|Construction / tuning / conversion: (May 2010)
Since I saw on YouTube some great flying of a converted stock Easy Cub plane ... and here is my flight (sorry the camera is no good), but still.. ok!
of Multiplex in late 2009 I always wanted to build one too. See the video below: I enjoy flying this plane! It is great fun!
However, surprisingly, Multiplex issued under the name of FunCub just that sort of plane I wanted to build (and as seen in the video). The good effect of the new
issue was, that most of the online stores greatly reduced the prices of the now "old" Easy Cub - so I still decided to go for that model and do the conversions myself.
Construction / tuning / conversion:
Lets start: the box contains the usual MPX quality stuff - it is complete and undamaged from the transport.
In addition I ordered some super-light 120 mm tyres - see on one of the pictures the size difference!
As the original brushless motor set of Multiplex includes a 28 mm dia outrunner I was immediately trying out my new
motor (35 mm dia) - and to my surprise it fits even to the holes in the motor mount - no changes necessary! That was :-) !!
In addition I tried to but together the fuselage with the motor mount - even there I was surprised too
because the motor turned freely without that I will be forced to carve out from the elapor foam!
So - all in all - the motor chosen was the right one! GREAT!
The motor mount was glued in both halves of the fuselage (following the manual). Ample glue!
Next I took care of the wings - the addition of ailerons and flaps:
On the top of the wings the rudder size of ailerons and flaps is marked, so it was not really difficult to make a decision. Just take a sharp knife and cut slowly through
the foam (the full length of ailerons & flaps first, then cut out the sides. Then divide the flaps from the ailerons.
The flaps get hinged by strong tape from the bottom of the wings! They need to have max. throw only downwards. The ailerons got hinged in the same way but on the
top of the wings. In order for the ailerons to be able to give enough throw downwards I sanded away a few mm in an angle on both the wing and the rudder.
Servo installation in wings:
On the bottom mark the servos - approx. 5 cm inside from the corner of the rudder cuts and in the center of the rudder! Mark the size of the servos (dont forget the arm
needs more space to freely move. Check the length of the servo extension cable (and then either use a pre-fabricated one) or - as I - do it yourself! (I do not really like
this work... but....). ATTENTION: if you use a V-cable to connect both flaps servos on one channel (as I do) then you need to have both servos looking in the same
direction - this is different to the ailerons, who look the opposite direction.
The channel for the servo cables I cut (burnt out) 2 cm away from the main CFK support rod - with a soldering pen!
Fixing the rudder horns is quick. I had still some MPX originals from my extra supplies - so I used them. Normal installation for the ailerons, however, for the flaps I
turned the horns outwards (towards the back of the plane). Why? To give them enough space for a 90 degree throw!!!!!! :-)
Now I turned towards the fuselage and finished it as per manual!
With two little exceptions:
1) I replaced the normal elapor main wheels with some 120 mm dia "Tundra Tyres" - super lightweight!
2) and - as the Micro wheel supplied in the stock for the tail looked funny now, I used a 50 mm dia tyre instead.
as this new tail wheel was much bigger I had to bend a new steel support for it (same as the original, just bigger). Not a big deal.
And last but not least - the finishing:
Here I used my usual method for the windows indicated in the fuselage: sanding with 600 paper, then using an Edding permanent marker pen (blue for the window
"glass" and black for the frame around (also the indicated door). The stock decals I cut out (not all of them) and fixed them as I imagined - and some other
"Euro-Fighter markings, left over from a previous project).
The programming of the RC system I did as suggested. The ailerons I opted for maximum throw (upwards) and 50 % downwards - as a first setting, the rest needs
to be adjusted when flying.
And finally the balancing point was achieved by sliding the battery to a position which is almost under the wing.
Total building time: 8 hours and 30 minutes including finishing and programming.
NOTE: No - not in one go. That is impossible with my job and my family. I had to cut my time in a typical Hungarian way - in thin "salami" slices. My time in the garage
(my workplace for my RC-hobby) was limited to slices of about 30 to 60 min max!
Now, the plane is awaiting its first flight (... I would have had time after the picture taking, however another thunderstorm came through and.... my EasyFunCub had to
stay in the hangar.
Flight Experience: - First flight date: May 23 2010
The conditions were ideal during the first flights, light breeze, great cloudless sky. The first start I made from hand without flaps. Just full power and a strong throw!
Wow.... the EasyFunCup immediately took her nose almost vertical! I hardly could manage to to keep the plane balanced and it was a challenge to fly her around to
land... which we did manage.
So, the angle of the motor downwards was corrected (increased), the battery came forward by 1cm in the fuselage and I programmed a 5 % negative throw on the
Second try, better, actually during motor stop sailing it was now perfect - but not perfect with the motor yet. So again the same procedure as before - landing and
some adjusting (now elevator at -10 %) and a little more down angle at the motor mount (great that Multiplex build them in such an adjustable way - thank you). In
addition I replaced the propeller with a bigger one (first I flew a 10" x 5") with a 11" x 5".
Third flight: perfect! This one I started first time from the (still muddy runway - from all that rain). During this flight I also tried out the flaps! Wow - the plane almost
when ballistic when I used the flaps - so additional programming was necessary - see comments below (of course this was not found out just like that but I tried out
the optimum during further flights).
Other flight comments: to turn around the plane I have to use ailerons & rudder - just ailerons does not work properly and quite some hight is lost. Which I
programmed for the forth flight - on a switch, so that when I would like to fly a role, I can switch off this function. Ad role - that is another weakness (I should have
known, but it was my planning oversight): due to the wings V (which is quite big - because the original plane is a trainer) the roles do not come great!
So I decided to do some further modification and possibly eliminate totally the "V" - as I have done with the smaller PicoCub. Lets see - another project for rainy days.
Ailerons-rudder: 30 % addition of rudder to help the ailerons (switchable)
Rudder - nothing
Motor - elevator: 10 % down when motor on (as of 50 percent motor power)
Flaps - elevator: elevator down up to 50 % (gradually - 5 point curve with throw increase in 10 % steps) following the flaps throw (maximum: 90 degree down !!!).
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