Hamilcar - a complete rework!

[CHELLIE]

Dang, You sure did a good Job of Hideing those little Ailerons LOL, If this was my Plane, I would Cut the ailerons and make them full lenght i would continue the same hinge cut right to the middle of the wing, Now i know i will have great control over the plane, due to prop wash helping me out, i know it wont be scale like, but it will fly IMHO with a 25% CG from the leading edge of the wing, Make a foam profile plane the same size as this plane and test its flight worthiness. that will give you a lot of feed back, Take care, Chellie

[BBCorvette18]

I agree

[eye4wings]

It is much easier to see the HUGE amount of incidence the mainplane has on the glider drawings than the powered version.
I am often amazed at the difference between what the situation was for the 1:1 compared to what is practical for our scale models.

Allow that much angle on the model and you'll need full down elevator just to keep her level!

Hopefully you have about +1.5 degrees compared to tailplane Quorneng?

[quorneng]

eye4wings
I too have noticed that models tend to operate at much lower incidence than full size.
I believe a scale model wing actually stalls at a slightly higher angle than the full size but its efficiency at higher angles of attack is very poor, hence the low angles used by models.

Although my Hamilcar does have less than scale incidence built into the fuselage I suspect it is still considerable when compared to the camber line of the thick scale wing section.
This may also be part of the reason why it needs its CofG well forward.

The way the wing is now mounted with rear spar hold down bolts it is possible to shim up the trailing edge a small amount if required.

[stuart]

LOL!!!!!i only just joined in the conversations between you and chellie regarding the ailerons....i thought the flaps were your ailerons...lol..to funny.the job of camouflaging the wing tips with tape and paint is done beautifully. now i don't have a clue what all the conversations were about as many planes have the same flap /ailerons layed out just like yours. to give you an even better laugh at me...i thought the flaps were the little wing areas that go along side the fuse.....dooooh, as soon as i saw your drawings everything became soooooo clear...lol. seriously funny,i was blind ,but now i see.


she'll fly great! looking forward more than ever to seeing the finished build.

[quorneng]

Slowly putting all the pieces together.

I had forgotten just how big it is!
The centre section is load bearing so it will be fully skinned in 3mm Depron apart from a small slot to enable the elevator and rudder servos to be plugged into the radio.
As the wing is removable for transport the long 35mHz aerial has been taped to the underside of the RH wing, however field assembly will not be a 2 minute job as apart from the wing the undercarriage has to be bolted in place as well.

[eye4wings]

Have you got plenty of washout on those wings?

As you can no doubt imagine, there is a lot of disparity between the air speed of the wing tips with any rudder operation with that type - and the square cut tip is a common feature of wings designed for planes required to snap roll because of their lacking any smoothing of the tip vortices which can spread a tip stall down the whole wing almost instantly in any overload situation.

Washout is therefore a very wise precaution to take - in fact not to include any is asking for trouble.
I posted my suggestion for the inclusion of washout earlier in the thread.

[quorneng]

eye4wings
The Hamilcar has no washout built in although the flaps and ailerons are rigged with a slight progressive washout effect.

All my big Depron wings have been built 'flat' even the 2.1m scale Libelle one.
They all certainly drop a wing quite readily at the stall but all recover promptly with no hint of a spin developing.
The only real difference with Hamilcar is the inertia of the two wing mounted motors although compared to the total span they are really close in.

Provided the CofG is far enough forward I think it should be ok anyway we shall soon see!

[eye4wings]

The quick recovery is probably because of the light wing loading.

If you are used to the occasional surprise and recovery routine then fine, but I would prefer to have a more forgiving model myself. Maybe that's my age talking but I thought you were doing this revamp because its flying characteristics left too much to be desired.

Best of luck!

[quorneng]

The Hamilcar complete - for about the third time!

With a 2200mAh 3s it weighs 32.3oz giving a wing loading of 7.5oz/sqft.
The CofG is exactly on the main spar which puts it at 25% of the mean chord.
With at good 120W/lb it has (on paper at least!) all the necessary to fly.

I just need the right place and weather to try - again!

[xmech2k]

Looks great! Break a leg!

[eye4wings]

Well, the weather hardly looks inviting just now! Frost and clear skies this morning but rain and then snow forecast over the weekend... the sort of weather for getting started on the next project in the cozy confines of the workshop!