truly is a personal preference. Both have setups that are totally competitive on the world stage as seen by the results at the world championships. There are cheaper ways to do both that work, but may not be quite as powerful. I personally fly glow, but I certainly don't think people are held back in anyway by flying electric. They both work, and they both work very well. If you are starting from scratch the costs are even competitive. If you have been flying glow and switch or visa versa then you may find the costs to be a little high as you have already previously invested in your current setup. There are advantages and disadvantages both ways. As I said, I personally fly YS, but it is a choice just like many others. As you can see in my signature I am a YS team pilot, however if I truly believed electric was better then I would fly electric as I want the best equipment which gives me the best chance to win. I love my YS engines, but you will find many who will say the exact statements about electric. I have flown competitive electric setups and they flew very well and I know that I could be competitive with the electric setup as well. Bottom line is they both work, and they both work well. Neither are truly plug and play with 0 problems, but as with any high performance setup this is to be expected. I have seen people reference "no deadsticks" with electric, but I have seen several rounds lost due to faulty speed controllers, motors or other issues. The possibility of problems still exists with both.

Arch

tIANci

Arch ... a question, since you fly competitively. How do you find the power to weight ratio between EP and GP nowadays. Is it about the same or ... and do EP planes fly the same as GP?

perttime

I am not a pattern flyer but heres my 2 cents:
- do you have goals (win them all)? Fly because you enjoy it? Do you need to look for the ultimate in performance?
- are you using glow or electric now, or comfortable with both?

*** I am pretty comfortable with electric but glow stuff makes me a bit nervous. That would be reason enough for me to stay with electric. The same might work the other way too. ***

rcpattern

My Feedback: (45)

Electrics have now reached performance levels that are equal to glow. With the power systems available and multitude of props available you can get a very similar feel. I talked to QQ this winter about this and he said he was able to get an almost identical feel flying electric now and because of his job change he had an electric only flying field that he could easily slip out to during the day and get a few flights in. Otherwise he would drive after work and with his kids getting older he wanted to spend more time at home. He said at that time he truly felt that the electrics were now on an equal playing field to glow. They still have some limitations such as shorter flight times and such, but from a competitive standpoint to just put up a competition flight they are equal now.

Arch

NikolayTT

Thanks a lot Arch !

To add one more point is maybe to mention the WEATHER. Depending on the location the Variations in
Temperature might be severe trough the year. While NiCd seems better than LiIon and NiMH in this sense
they have not so much stored energy as LiIon...

So should someone prefer Electric F3A for the Winter or get heavily "dopped" Nitro fuel for GP instead ?

Then the question asked by Tianci holds nicely:
- What is the power-to-weight Ratio in case of F3A in EP and GP and that I guess leads to technically
related question about the Propeller parameters ?

Nick

woodie

I don't think winter vs summer is much of a consideration. If it is cold enough, you have to provide some heat to either system to get it to run right. Batteries can be warmed prior to flight, glo engines can be warmed by various methods to get them to the point they will start.

At the age I am at, anything below 50F is meaningless anyway as far as flying models outdoors... ;-)

Woodie

OhD

Nick,

Your criteria for comparing is too limited. You sure wouldn't choose gasoline power for many of your shop power tools based on watts per pound. Pattern planes are right at a point there it is not a clear choice but electric is gaining fast. Start looking at time flying vs. time screwing around.

Jim O

Silent-AV8R

What I like about electric power:
Very low vibration - servos/electronics/airframes last much longer. Even battery drain is lower due to not fighting vibration.
No mess to clean up
No need to worry about fuel proofing anything
No worries about starting, idle adjustment, etc.
Generally fewer "Flame Outs" if you do lose power it means something has gone very wrong.
No fuel to buy, store, transport & no glow plug battery and starter/battery to mess with.

What I do not like:
Cost, although getting better with cheaper packs available now. With electric you are buying all your fuel up front all at once.
Charging lots of batteries. Sort of a pain, but you get used to it.

For me the pros outweigh the cons.

tIANci

Silent-AV8R ... con side, not to forget a good pair of chargers and a good transformer. I seen some flyers who use smaller servos on 2M planes because there is less vibration. Neer realised that vibration can even kill a servo, smaller planes up to 110 size were never an issue for servos, or so I thought.

NikolayTT

Thanks Guys !

Among the very interesting answers I would mention the most impressive one is what is written
in the signaure of Silent-AV8R: "Reality is Subjective." And it seems so far we did not get anyone
here telling that he has flown so Many Hours at the Cost of xyz-dollars more than the cost of the
other approach. Of course I hope that someone was doing this simple Math:
GPcost= EquipmentCost/HoursFlights and similarily EPcost= EquipmentCost/HoursFlight
And in fact this measure (GPcost vs. EPcost) would be subjective and exposed to market development.

Surely sort of summary at this point comes from OhD: "Pattern planes are right at a point
there it is not a clear choice but electric is gaining fast. "

Frankly, I believe that Electric F3A will gain gradually over the GP when the Electric Cars get
on the roads some visible presence. Just to mention here Silent-AV8R's comment which also
came from Tianci: "With electric you are buying all your fuel up front all at once."

But the PROBLEM is that one cannot be sure How-Much "fuel" he purchased because
it seems there isn't any handy Method so far to know how long Battery life is going to
be especially under the Huge Currents needed for performance of F3A, isn't it ?

Or, is there some method & instrumentation to predict the Battery Capacity
Wearing-off, i.e. so called "State-of-Health" at the first couple charge-discharge
cycles ?

Nick

matt13

I have recently started to fly electric, I still have my YS160, which is already starting to be "dated", but is still an amazing motor.
But electrics ARE already starting to over take glow in F3A. I just liked the idear of being able to fly at my field in summer EARLY, but here was the catch, there is a curfew until 0900, and 1000 on Sunday's! Electric is allowed to fly before the curfew, so I now have an Angle 50 for practice, and LOVE how easy it is to duck out to grab a few "quick" flights inbetween doing other stuff at home, it really is quicker the set-up, fly, then pack up again.
The other advantage I think electric has over glow, if my YS goes "off song", it is a real effort to pull it appart, and get it back together, electric is more what I would say, "plug & play", like another post said, if it is not working, it needs to be swapped, yes you can pull appart the motors, but it is rare. Just my two cents worth. Matt

tIANci

Nick ... the internal resistance of the battery cell ... once its dying, the resistance goes up. I think perhaps at the end of the day, it boils down to preference. We will make all sorts of ways to justify what we like.

john agnew

Nick

To try to answer you question on relative costs I have just bought my first F3A model for electric power, as the airframe costs are the same for both I will address the relative costs of the power train.

Electric :Axi motor £165, Jeti spin 99 £180, 6 x Rhino 5S 4900 20C lipo £300, Cellpro 10S charger £125, power supply £40, total £810.

Glow: YS 170 DZ inc YS mount £600, Hatori header / pipe £130, total £730.

As you can see initial costs are comparable excluding fuel, however if I assume 100 cycles from my lipos that is 300 flights pre-paid, fuel for 300 flights would be around 10 flights per gallon at £25 per gallon = £750.

If you accept these figures electric is cheaper to operate than glow after the initial investment and the charger / power supply are not exclusive to one model.

regards

John

schroedm

My Feedback: (1)

John,

Glad I went electric now when you put it like that

AmericanSpectre505

I am flying both at the moment YS170 and a Pletty 30-10 EVO,..........it just comes down to your flying style and your expectations. I am favoring the EP, as the performance is there. I like the YS170 as it's just a "BEAST" with "CRAZY" power when you want it and very reliable. (pretty much what everyone else has said already)

So, for me it comes down to which one do I score better with, at the moment the YS170, but I only have about 20 flights on the EP...time will tell.


Bill Holsten

Walt Thyng

My Feedback: (9)

Nick, your retort was dead on Piper and Cessna are essentially the same thing; the major difference being low wing versus high wing. Both can accomplish the same mission with slight differences differences in downward visibility, ease of entrance, carb heat management plus one or two other "minor" things. That being said the debate at any gathering of pilots as to which is best goes on endlessly - just like the debate over ep vs gp.
Walt

NikolayTT

Thanks again and especially for what I got as the numbers from John Agnew !

This is a very convincing answer ! Although I wander if those batteries will reach
100 cycles, anyway the very solid saving from "fuel" is there present well.

Frankly, I thought is the other way arround, but John's calculations are solid !

If and when I am going Electric is another question having in mind that I like the sound and
the smell of the GP fuel for more than 15 years altogether RC flying. And on top of the whole
mix of pros and cons I need to confess, I am pretty well decorated as a radioelectronics
engineer... Well, all we are emotional when it comes to RC hobby and thus the Numbers
like those from John are clear answer to all emotions. It seems that if F3A has gone so
deeply furnished by EP solutions, then the EP dominance in the less demanding classes
is pretty soon taking place. Well, I still have a bunch of very good GP enignes with
althogehter resourse of maybe couple hundreds of hours; maybe I should consider
getting some of them into eBay...

Surely the discussions in RCU are great and I am very thankfull for all constructive
answers !!!

Nick

Scott Smith

My Feedback: (4)

Some numbers...

I've flown 870 flights in the last three years. My original TP 5000's have between 130 and 225 flights and I still fly them regularly. I figure I'm at $2.17 per flight with those packs. I picked up 4 new 5300's at the start of this year. With that investment, I'm at $3.45 per flight….but I have all the fuel I need for next year!

dreadnaut

My Feedback: (5)

One more pro. (actually a con of gas). I live in an area where flying fields are drying up fast. I have resorted to flying off the local college parking lot on the weekends that I don't feel like driving 40 miles. If I flew glow powered there, I would get chased off quick. I plan to start flying pattern again this upcoming season with an 8s setup. I haven't tried my local spot with anything that large yet, and may have to use an alternate (15 mile round trip). Still, electric gives me more options.