WARNING! Newbie Alert!!

[LaurelUK]

Hi

Whilst I have built flying models before, I have never flown any, and am certainly a newbie where electric models are concerned.

I am planning to build a model Hawker Typhoon, which has been desinged to accommodate a .60 glow engine, but I am very interested in converting the model to run with an electric motor instead.

Problem is that I really don't know where to start. I'm not even sure what equipment I will need to buy in order to make the conversion. I am also concerned about weight differences between glow and electric motors. Is this a valid consideration? Is ballast required to set the centre of gravity when changing motors? I really don't know.

If anyone can help, or perhaps point out a website that can, I'd be very grateful.

Please excuse me if the information I am asking for is already available in this forum - I did look, but couldn't find it - honest!!

Thanks.

[abenn]

Welcome to the forum. I'll start the ball rolling, though I'm sure there'll be plenty of others with references to good sites and/or good posts in this site. Have you checked out the "stickies", for instance, at the tops of the pages here?

I started converting glow to electric about a year ago, with a Flair Magnatilla and a Flair SE5A. Choosing the right motor is an art in itself, but there are useful rules of thumb, such as you need about 50 watts per pound of all-up model weight for leisurely flying, up to 100 watts per pound for spirited flying. Both of mine are about 400 watts and 6lbs.

The next most difficult thing (or perhaps the most difficult) in glow conversions is where to put the batteries. If you're using NiMh (as I do) or NiCad, their positioning will have a great influence on the C of G, but the structure may not permit you to put them in the optimum position without major mods. Magnatilla was ideal in this respect, for there's acres of empty space inside; the SE5A was more difficult, but doable.

If you're going for LiPos your problem will be slightly different, for the electric motor will undoubtedly be lighter than the glow motor, and there may not be enough weight in the LiPos to get it balanced properly without adding lead.

[Milton]

It is nice to be able to come to forums like this for information on setting up planes but if you know of a club or group of Electric flyer's in your area try to meet them and get some information there , Plus you might see what you are looking for already set up.
I know a lot of people say that a plane will fly on 50 watts per pound but I like to use 75 to 100 watts for good sports flying.
Watts is the volts times the amps you are running.
If you have a 3S battery (3 Cells of 3.7 volts) that will hold 3.4 volts per cell under load of the motor will be 10.2 volts.
Now you have a motor that will take say 30 amps under full load. That would be 10.2 X 30 amps = 306 watts. Now 75 watts into 306 watts = 4.08 lbs of plane that the system would fly.
So the best way to set one up is try and know about what the weight of the plane will be and start from there.
The last plane that I set up I was trying to get a all up weight of 18 lbs. So I started to look for a system that would give me 2,000 watts.
I decided that I needed a motor that would handle a load of 70 amps with 8S battery would give me 1904 watts. The plane turned out to be 18 lbs 9 oz and the watts turned out to be 1980 and has plenty of power for sport flying and a little extra vertical.
Picture attached below

Milton

[LaurelUK]

Thanks Abenn and Milton, your comments are very well appreciated.

You both make the whole subject sound easy, not at all the impression I get when I'm looking for info on websites.

As I have said, I am new to electric flying, and one question sticks in my mind - How long can you expect the batteries to last during a flight - I realise that this will vary, depending on setup, but some indication will be helpful.

In fact what, in your opinion, are the pros and cons of electric flying when compared with glow flying. My initial attraction to electric is that it seems so much cleaner than glow - The less residue on my model the better!

I'm sorry if I am asking such basic questions, but (Abenn) I can't seem to see any 'stickies' on the subject :) and everyone has to start somewhere :D There are some clubs locally, but at the moment its a case of being able to choose one, and commit time and money to the cause (i'm writing this at work - too many other things to do at home :D )

Thanks again!

[abenn]

There's a big beginners sticky in the Beginner Training Area forum, and another one that might be useful in the Power System forum.

So far as battery duration is concerned; once you've decided your total watts requirement, and whether you'll achieve it by more volts and less amps, or vice versa, you then pick a battery pack. What you pick will depend on how much money you want to spend, what amps you're planning to use, and how important is it to save weight. Whatever chemistry you choose (NiCad, NiMh, or LiPo), all packs have a mAh rating (milli-Ampere-hours) which tells you how many milli-amps they can deliver for one hour. So, if we take an example of a model that's going to draw 30 amps, and you put a battery in it with 2400mAh capacity (2.4Ah), it will deliver that 30 amps for 2.4/30 hours, which is 4.8 minutes. In practice you don't always fly at full throttle, so you'll get more than 4.8 minutes.

The other battery parameter which is important is its C rating: The 2400mAh battery running at 30A is delivering 12.5 times its mAh rating (30/2.4). Most NiMh batteries are happy to do that, and more, but some LiPos have a C rating as low as 7 or 8 (though they may advertise higher) which means they can only deliver amps at the rate of 7 or 8 times their mAh capacity -- i.e. 16.8 to 19.2 amps for a 2400mAh pack. So, with a low-C LiPo, you would have to buy a larger capacity in order to get the amps you want. Of course, this isn't wasted, because with a higher capacity you get longer flight time.

I think a simple way to look at those two parameters is to compare them with a fuel tank: mAh is a measure of tank size, and C is a measure of how big the outlet is.

[LaurelUK]

Thanks for your help ABenn, its given me a lot to think about, although I'm sure I'll be back with more questions later. :)

[sp1nm0nkey]

From what I've experienced, there's no really good reason to go either glow or electric. It's all what you like. Electric tends to be more expensive (small electric planes are cheap, but once you get into big ESCs and big brushless motors and giant lipos, it gets very very pricy), and a plane loaded up with lipos also tends to be heavier than a nitro plane. Nitro isn't really that messy, I just went went to glow after a lifetime of electric and it's not bad at all. It's just more fiddley, there's quite a bit of tuning. Once you get the plane up in the air, it's pretty much the same besides the sound of the motor and the trail of smoke (hopefully you don't get this with electric.) If you do end up going electric, you can pretty much fly anywhere, but the whole idea of special fields for glow is that it provides a nice place to fly and a safe environment so if you have larger models it's best to fly there anyway. The best advantage of electric is you don't have to pay for fuel, but then again there's the cost of lipos up front with electric. In the end it's really just a wash, pick either one and you'll be happy.

[Tweet]

If you haven't flown before I wouldn't start with a Hawker Typhoon. I would start with one of the many good trainers. I have a Sig Kadet Senior running on 5S that flies great.

Generally, an ESC/motor combination is about the same $$$-wise as a glow or gas motor. Then you have the battery cost. With some planning you can purchase your airplanes so that two or more airplanes can share a set of batteries. For instance, the airplanes I have either run on 10S (large scale airplanes such as a 28% Wild Hare Extra or using only one of the two 5S battery packs on a Sig Kadet Senior), 8S (such as a Funtana 90), or 3S (high performance park flyer such as a Mini-Edge).

If you start a thread stating what airplane you want to convert with its specifications people will jump in and help you.

For the most part I fly airplanes that were designed for glow or gas power as electrics. I think glow is a mess, the vibration from glow and gas motors is hard on the airframe and radio system, and I personally don't enjoy tinkering with small gas/glow motors. Lipoly batteries are expensive for sure...I manage the expense by having a strategy to minimize the number I need to buy.

Many airplanes have been converted successfully. If you find one you want to convert then perhaps someone has already done it and you can benefit from their experience. Here is one of many good threads on converting a Kadet Senior.

http://www.rcuniverse.com/forum/Sig_Kadet_Senior_ARF_Conv%25/m_2784022/tm.htm

[LaurelUK]

Thanks Sp1nm0nkey & Tweet for your advice, lots to think about there.

If you haven't flown before I wouldn't start with a Hawker Typhoon. I would start with one of the many good trainers.

I'm not intending to learn on the Typhoon - I have experience in building models, just not flying them. I have a small biplane trainer on a .15 glow that I am hoping to learn on, once I find a local club to help. I'm just planning ahead by trying to decide which road to go down with the Typhoon.

Anyhow, thanks everyone for the kind info - its nice to find a forum where you don't get flamed for knowing bugger all!! :D

[Tweet]

You can probably learn on just about anything if you have someone help you on a buddy box. Also, using one of the flight sims will help.

The best airplane to learn on is probably still a high wing trainer though.

[mariuslj]

Hi

I'm going to breathe the unthinkable: You'll probably start up cheaper and get more stick time learning on glow engine and a high wing trainer.

The fun of electric flying in my case is in the science of the exercise: Scheme the shemes, ponder, do the calculations, ponder more, build and fly. If you are treated to success: what a feeling of accomplishment!

Also keeping a Tucano, Cub or whatever in the car, then flying on a (short) lunch break or before work or on the the way home. No mess no fuss.

BTW, try the electric flight FAQ's on the ezonemag.

Marius

[E-Challenged]

Why attempt to convert a glow model to electric power as a first attempt? If you are drawn to electric, choose a simple high-wing model designed for electric power and follow the designer's recommendation for motor/geardrive and battery pack etc. It would also be good to get experienced local flier recommendations on kits, motor, batteries, chargers, speed controls receivers, servos etc. Kit designers often recommend motors and battery packs that give marginal power/performance.

If you are drawn to glow engine power, again, choose a simple high wing trainer model and get advice from local fliers. If there is a local club, join it and get all kinds of help during building and test flying process. After you have some building and flying experience, work your way up through higher performance models including low-wing warbirds when you have the experience and reflexes.

[TipStalled]

Here are some examples of SUCCESSFUL conversions....Cheers !! :D

http://www.hobby-lobby.com/glowtoelec.htm