Hi,

I am still in the process of soaking up enough information to be able to choose a first plane and club. I have it down to a handful at this point and then this really dumb question occurred to me. What is the difference between a 40 and 60 sized plane. I originally figured it was wingspan, but I have seen 40 sized planes with 6 foot wingspans, just like a lot of 60s seem to have.

So, is it the weight of the plane or something else that determines whether it is a 40 or 60?

Also, when it comes to engines, it seems that most people recommend using a size bigger than the size of the plane. For example, in a lot of threads I have read, people seem to be recommending .55 sized engines for 40 sized planes. While I am sure the sig LT40, for example, would work just fine with a 46 AX, would there be much added benefit from sticking a 55 in there? Is a bigger engine always better or can it be too big, given that it can fit in the engine compartment ofcourse? I assume diminishing returns also begin to set in at some point. Any help on this would be helpful. A link to a website that discusses this would be even better. I just haven't been able to google up a site that discusses engine size in layman's terms.

Thanks!

P.S. From my perusing of the forums, I am getting the impression that Top Flite makes the best ARFs. The stuff on their website looks awesome. Is there any other ARF manufacturer out there that would be equivalent in quality, or better? (Not that I plan on buying one anytime soon, but it is always fun to peruse the "Ferraris".

I am quite new to the hobby but to give you just something to work with regarding your questions. I'm not too sure about what makes a 40 size plane and what makes a 60 size for example, it could be frame size and strength I think. Yes on a 46 size plane you can put a 60 size 2 stroke engine  (I have done it and a lot of others aswell). But yes regarding your question about can it be to big - it can. It is never really a good thing to overpower your plane. This is the reason manufacturers will give an indication/recommended engine size for a plane which they will also split into 2 stroke and 4 stroke.

Hangar 9 makes good models and there are a couple of others aswell. I will rather not comment to much on this since others can help you a lot better. Good luck</p>

Generally speaking, that denotes the engine size for that aircraft.  Not withstanding, though, that is usually in the order of a recommendation for general flight.

If you take a 40 size plane, they will often recommend a range, say .40 to .55 two stroke, or .50 to .65 four stroke (not that such beasties exist, but it's an example).

That usually goes with the type of plane, the airfoil arrangement, wing span weight, and so on.  A good example of this is the Sig Kadet, a trainer with a 70 inch span takes a .30 to.40 engine where their Four Star 60, a low wing itermediate level aircraft, has a 71 inch span but takes a .60 to .75 size engine.

Hope this helps.

CGr.

You probably realise that your question is one of those "can of worms" instigators.

Well, I've never been one to shrink from controversy, so here is my opinion.

Firstly, one of the very best and most practical trainers is the ARC Ready. I say this because it flies well, is tough, fuelproof and quite attractive. You may have difficulty in sourcing one, though. I think that the Chinesemight have done them to death with their cheap imports.

Secondly, I would recommend that you learn to fly using a modestly-powered model. This will compel you to be considerate of the aeroplane's wing... and this is the model pilot's primary skill.An ARC Ready with a .25 or .30-sized two-stroke engine would fit the bill.

You can always fit a larger engine at a later date.

If you do fit a very large engine, you may find that it gives you problems when landing. Even at idle, it maybe developing sufficient power to sustain your model in flight. So, you'll struggle to land your aeroplane with accuracyand may not learn how to properly control its glidepath and approach "speed".

engine size takes a look at various things....wing span, weight, wing loading, and intended use (trainer or sport etc)......
trainers are great....they, along with an instructor teach the student to fly....because trainers aren't speed demons, are forgiving of mistakes, and are tough.......
now you go and put a bigger engine on a trainer...the airplane weighs more, wing loading is more, the basic airplane has not changed.....you get some more speed and more vertical...but it is still a trainer....it still flies like a trainer.......lets be honest...kinda hard to knief edge a trainer the length of the runway.
let trainer be trainers when you are ready to move on, go to a different kind of airplane so your learning can continue.....</p>

Good answer from jetmech05.

It's a combination of size AND shape. For example, an Ultra Sport comes in a 40 and 60 size. Construction is identical, but the 60 is larger. The 40 uses 1/4" wood for the stab and fin while the 60 uses 5/16" wood. But both of them are smaller than the Sig LT-40 which is a 40-size trainer

Contrary to popular belief, it is not always beneficial to over power a plane. Of course, some people will tell you otherwise, but they are the same type of people who's famous, last words are, "Hey ya'll, watch this!"

Top Flite's ARF selection is fairly limited, and all of them are intended for experienced pilots.

There are quite a few good ARF brands and most have a broad selection starting with trainers and going all the way to advanced models. I put them in alphabetical order and I know I probably missed a bunch, but these are the ones I thought of in a few minutes.

Global, Goldberg, Great Planes, Hangar 9, Hobbico, Phoenix, Seagull, SIG, Thunder Tiger, Top Flite, Tower Hobbies

Generally speaking the manufacters recomendations are good. Also the purpose of the plane is most important. A trainer is totally different than any other in appearance as well as performance. Also so in all other aspects, function designates design. Yes there are some that must have all the power possible not usually beneficial but just there hang up. Definitly under powered is bad but overpowqered is not necassarily good. It will be heavier, costl more burn more fuel, may fly faster but not better. As with most things find the happy medium. One other note that is usually true bigger is better in regard to flight chararistics in respect to size of aircraft.

A 40 model is a plane powered by an engine having 0.40 cubic inches of displacement.
Using glow fuel (nitromethane), such an engine is able to generate around one horse power at full rpm, if it is a two-stroke; or around 30% less power, if it is a four-stroke, depending on the manufacturer.
A 60 model is a plane powered by an engine having 0.60 cubic inches of displacement, and so on.

Each designer tests and recommends a range of engine’s size for his creation, for two and four-stroke glow engines, and sometimes for two-stroke gasoline engines (for big heavy models using engines above 26 cubic centimeters (1.6 cu.in.)).

Here you have some links to related good information for you to chew:

http://www.masportaviator.com/ah.asp?CatID=8&ID=46

http://www.masportaviator.com/ah.asp?CatID=8&ID=95

http://findarticles.com/p/articles/m...g=content;col1

http://findarticles.com/p/articles/m...g=content;col1

http://findarticles.com/p/articles/m...g=content;col1

That was paerfect lnewqban, exactly the type of reading I am looking for.

Thanks a lot.