pmmartin

I am not trying to be disagreeable and I hope I am not as bad as your wife :-( . It is just that I really understand what the original post was about. You have had a lot of good guidance to help you and you have become affiliated with companies that have been able to give you good advice. I do know that many of the ARF models that come with a brushed motor in the box or suggest one are underpowered and barley fly. I have two of them here that I could give you. One example is the Micro Whizz. If you go as suggested it will hardly fly and it is very difficult if you can. I have considerably upgraded the power to a larger brushless and it is fine.

If you have an understanding of physics, aerodynamics and electrical power you are all set. Some people are intelligent and interested but have difficulty which I can understand. I was a teacher for many years and know you can't assume anything about someones interest or ability.

Remember you have a very technical background and have engineering experience which makes a big difference. Once one develops an understanding of a particular field of interest it then appears easy.

I have great respect for you and I do not mean to say anything that offends you or anyone else in the forum. I am only interested in trying to solve the same problems that we all are.

Let's make it fun. Fun should be found in participating in whatever aspect of this hobby turns you on. I don't think that any one aspect is better than the other. We all have our own diverse interests and mine happens to be sport flying larger electric models. I can't fly pattern or 3D but I am very happy doing what I do and always have been starting with control line 50 plus years ago.

Many folks find it difficult choosing and setting up an electric model and still have a great interest and desire. Let's all do what we can to make it easier for them. I think that is what this thread is about and I think everyone has been trying. You are right that electrics have gotten many new folks started in the hobby and that is great. There are also those that have purchased poorly and have become discouraged. They can be found here and on Ezone.

I have found a new interest flying in the sunny south and hope to continue for a long time. I can't wait to get back to Florida even though I will miss my granddaughters. (I just said that to make Greg and the working people envious!) I hope no one feels I have gotten too far off topic here. Sorry if I have.

Paul

Greg Covey

Paul,

Ahh yes, a geared Speed 280 on an 18oz [link=http://www2.towerhobbies.com/cgi-bin/wti0001p?&I=LXFZZ5&P=ML]Micro Whizz[/link] from Great Planes. Well, every manufacturer has their failures but they have certainly made up for that black eye by producing some great stuff right out of the box.

I have heard from many long time R/Cers that there was a time when ARFs were crappy and even kit glow planes flew like crap. Fortunately, I entered the hobby at a very exciting time and I feel that the future is here now with the electric revolution.

You had to bring Florida up again, huh? Some day, i'll be there too.

Happy Holidays

jbflier

If there are exceptions,( Park Zone, Hobby Lobby, Tower, Hobby People, etc) that everyone here says work and fly well, why would anyone try/complain about using those that don't? ....

powerchute50

Fine, but how do you match the power to the model? That is my burning question. How do I calculate the power I need for my 72" Stinson? You seem to suggest working out a power system and building a plane around that. I want to do the opposite. Build the plane and then determine the power system.

And if the motor is so inconsequential, why does Hacker make 20 of them? We could have 2 for all purposes. Just gear it for the bigger models. I think the motor counts for a lot more than you suggest. The batteries are just the gas tank.

Everyone in my club will tell you the pitch speed and expected performance of every gas model they own. It is especially common in scratch building to lay out the performance of the model you are designing. Everyone does this. You estimate your intended speed and weight and balance that with required power.

Absolutely true. But again, how do I decide when to gear? Can I take the motor out of the Pico Stick, gear it, and put it in my 1/3 scale Cub? After all, the motor doesn't count, just the batteries.

As for the comments about underpowered ARF's, that is the overall impression at our club. One member bought the A-10 Warthog from GWS and it barely stayed in the air. He changed up to brushless motors at the suggestion of the dealer but he is having a devil of a time balancing the electrical system. It cuts out in mid-flight. Different ESC's and battery packs have not helped. He has dumped it in the closet in disgust. He spent enough on it for 2 decent gas models. There just isn't enough information available from dealers and suppliers if you step outside the factory setup.

I think the Aveox web site and their suggestions are the start of some semblance of order in electric models. Hopefully this will grow and we will be able to compare different manufacturers on a common basis.

StephenT

For a simple electric plane that uses a nice li-po and RTF out of the box, buy a Watt-Age Micro Flyer for only $39.99. Its got ROG's. Nothing complex here. My son showed up at the FF on 2 Sunday's back. Last week everybody had one.

Greg Covey has a review.

StephenT

lwatson

My Feedback: (2)

I have been doing electric flight for about 2 years, and I agree with the original post that we need to make this easier. When I was flying glow we classed based on engine size:

.09
.15
.25
.40
.60

Of course there was a corresponding wing span associated with each. In electric I have come to think of all up weight as determining the class of plane:

10 oz
15 oz
20 oz
25 oz

These also have a general wing span associated with them. For each of these classes I am developing a motor, battery and esc settup that gives the thrust that is appropriate to the performance needed.

For instance is if I want a 10 oz 3D aircraft, I need 20 oz of thrust, after searching this sight I find that a
lot of folks are happy with the AXI 2808/34 with 3s 830 lipo and 10amp esc swinging a 10 X 3.8 SF. So I
try it, like it and label it as a 10 oz - 3D solution. I could also fly a 14 oz or 20 oz plane with that set up,
but at a corresponding lack of flight performance, or I could put on a 2s 830 lipo and get a slightly lighter plane but less performance.

I think we could do the beginners a large favor by talking about the weight class of the airplane, and then drive the selections from that. That is my two cents.

Larry

powerchute50

Excellent stuff, thanks for your advice. I agree with the previous posts that electric is introducing lots of new people to RC modelling. We desparately need this, the glow crowd is getting old. The convenience and out of the box ready to go potential of electric has the potential to bring lots of new people into the hobby. Hopefully we will leave the era of underpowered electric foamys behind. We don't want new people to have bad experiences after shelling out 200 bucks for the plane and power system.

I am coming from the perspective of experienced modellers who are used to technical details and love scratch and plan building. I enjoy the technical challenges of this hobby, and that is why I am complaining about the lack of information on electrics.

This will change as time goes by and information on electrics builds up. It was the same with glow when manufacturers touted their particular kind of intake port and bearing surfaces with proprietary names that made no sense to anyone. Electric will mature, and add a very important aspect to our hobby.

A very merry Christmas to all on the forum, and best of the new year to everyone. Thank you for all the great input on this and all the other topics on this board.

Powerchute50, the original grumpy old man.

John E

When I started flying with proportional RC I put together an OS 25 with a 9x6 prop, medium dle bar plug, and 5% nitro for my 4.5lb trainer. How did I work this out? Was there a formula to use, or did I simply read about successful power packages for use with this model? Hows did I know what were also suitable models for this power package?

Electric is just the same, take an AXi 2820/10 with 8 RC 1600 cells along with a 12x6 prop and it will give the same model higher performance, or we could use a Mega 22/30/3 with a 10x6 prop on 10 subC cells. Once you know what a particular system will do it is then possible to decide on what other models the system will power. As you learn more it is then possible to do the equivalent of switching plugs, props, and fuel mixes. The problems come when people try to use unsuitable combinations. Manufacturers give performance figures for different props and cell combinations. The experienced IC flyer will know what prop at what speed will fly a certain model to match their expectations, and what wing loading they would find acceptable for a given model type and size. Dealers worth using will be able to put a complete combination together, and GUARANTEE that it will be successful - there is no need to support dealers who can't.

Best regards,

John

lwatson

My Feedback: (2)

John,

Not to pick on you, just to drive home the point. As soon as you said, "Take an AXi 2820/10 with 8 RC 1600 cells along with a 12x6 prop and it will give the same model higher performance, or we could use a Mega 22/30/3 with a 10x6 prop on 10 subC cells", I wanted to know the weight class of the airplane you were talking about, and the thrust being delivered. Without some grounding this all becomes techno-garble.

Larry

rmh

absolutely--
If you are a veteran of flying/ designing/ selling kits n planes - you know that the electric BOOM-has added a new group to the flying scene.
Many enthusiastic newcomers are complete novices with models of any kind

Given the basics - they figure it the rest of it - fast.
Many of em are very adept at computer stuff.
Simply saying "here use this ", does not do the job.
Just like playing a musical instrument - if you really want to get it right - learn the basics.

jooNorway

Powerchute50 ask some good questions. But ask someone who is not into RC "What is an .60-engine?" [X(] It is all about interests and experience... isn`t it?
OK, some of the deliverers don`t give too much info, they just push the stuff in "ready-to-fly" packs to earn money. Others are based on entusiasts trying it out on their own... like Hacker which I have never been familiar with.
Your Stinson will end up at a total weight of...? If you think it ends at 4 kilo then PJS sells motors classed at their pullability. A PJS 5000 will give you a thrust of 5000 grams and will suit. It requires 6-7 LiPo`s in serie and swings a 17x8 prop at nearly 50 Amp. http://www.mamut.com/controls/shop/s...d=29&subgid=31 Then you buy an ESC sized slightly higher, maybe 70 Amp?
AXI also offers a lot of info, a 4130/20 have these datas: http://www.mft.nu/motors/borstl/axi4130-20.htm and it says quite clearly: models 3,5 - 7 kilos. A 3,5 kilo aerobatic and up to 7 kilos of sailplane. Everything is crystal-clear I think [8D] But of course I am more than slightly interested in these things.
After 28 years of glow-trouble I have become an E-fly adict the last year... But my RC-pals have forced me to buy a fuel-to-noice converter again, a Funtana S90 powered by a beautiful YS-110. "you have to make noise too, not just fly" they says
Anyway; this hobby is a gift for adults never growing up.

E-Challenged

You're right, you it's hard to get get started in electric R/C and the makers and distributors don't make it easy without standardized power ratings, etc. At least they could express specs in English and metric systems. It is possible to buy a kit and follow the kitmakers recommendations as to power unit, number and type of cells and type of speed control required. Recommended hardware is liable to be somewhat obsolete by the time you buy the kit. Many of us addictively read threads on E-Zone under batteries and chargers and power systems categories and ask questions as to what works well with a certain kind of model. You can also get ideas and advice on what works from electric flyers. There are many electric modelers who are often electrical engineers or computer geeks and who enjoy using their math and calc programs to help us primitives choose motors and batteries, etc. To be fair about it, though, if you were just entering gas and glow R/C you would need to get help from various sources to choose the right size engine, prop, tank, servos, muffler pressure, etc., for a certain type and size of plane, then you would begin getting experience on your own and eventually advising others. Lipoly batteries arereplacing NiMh and Nicad for motor batteries. They offer lots of power at very light weight but they can swell up and burn your house or car down if you charge them improperly or damage them in a crash and fail to watch them for swelling. On the otherhand, the majority of Lipoly users have never had a problem and have great service from their Lipolies. We hear that there are many safety improvements on the way in battery technology. I fly both electric and glow but am gradually losing interest in glow mostly due to loss of nearby flying fields. Once you are experienced with electrics, it can be much more casual flying than with glow or gasoline power with no flameouts during take-off or engine dying on the far side of the field and nothing to clean up after a days flying.

Matt Kirsch

My Feedback: (21)

Everyone seems to be poking around for some "magic bullet" that will make electrics "intuitive." Don't you think that if such a magic bullet existed, that the manufacturers would've found it by now, and exploited it to the max? Make electrics drop-dead simple, and your sales are going to skyrocket! I certainly don't think the electric R/C industry is getting any jollies from watching people getting confused and frustrated trying to figure out how to use their products. Frankly, I'm not even sure some manufacturers truly know what their products are capable of themselves...

I'd love to see the day when electrics are drop-dead simple, but many things have to happen before that day, some of them not so good.

powerchute50

I think that things will improve in electrics over the next few years. I don't understand why at least one manufacturer doesn't grab the opportunity and put out clear and instructive ads, instead of the "we're the best brand buy us and don't think about it" approach. I read a Kokam battery ad a while back that gave a nice clear diagram of series and parallel battery setups with output voltages and amps. I tore out the ad and put it up on my shop wall. If a motor manufacturer would do that I would buy nothing but that motor. Seems to me that it would be a big sales advantage for them to grab the reputation as the easy one to use.

They are probably not interested since few people care about the details. They aim for packages. Those of us who love the nitty gritty technical stuff are in the minority.

Don
----------------
You don't learn anything if nothing goes wrong

50+AirYears

The first model plane for electric was a small low powered FF model back in the late fifties or early 60s. Electric flight had a slow progression until the late 70s or early 80 when ERCs started appearing. The first ERC I saw at our field was so underpowered that it needed a very hard toss to get an extended powered landing. We are now over about the last 5 or 6 years entering a real growth phase with better and more powerful motors, speed controls, materials, and just about everything else for model airplanes except maybe flying fields.
The thing keeping me from getting more involved with electrics than I already am has been mentioned here in several forms, but my interpretaion of it is this.
An .049 glow engine will fly a certain size and weight range of plane. Same with any other size of engine. These ranges are pretty well known from experience. You have a designation system in either English or Metric units that is standard among the manufacturers. You buy a kit or ARF, the box tells you a range of engine sizes to use, you buy whichever engine make you want to use within that range, and the engine manufacturer gives you a range of propellor sizes to use based on the type of plane the engine is going to be used. You have some relational information right there in front of you to refer to. For electrics, you have to use the anticipated weight of the plane, the wing area, what type of flight performance you want, then you have to calculate an estimate of the power requirements you need, then you have to get manufacturers data sheets on the various motors to find one that will turn some prop appropriate to the type and size of model at some efficient speed to get that performance and match the current draw and power to that motor/prop/flight envelope combination to get a reasonable flight time. Finally, you have to do these calculations for different motor manufacturers because there is no system of designators to relate one manufacturers motor to anothers. I know that a 40 from Fox is going to be in a close power range with the OS Max, with Thunder Tiger, Super tigre or other 40s. Same with 60s, 90s, 15s, or whatever. I know that my Astro 25 geared Cobalt is going to have close to the performance of a mid range 40 with 12 to 14 cells, and I know that in a certain plane the extra weight of 2 3000 mah cells will offset any power gain with the extra weight. So the owner flys with 12. I know this because somebody did the leg work and is flying this particular plane, and someone else ran an extensive test matrix and published the documents in another Website to help people choose reasonable cell numbers and prop sizes for various results. But how does this translate to another manufacturers product? Theres no commonality of designation for comparison. And this makes it harder for long term glow users to accept.
Notice, I'm not refering to the take it out of the box, add dry cells to the transmitte, charge the flight batteries and go group. They have things a bit simpler.
If I type any more, I'm going to be very late getting home to a mad wife, so I'll sign off for another day.

powerchute50

50+ Air Years

Great post, you wrapped it all up nicely. Us old glow/gas guys will get into electric when it makes more sense to do so. Some of the electric enthusiasts have countered with the fact that we all had to learn what a .46 glow engine would do so why all the complaining about electrics. The fact is that any manufacturers .46 engine will pretty much perform like anyone elses .46 engine. We have a common standard of comparison. Until that happens with electrics, it is just too confusing to try and compare across the many manufacturers and vendors. Once we get a standard, like your Astro 25 cobalt, we can build on that for other models. Eventually we will get it together. But the motor manufacturers have to give us some standard of comparison between them. This will happen at some point.

Don
-----------
You don't learn anything if nothing goes wrong

50+AirYears

They will have to come up with some cross designators and reference standards for their own long term survival. Just like in the early days of ignition engines, some mfgrs reffered to the size prop the engine turned, some gave a (dreamland) horsepower rating, some called out the ability to fly any model within a certain weight/size range. Everybody has since standardized on displacement for selecting engines.
One of our better pilots served as test pilot for a builder who was working up a scale push-pull fighter model. He had no trouble with the early developmental models powered with glow combos like twin 60s, a 40 and a 25, and the like. All the models were in the 10 to 12 pound weight range and 26 to 32 ounce/sq. ft. wing loading.
The final test version was a 12 pound SO scale model. Power was Astro geared Cobalt 40 tractor and geared Cobalt 25 pusher. Test pilot was skittish, as to this point, nobody in the club had seen a good electric. Electrics were experienced as underpowered childrens' toys.
With 34 cells in series, this model was the hottest performer of the series. The TP was talking about it for almost a year. Didn't even mind the 4.5 minute flight time limit. (Before 3300 mah cells.) He still is not ready to get involved with electrics himself though, because of the complexity of figuring out the motor/prop/gearbox/ESC/BEC/charger/battery pack/mfgr designator combinations. He prefers to build and fly, not go through arcane calculations.

jooNorway

As long as we talk 3D Foamies which usually have more than enough power it works fine with electrics. The problems occurs when it comes to bigger scale and aerobatic planes, or? Usually we add more than enough power when using glow-motors, but when it comes to electric it seem to me that we put a lot of calculating in which motor is "enough" instead of which one is "more than enough"... Resulting in planes being slightly underpowered compared to glow-mates! And therefore some think that electrics don`t work properly yet.
An example; a pattern-plane at 2,5 kilo (5 pund...) would be fitted with a hot .61 and tuned-pipe making the verticals unlimited. But then we step into the trap when it comes to electrics... choosing a motor that pulls 2,5 kilo... Being disappointed, claiming that electrics "is too young" maybe... Instead of putting in a motor pulling 4 kilo, and becoming an el-addict [8D] I would compare this by putting a .40 in the plane and still the plane would be airborne, but the engine is the wrong choise! Wrong motor for the project, but this motor would be a hit in a smaller plane of course.
OK, the cost is heavy when it comes to big birds, and especially when the modellers feel that it is hard to do a safe choice. It still feels safer for the common pilot to pick an OS91FX for his 4 kilo (8 pund) warbird than calculating on electrics, but in fact it is as easy as this: pick a brushless that would pull 6 kilos straight up... How much Amp? Then pick an ESC that is able to do the job, and LiPo`s suiting it all!
I have used the calculations and measurements made by other el-addicts and manufactors (a Scandinavian phenomena???) and also done my own tests both static and practic and of course discussing and reading ending up without doubts when choosing set-ups and of course I say: Electric is the future, but it is also today
The problem is: (you have already mentioned it) make the datas readable for everyone! The entusiasts do not want to get all this ugly bad tasing oil from the fossile fuel-planes on our el-planes when we go flying... [&o]

raabid

When my neighbor and I got into electrics, four years ago, there were no brushless motors and there were no lipolys. We hadn't flown gas, and he got a Megacrap Merlin, and I got the Graupner Tipsy. Neither of us knew how to fly, consquently we became skilled repairmen. I played around with building my own airplane, no plans, just basic ideas on what airplane looked like. The more we crashed, the more we learned but my self-designed planes still couldn't get airborne. Until....My neighbor bought a wattmeter. Then we could see what our power systems were doing. Right off the bat, we learned that not all batteries are equal. You had to have the right size batteries to dump enough amperage. The more we played with setups, the more we learned. Then we found Ezone. Lotsa questions were answered there. Brushless, lipos, RcUniverse came into being, and here we are now.

I agree with some of the things being posed here. Yes it is confusing to choose between motors, and no I don't want to go see what Hobby Lobby is putting in their ______ plane. Motor designations are confusing, how will knowing the size of the can in millimeters, and the number or winds and/or length of stator, help me choose? Why would I get a 16 turn motor, and not a 18 or 14.

However, confusing things aside, there are easy things to understand. If you have a glow model and want to electrify it, you can't just pick a motor, or a battery you have to look at them simultaneously, unless you have one that is suitable to the plane and the performance. If you just swap motor /battery for engine/fuel, and don't do anything else to the model, the wing loading's going up.

As far as what size motor to pick thats easy! It's already been said once.
You just glossed over it, because it was stuck in with all the other electrigarble. I was looking for it to come up so I saw it.

First,
In general most setups will weigh the same amount as the airframe.(i.e. A plane that is 5 lbs., will have around 2.5 lbs. of batteries and motor.)

Second,
How do you want the plane to fly? Is it a scale commercial airliner, or a profile 3D.
There are electric parameters.
50W/lb - Needed ROG
75W/lb - Mild aerobatics
100W/lb - Aggresive aerobatics
125W/lb - 3D and beyond
150W/lb - Helicopter with wings.

So for the 5lb (3d plane) you want 2.5lb of motor/batteries that will produce 625 Watts.

Where to look from there is a matter of reading and looking around.
I have been the happiest with Mega motors and Himaxx as they list the max amps and voltage for all their motors. I HAVE YET TO FIND A SITE FOR HACKER THAT DOES THIS. I'm not yelling that as a taunt, I've wanted to get a Hacker Motor for some time but can't find anywhere that will give me recommended cell number and amps. And don't say just look it up on Motocalc, because it's not the end all be all. That'd be like throwing a baseball from the stands. More than likely, it's going to land in the ballpark, but doesn't tell me where first base is. I'd rather see the numbers someone read off their wattmeter.


My two cents.

powerchute50

I think the other thing about electrics is the 3-4 minute fly time. When you get into bigger planes and have a hot setup, the LiPolys will probably give you less than 5 minutes. Then what? You do a 5C charge on the Triton. If you don't want to wait, you pop in a second battery pack for another 4 minutes. Then what again? Now you have 2 packs on the Triton and sit and watch the glow fliers. And each pack cost you close to a good .40 glow engine.

Meanwhile the guy with the .40 glow engine has been flying for half an hour and is working his way through his second can of glow fuel. You can fly all day with a glow or gas engine. Electric is like war. Ten percent pure exhileration, 90% pure boredom.

I think we will always want glow/gas engines. I agree that electrics are an important part of the future. But even if batterys double in endurance, you will still want a glow plane in the truck to fly while all those expensive batteries are charging.

Don
---------------
You don't learn anything if nothing goes wrong

AgCat1982

I don't want anything but electrics. So, I was very irritated when searching the threads for what kind of setup would work on what I had. I would read all kinds of posts about someones plane flying with such and such battery and motor. But, NOTHING about how big the plane was or even its weight! I finally gambled on a setup and it worked great! I was mostly lucky. Since that time, when ever I am talking about my plane to someone, I tell what motor I have, the prop I have, what batteries I am using, the type and size of plane it is and how it performs! If everyone on the forums, who has a good flying setup, would just give the above information when talking about their planes there would be a boat load of information here to work from! I think that is what is needed the most. A ton of actual examples of flying planes and what is making them fly! It would greatly help new comers get their foot in the door!

In reality, it's very hard to find examples with ALL of the above information listed with it.
A few are there, but, not many. There is, at least, ONE of the components left out making the information useless to some one just starting out. Been there!

jooNorway

agcatsbest: on the forum which I write reviews for (Norvegian) we try to add not only info on the planes and motors chosen in the review but also try to suggest other motors/batteries that will suit the plane! And which ones that suits different flying-styles. This info is great for the readers they say!! A review is not published before some other pilots/writers have discussed the text and conclusions adding their experiences and trying to really make it worth reading. If a product is no-good then we tell!
I have a feeling that in Europa and Scandinavia there are much better reviews and forums and web-sites where the pilots share their experience, not depending on commercials...

Flypaper 2

Saw an electric warbird flying a couple of yrs. ago and decided, I want one of those, Found out what was used in it and been flying mostly electrics ever since. All my alky burners just sit, now. Flys for 1/2 an hr on a charge. With four batts and the charger, I can fly nonstop all day. Time out fur a sip of beer once in a while By the way powerchute, You should get more up to date stuff. Lipolys charge at 1C . Great for us 69 yr. old farts. No hard starting engines, no oil to wipe off. Just throw them in the van, and I'm gone.

geoffbeneze

Don,
While this thread has broght out some very good information, it really appears that you're working overtime to support your prejudices.

This is ok, we don't ALL have to fly electric, just as we don't all have to fly the stink potters.

The key issue to remember here is that "different" DOES NOT equal "wrong."

I've only EVER flown electric. Stayed out of flying, even though around it all those years UNTIL electric came along. I've had no problems.

powerchute50

Flypaper - Guilty as charged. I am not up to snuff on the latest in electrics. Just what I read in the ads (Kokam said 5C in some ad I read, can't find it now). I'm not trying to be a wet blanket on electrics. Just the contrary, I really want to get into them eventually. I am impatient for manufacturers to get their act together and put out information that makes sense. And as for flying a hot and heavy electric aircraft for 1/2 an hour, I don't think so. Foamies maybe. And what did 4 LiPoly packs set you back?

Glow and gas just make more sense right now, certainly from a scratch building and expense perspective. Our club is getting into combat big time with the corrugated plastic sheet and evestrough body spads. You have to fly long and hot for most of the afternoon. No way electrics could take it, at least not without spending a fortune on battery packs. Giant scale is still best with gas, so is float flying. Lots of components of this hobby will probably always be best with gas. Besides, a gas engine is "real", sort of like the full scale thing.

Still, electric offers lots of potential, and lots of convenience. It is great that it adds to our hobby. What is best is that a lot of young people are buying foamies and flying them. The glow/gas crowd is getting old, and we don't seem to be recruiting many new members.

Don
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You don't learn anything if nothing goes wrong.