Multiplex Fun Cub - flap servo question

[pixeldixel]

Have a question regarding the Multiplex Fun Cub build. Sorry if it is a “duh” question but I just need more clarification on this issue:

This is regarding the setting up of the Flap servo.

The manual states that we should set the flap servos to “neutral” and fit the control arms at 70 degree position before securing them to the wing. My question is, to achieve more flap throws, would it be more logical to set the servos to a maximum throw and fitting the control arms at 70 deg; instead of setting it at “neutral”?

Are there any negative set backs for using this setting?

I am using HS65HB for that function.

Looking forward to your kind inputs.

Thanks in advance! =)

[joe yap]

Some pictures of the instructions will help. As we can't really relate exactly what you mean without seeing how the flaps are being setup.

Generally, you would want to start the rigging with the flaps in stow position, meaning fully up and with the servo set at neutral, as this is the safest position with getting the servo stalling and flaps not in proper stow position.

You can alter the throws mechanically later, by using changing the positions of clevises that atteches the pushpull rods to the flap control horn. You can also fine tune the throws later with your computer radio.

[rt9]

Halo Neighbour!!

"..The manual states that we should set the flap servos to “neutral” and fit the control arms at 70 degree position before securing them to the wing. My question is, to achieve more flap throws, would it be more logical to set the servos to a maximum throw and fitting the control arms at 70 deg; instead of setting it at “neutral”?

my understanding of your question .. and hopefully correct explanation :p

1. set servos to neutral is logically correct..
it is normal to connect the servos to Rx or to a servos tester to get it to neutral position before we mount the servos.
for example, i ever bought a Tahmazo servos which is delivered with the servo arm set at one end of the throw for easy packing. until you power up the servo then it will revert to its neutral position.

2. fit the control arm at 70 deg position.. also logically correct :p
as flaps move more in one direction (down flap), fitting the control arm at certain deg (not center as to the neutral) will allow more efficient travel of the servos arm in one direction, resulting more throw of the flaps.

3. you can refer to your mini Graphite to have a better illustration :p
of how the servos arm is not fitted at neutral of the servos.

4. or see photo link below.. which may not show exactly 70deg off..
the servo arm can be more to 7 or 8 o'clock.. so that the servo travel can be efficient and delivering the throw by moving from 7-8 o'clock to 3 o'clock.
the servo rarely move clockwise (in this case) except for reflect setting maybe move a little to 7.30 or 8.30 o'clock.


==
picture link from bvmjet..

Flaps in up position:


Flaps in down position:

[pixeldixel]

Dear Joe & neighbor,

Thank you for your explanation. I have enclosed a snippet of the instruction manual and an illustration to give you a better understanding of my query.

[joe yap]

Okay, I get what you mean.

The setup recommended in the manual is mainly based on most radio's flap function itself. In 'ACRO' mode of some radio only allows the flaps to go either to stow or deploy position. The servo should be in neutral position when the flaps are stow. When the flap is activated by the switch, the flaps will only have 1 preset deploy position.

In GLIDER mode, the flaps will be used for camber changing (downward deflections), and reflex ( upward deflections). As such, the servo should also be rigged at neutral, with the flaps stowed and as such, the servo can travel on both directions.

For my Dash-8 and my Pilatus Turbo porter, I deviated from the radio's recommeded setup for flaps, using the GLIDER mode, to exploit the 3 possible flap positions. I deliberately rigged the flaps in stow position, with the flap switch in upward position (reflex). So with the switch at neutral position, my flaps are rigged at take-off configuration. With flap switch at down position, the flaps will deploy to maximum deflection for landings.

If your radio function only allows 2 possible flap positions, stick to the recommended setup from Multiplex. Anyway, with the servo horn offset at 70 degrees, it has already increase the flap throws.

[pixeldixel]

Okay, I get what you mean.

The setup recommended in the manual is mainly based on most radio's flap function itself. In 'ACRO' mode of some radio only allows the flaps to go either to stow or deploy position. The servo should be in neutral position when the flaps are stow. When the flap is activated by the switch, the flaps will only have 1 preset deploy position.

In GLIDER mode, the flaps will be used for camber changing (downward deflections), and reflex ( upward deflections). As such, the servo should also be rigged at neutral, with the flaps stowed and as such, the servo can travel on both directions.

For my Dash-8 and my Pilatus Turbo porter, I deviated from the radio's recommeded setup for flaps, using the GLIDER mode, to exploit the 3 possible flap positions. I deliberately rigged the flaps in stow position, with the flap switch in upward position (reflex). So with the switch at neutral position, my flaps are rigged at take-off configuration. With flap switch at down position, the flaps will deploy to maximum deflection for landings.

If your radio function only allows 2 possible flap positions, stick to the recommended setup from Multiplex. Anyway, with the servo horn offset at 70 degrees, it has already increase the flap throws.

Thanks a lot Joe,

Have a much clearer picture now. That was what i was asking. Found it a challenge not being able to express my issue in writing.

And thanks bro rt9 for trying to explain to me.
- kindly let me know when is a good time for me to return your battery.

[VinCopter]

I’m using the three positions flap switch on my JR9XII.
First pic show the setting on my radio for flap.
Second pic shows the normal position which is full up.
Third pic shows the mid position.
Forth pic shows the full down position, about 83 degrees.

This is the maximum throw that I can get, think that should be enough. The elevator setting will be set after maiden.

[rt9]

:p his radio can do more !!

you can either fixed then flap to positions like VinCopter or..

i uses Aero mode to fly my gliders, as such my flaps are on a variable knob/slider.

some flyer use the Glider mode and use the throttle stick to control the flaps as brakes.

anyway deem comfortable for deploying the flaps

*neighbour.. sunday then.
I will be flying off and return on Sunday.

[pixeldixel]

I’m using the three positions flap switch on my JR9XII.
First pic show the setting on my radio for flap.
Second pic shows the normal position which is full up.
Third pic shows the mid position.
Forth pic shows the full down position, about 83 degrees.

This is the maximum throw that I can get, think that should be enough. The elevator setting will be set after maiden.

Yeah I agree with you. 83 degrees should be more than enough for a very slow landing approach.

I just find it wasteful because the upward throw is totally prohibited. Asked some guys from RCG and some of them mentioned that they also felt that "Neutral" is the wrong wording used in the manual.

Since you have already glued in your servos and since you are able to achieve such an angle, i guess it should do just fine. when do you intend to maiden her? =)

[pixeldixel]

:p his radio can do more !!

you can either fixed then flap to positions like VinCopter or..

i uses Aero mode to fly my gliders, as such my flaps are on a variable knob/slider.

some flyer use the Glider mode and use the throttle stick to control the flaps as brakes.

anyway deem comfortable for deploying the flaps

*neighbour.. sunday then.
I will be flying off and return on Sunday.

Yeah. Many ways to deploy flaps. Will probably stick to the setting that Joe uses with his Dash 8 - One flap setting for take off/slow flying; and one for bush landings.

[VinCopter]

Fix up the tail feathers last night, left mounting the motor and finish up with the radio settings. Looking to maiden her Thu or Fri evening, provided weather permits.

[pixeldixel]

Fix up the tail feathers last night, left mounting the motor and finish up with the radio settings. Looking to maiden her Thu or Fri evening, provided weather permits.

aight. let me know and i will be there

[VinCopter]

Non of my current motor can fit into the Fun Cub. Guess have to going shopping tomorrow.

[kiply]

Hi, can the bros here with the Funcub kindly let moi know where to get hold of one? I asked one of the LHS normally stocking MPX stuff and they said stock may be coming in later but no idea when. Thanx!

[VinCopter]

My friend pre-ordered about some time, he help me get the last kit. Guess you have to wait, order from oversea.