I'm interested in getting into electrics and was going through the FAQ's. Some of the info there was of help but did not answer many of my questions. I wanted to place a post but there was no reply box to post in!? [&:]

As some one who knows nothing about electrics, I would like to see a basic quick reference list covering what a newbie to electric and/or R/C needs to know to get started.

So, here are some newbie questions to cover:
-What is the best application for geared and direct drive for motors? ie: slow scale flight or 3D.
-Prop sizes for application of geared and direct, ie: 3D, large or small dia/fine or coarse pitch?
-Prop sizes for motor size and type. ie: speed 400 with 3:1 gear requires what prop size?
-Recomended motor type, geared or direct for weight and wing area.
-Recomended prop size for weight and wing area.
-What a prop size is best suited for? ie: large dia with fine pitch.
-What are the best type of batteries to use for the type of motor used?
-What application each type of battery (nicad/nimh/lypo) is best for.
-What size of battery is needed for the motor used? ie: Volts/amps/cells for speed 400.
-How does volts/amps/cells relate to motor performance and flying performance?
-How do these batteries effect the receiver, is a receiver battery needed too?
-What is a good charger to get?
-What other electric components are needed? ie:speed controllers and what the ratings mean.

For example, I fly detailed scale and want to fly slow. I already have planes of particular sizes that I want to install with electric, but don't know what to get. Other people fly different types and would want to know what they need for their type of flying they want to do. A quick reference would be extremely helpful for those of use wanting to get into electric but don't know where to begin. It's very time consuming to go through the posts looking for the info and that info varies by preference.

I tried to ask all I could think of and some questions maybe be silly but we are newbies.
If anyone else has questions I did't think of, add them to the list.

Maybe we can get the experts to make a quick reference for us newbies.

ZZ

Most of the questions you listed come from a "one solution" approach to electrics. Unfortunately, and fortunately, you can't approach it like that. There are literally hundreds, if not thousands, of practical, viable electric solutions for every airplane, versus one glow-powered solution. There is no one motor, no one prop size, no one gear ratio, no one battery type... Nothing, and I mean NOTHING is set in stone when it comes to electric hardware. Having hundreds of solutions makes things more confusing when you try to look at it from a "big picture" perspective, but it does make it MUCH easier to come up with a successful solution.

The most important factor in an electric powered plane is power, which is measured in Watts (metric Horsepower). Watts are Watts, and it doesn't matter how they get to the prop, as long as they get there in an efficient manner. In other words, it doesn't matter what motor you use as long as it can handle the power you're trying to put through it. Motors are chosen based on how much power you want to put through them, not by how much power they produce. Glow engines produce power, electric motors only transfer it.

What produces the power in an electric? The battery, Volts and Amps. It's not just the "fuel tank." Multiply Volts times Amps, and you get... drumroll please.... Watts! Electric Watts are the same as mechanical Watts, meaning that the Volts and Amps from the battery translate directly to the Horsepower being put into the propeller

As far as propeller choice, you generally want to plan on turning the largest propeller that can be put on the plane without creating a ground clearance issue, using a gearbox if necessary. Glow engines throw away as much as half their power thrashing the air with small propellers at high RPM. The engine is trying to pull an airplane that can only go 50-60MPH at 70-90MPH. Since the airplane can't go that fast, that power is wasted. With an electric motor, and gearing depending on motor choice, you can get the same performance, or more satisfying performance, on signfigantly less horsepower.

I know this doesn't answer your questions, but hopefully it'll give you some insight as to where to concentrate your efforts in the learning process.

Matt, it sounds like setting a plane up for electric will be an experiment unless I have electric experience. I could go through many motors and batteries to get the results I want.
I see countless products out there to choose from and that adds much to the confusion. I was not asking for specific detail information for a particular application, but for generalized catagory info that would help set up any plane I would want.

If I picked a motor that was to small for my plane it would not fly. Too big and too much weight. I thought there would be a guide line as to what motor to use for a weight and wing area range that would help.

If I wanted my plane to fly slow, I would choose a larger prop with a finer pitch. So How am I to know what motor to choose for the prop I want to run? I imagine I would be using a highly geared setup. Once the motor is selected then I would choose my battery to suit the motor?

I have been reading where electric motors tend to get quite hot as well as batteries. Is this because they are trying to turn too large a prop, too much battery, or is it something else? How am I to know how to avoid this, or is it just a part of electric power?

I assume then, my best course is to just simply ask exactly what I need for the particulars of my plane. The plane I am working on is a WWI Halbersadt DII. It's a biplane with a wing span of 34". The wing area is 408sq.in. I don't know what the weight will be, it's being scratch built, but I will guess about 24-30oz. I want slow scale flight performance. I want a 9"-10" prop. What motor and gear ratio is best for me? I want flight time of 10 min or better. How many volts and how many cells should the battery be? What are the best product choices for a newbie? I don't want to spend a fortune yet.

ZZ

No, not an experiment at all. It doesn't even require fancy calc programs, "Whattmeters," voodoo, or anything like that. That stuff's nice to have, but not really necessary if you understand the concepts.

You're still thinking along the wrong track. The motor is NOT where the power comes from, and is not where you should be concentrating your efforts. It's tough, but you have to throw that "it's bolted to the nose, therefore it's the source of the power" mentality out the window to work with electrics.

If you plan ahead, and figure out how much power you need first, you will have some criteria by which to choose the motor. Remember, the BATTERY is the source of the power in an electric. Batteries make Volts and Amps. Volts and Amps make Watts. 746 Watts makes 1 Horsepower. Horsepower makes your plane go.

Figuring out how much power the plane needs is pretty simple. It's generally based on weight and desired flying style. Keith Shaw came up with the original Watts per pound rules of thumb many years ago. These days, there are really only a couple that apply:

1. For glow sport plane performance, aim for at least 100 Watts per pound.
2. For 3D performance, at least 125 Watts per pound, preferably more.

This Watts per pound is for the plane's final, all-up weight with motor, batteries, and radio gear. With modern LiPolys and brushless motors, it's quite plausible and practical for the plane to come out within the manufacturer's recommended weight range, so you can use the high end of that recommended weight range for your estimates. If you're using NiCd or NiMH, you'll have to figure on going 20% over. You don't have to nail the weight to the ounce, you just have to be within 10%-15%.

Once you have a Watts figure, you split it into Volts and Amps to size your battery pack. I like to keep my power systems on .25-.60 glow conversions at 40 Amps, because it gives a good balance of weight vs. duration. You don't have to haul around a super-heavy, high-voltage pack to support a low current, and you don't have to put up with 2-minute flights.

With Volts and Amps in hand, you can now go motor shopping. All motors have maximum cell count (in terms of NiMH/NiCd cells) and current ratings. Figure one Volt per NiCd/NiMH cell, and that's one less calculation you have to do

Having a cell count and maximum current narrows your choice of motors greatly. Now, you can concentrate on whatever factors are most important to you, such as price, weight, and/or quality.

To gear or not to gear? That's another post for later. I gotta get to work.

I know, lots of words, but the entire process takes a couple of minutes at most and is actually quite simple. Electrics are more complicated, but that's the nature of the beast. You're building your "engine" from individual components, not buying it predetermined and preassembled like a glow engine.