I purchased this plane and was quite impressed with the stock set up but I always planned to upgrade the motor and ESC. This plan was brought forward when the motor came off its mount mid-flight and I had to use all my aero-skills to glide back into a very sudden and strong headwind, just clearing the top of some very tall timber.
Anyway, enter the turnigy 2730-3000 and HK 18A ESC and this thing rips! It was responsive at high speeds on the stock motor but now it feels like its on rails. Vertical flight, speedy barrel rolls and fast loops galore. Impressive, fun and highly recommended mod...

Micro Fournier RF-4D RC upgrade test Flight (3 min 54 sec)

My only problem is the wing flex which I've had to be wary of while flying hard. Can anyone suggest where and how to install them? Should I make small incisions with a blade and wedge them in?

'Them' being carbon rods....

I'd say, yes. If you're concerned about the wing flex, gluing in CF rods will help that a lot.
Without seeing your plane, I'd say go for the thickest part of the airfoil, unless there is already a natural seam somewhere.
And install it on the underside of the wing, so that you don't interrupt the smooth airflow over the top of the wing.
You don't need to go the full length. I'd probably go about 2/3rds length.

Or, of course, you could fly it like the power glider it is.

I had a Cox Sportavia way way back in the late 70's, with the 0.049 engine, and that was a Fournier RF-4 I believe. I also have plans to scratch build a large one, which I've been wanting to do one of these winters. They're nice planes.

Peter Rake.

I have one and is not a glider! Even with the original motor it flies more like a pylon model. It's fun to fly if you like things that go fast and do the occasional outside snap roll.

Funny thing is, it looks like it should glide. It's a fairly nice looking plane except for the cowl.

Mine required a lot of work to get flying. The push rods were music wire and the hinges were fairly heavy foam. The pushrods bent and the tail surfaces barely moved etc etc! A day's work got it flyable but it's not what you'd expect looking at it.

Pete

Originally Posted by builderdude

I'd say, yes. If you're concerned about the wing flex, gluing in CF rods will help that a lot.
Without seeing your plane, I'd say go for the thickest part of the airfoil, unless there is already a natural seam somewhere.
And install it on the underside of the wing, so that you don't interrupt the smooth airflow over the top of the wing.
You don't need to go the full length. I'd probably go about 2/3rds length.

Thanks, missed your post but got it sorted. Waiting for a test flight with a 3S battery. It seems to cook the 18A ESC pretty easily so I'll have to back off the throttle (but I'll give it a few full thrusts )...

PeteSchug - No, it's not too much of a glider although it is a good slow flyer if you just want to cruise... but at high speeds it's responsive and smooth, even more so with the upgrade.

Hi I am thinking about buying this plane, but I have a question. Would I be able to fly it with these batteries?

http://www.hobbyking.com/hobbyking/s...dproduct=21331

Would I get at least 15 minutes from them if I fly it slow?

Actually this brings another question. Can this thing be flown slow? Would it stay level with let's say half throttle of slightly more?

Thanks,
Luca

A 200-325mah 3s battery and a better prop, like a 4x4, 5x3," or 4.5x3or4" GWS does wonders to this one. I needed a different 2mm prop adaptor for the GWS.
My stock esc worked fine after switching to high timing, and the 17 gram, 2000kv stock motor comes alive.. In fact, that motor with the 5.25x3.5" prop from the UMX GEEBEE and 3s, is killer on my 5.5 oz sweet stick.. over 10 oz thrust!


Wing flex was an issue, but it never broke.

Originally Posted by lunobili

Hi I am thinking about buying this plane, but I have a question. Would I be able to fly it with these batteries?

http://www.hobbyking.com/hobbyking/s...dproduct=21331

Would I get at least 15 minutes from them if I fly it slow?

Actually this brings another question. Can this thing be flown slow? Would it stay level with let's say half throttle of slightly more?

Thanks,
Luca

It is really tight with a 500mah 20c 2s.. I get 10 minutes.
Yes, level flight at around half throttle. Use rudder in turns to keep wings level as the craft will tend to loose lift quickly. I mixed rudder with aileron for great results.
This is NOT a glider and does not carry energy once the throttle is cut, so you will carry half throttle to the short final for landing.
Balancing the prop helps.
One should loosen all controls BEFORE moving the servos.
It is best to remove the control rods then FLEX the control surfaces hard in each direction for ease of servo movement. (2 gram servos)
The elevator pushrod needs a fix to keep from flexing for you will have inconsistant elevator.

Originally Posted by MikeRx

It is really tight with a 500mah 20c 2s.. I get 10 minutes.
Yes, level flight at around half throttle. Use rudder in turns to keep wings level as the craft will tend to loose lift quickly. I mixed rudder with aileron for great results.
This is NOT a glider and does not carry energy once the throttle is cut, so you will carry half throttle to the short final for landing.
Balancing the prop helps.
One should loosen all controls BEFORE moving the servos.
It is best to remove the control rods then FLEX the control surfaces hard in each direction for ease of servo movement. (2 gram servos)
The elevator pushrod needs a fix to keep from flexing for you will have inconsistant elevator.

Hi MikeRx, thanks for your reply.

When you say that the 500mah battery is tight, do you mean space wise or weight wise? If it is a space problem, can some foam be carved to make some space?

The push rod issue seems concerning. How did you fix it?

Thanks,
Luca