Motor size question
 

I just got the Tower Trainer 60 and I have a TT46 Pro. The manufacturer suggests a .46 to .61. Is this enough motor for it?
I believe it probably is because it can turn a 10X6 easy and probably an 11X6 once its broken in.

Motor
 

Go with the .61FX o.s, will be a great engine for this plane.



Dbow

Motor size question
 

Seeing as you already have both the engine and the plane, my inclination would be to use both. Light planes fly better than heavy ones, so that's one thing that will work in your favor using the smaller engine. Don't rush out to buy a larger engine until you've given it a shot.

Thanks
 

Thats what I was going to do but I just wanted to get
at least another opinion on it.
Thanks again!

Motor size question
 

Yeah, I agree. I originally had a .40 on my Tower Trainer 40 and it flew just fine. I did, however, end up replacing the .40 with an OS46FX and the plane flies even better. I love flying it with either engine.

Trainer 60
 

The trainer 60 is built rather heavy. You would be able to fly it with the 46 pro but just barely! If you are flying off a grass field and the grass starts to get long, you may have trouble getting the plane up to flying speed. If you have the plane already then I would find a good 60 engine to go with it. You might want to check out the World models line of engines. For $88.00 U.S. you can get a Tiger Shark 61 engine that would work really well without breaking the bank. I have the 75 size and they are super quality engines. :D

Superstar 60 & OS65LA
 

I have the Hobbico Superstar 60 with an OS 65LA in it.


The plane flies very well with this combination, it will get up to speed and take off from grass at just over 1/2 throttle.

OS recommend a 12x6 for break in and a 12x7 for general use. I'm still using the 12x6 with good results.

These ARF trainers are very solid with ply fuselages. Although the plane has more than enough power for its intended use, I wouldn't even consider flying this plane on a 40 or 46....

Besides, there's the balance issue.... If you put a small light engine up front, you might end up making up the difference in lead weight....

Hmmm
 

Why would they suggest a .46 then? I fly off of asphalt.

Ive got another motor
 

The only other motor I have right now is a ST G90. I think that would be too big for it.

Re: Hmmm
 

They're not exactly "suggesting" a 46, they are simply telling you that a 46 will fly it. But a 60 will fly it better.

Just like you can get some cars with a 4 or 6 cylinder engine. Sure the 4 banger will give you better gas mileage, but the 6 will get you up the hill faster.

Tower Trainer 60 vs Superstar 60
 

Go to the Tower Hobbies site and compare the two planes. They are practically IDENDICAL. I wouldn't even consider trying a .46 in it.

But:

If you want to, you could get your AMA instructor to fly the plane with the .46, and when he crashes it because it's underpowered you can get a new one from Tower Hobbies..... :)

What about my G90 that I have?
 

That is a good idea about the.46 and an Instructor.

I have a Supertigre G90 that I could put on it.
Too much motor?

Motor size question
 

A flat-bottom wing on a trainer like that doesn't exactly need a whole lot of power to fly. A friend used to fly a 52" Cub on an OS .10fp. You won't have the power to go vertical, but then again it's a trainer and not designed for that to begin with. Use a 12x4 or 11x5 prop, and you should be fine.

Motor size question
 

Helicool,

I think mikel pretty much summed it up..

I've noticed that the trend today seems to be if the manufacturer says use a .61 then a .91 is by far better.. I don't 100% agree with this.. For every person that says more power can't hurt and you can allways throtle back. I say yes your right after you have learned throtle management will become second nature but untill then you will be concentrating on keeping control of the plane and will probably only fly it at a constant throtle setting that your instructor has determined for you.

Now I'm not starting a war here since I realize how many take the "Tim Taylor more power ugh ugh approach" when selecting a power plant for their model.

One thing I will say is that I've personnally seen many trainers crash and burn on aborted landing approaches when the "pilot" slams on full throtle and the torque and resulting stall causes the plane to spin in from 10 feet.

If you start out using the .46 and actually learn how to fly the plane on the wing as opposed to the engine I believe you will become a better pilot quicker.

In the past 8 months I've learned more about "fine" tuning my control inputs during flight from flying my GWS tigermoth then any other plane. This plane is under powered and requires you to fly on the wing. It also has a lot of drag because its a biplane which requires you to manage throtle the entire way in if you want to grease the landing.

Just my opinion but I would first use the .46 and then evalute the need for a bigger engine based on you actual experience rather then buy a new engine based on speculation.

Please note I feel confident making this statement because of the high lift generated by flat bottom airfoils found on most trianers if this wasn't a trianer but a sport or warbird with a much higher wing loading then my advice is to select an engine in the middle to high end of the manufacturers range.

Re: What about my G90 that I have?
 

Yup, way too much......

On this size airplane the max diam prop you want to use is 12" due to ground clearance.

The .46 might be just enough power to fly this plane and the resulting engine magagement may suit the engine as it's an ABC. You'll probably need to keep the revs up to hold altitude.

The engine weight is also a factor. OS states that a .46LA weighs 9.6oz whereas the 65LA weighs 18.87oz ( I know yours is TT, just a comparison..).

Since an ARF is pretty much built, the 9oz difference in weight will possibly show up as a tail heavy plane with the smaller engine.

Ideal characteristics in a trainer, tail heavy and underpowered!! :D


Comparing a Cub to a heavy plywood ARF trainer isn't really fair. I've got a Zephyr which has a 62" wing and that only has a .15 in it. But it's a very lightweight structure.

ARF trainers are very durable and therefore heavier for their size. Once it's up there though it will 'float' and fly on the wing. It just needs a bit more power to do it.

So it will fly okay?
 

So, it will fly ok then? I got this plane because I needed to start practicing landings. I was flying some SPAD planes I made, but they would always come in way too hot because of the weight. This same motor pulled those planes well on the flat and level but didnt have much climb out. This plane is way lighter than those others so I think it will be alright.

Thanks again

Re: Re: What about my G90 that I have?
 

And the TT46 Pro weighs about 18oz... not to mention the fact that it doesn't have to be tail heavy. There are ways of balancing that don't necessarily include adding weight.

It's a valid comparison, as it illustrates the point very well. His TT46 Pro will swing a 12x4 at 13,000 or so RPM. That's plenty of thrust to fly that airplane. It won't go straight up, but it will fly rather nicely.

I don't know about the rest of you, but when I fly a trainer I don't bore around at full throttle. I'm usually down below 1/2, and that's plenty to pull it around without worry. Putting a 90-size on that 60-size trainer will only increase the wing loading, stress the structure, and won't serve the purpose of practicing landings nearly as well. A good quality, ball-bearing 46 like he has will do just fine. We're not talking about a huge trainer; we're talking about a 69.5" wingspan, with a flat bottom wing.

A Conclusion?
 

I think between us we've come to an agreement and therefore maybe a conclusion (wow, that must be a first!) :)

It looks like the TT pro .46 will provide adequate power for the Tower Trainer 60.

Bear in mind the following:

Carefully check the balance:
Mark the balance point accurately underneath each wing and have a friend support the wing at the balance point. Check that the plane balances with the wings level (front to back).

You may have to experiment with prop sizes. From the info in Tower Hobbies it looks like 11x6 is a good starting point.

Its going up with the .46
 

Its going up with the .46!

Thanks!

Motor size question
 

I, for one, would like to hear how it goes.

I think that you should be O.K. with this combination.

When I am training new pilots with flat bottom wing trainers, we rarely get over 1/2 throttle. Throttle management comes somewhat after learning to fly a rectangular field pattern, maintain a set pattern in one quadrant of the sky and other goodies like this.

Take care and enjoy your flying.

The Verdict is in...
 

Hey all, just wanted to let you know how it went.
It flew like a bird! Really didnt have to get it above 1/3
throttle while cruising around. We had winds today gusting to about 15mph and the thing was solid as a rock.

I would suggest anyone looking for a good trainer to
get this one. I was using a 10x6 MA prop and it would go vertical up to about 3-4 mistakes high at least.

Thanks again everyone.

Motor size question
 

:thumbup:

Motor size question
 

Great! :) Glad it worked out!

Got me thinking now, my OS 65LA has been giving me trouble, maybe that K&B .45 I've got laying around would do...... :idea: