Author Topic: Quark 2M - Back to cutting innocent trees! (Read 422674 times)

alibodin · « **Reply #405 on:** November 02, 2014, 21:53:38 PM »

Hi,

Having built a Quark has anyone retro fitted an extra set of servos in the wing to add flaps and aileron, is it easyish?

Looking to add flaps to allow crow braking to help me land on the slopes I fly.

Thanks

Alistair

Fred · « **Reply #406 on:** November 06, 2014, 10:33:03 AM »

Hey Alistair,

I am not aware of any retrofitting. :?:
Should not be too hard I think. Cut the ailerons maybe where the servo bay is.
Add a servo on a piece of wood glued between 2 ribs near the wing root.
I would try to put the additional servo as close as possible to the wing root to avoid adding too much weight far from the fuselage. will help with inertia a bit

Another way, might be to install the servo, if you use a mini one, in a cut-out in a rib :?: Might fit. And with a piece of plywood to re-inforce it, should be no problem, and slick once recovered

alibodin · « **Reply #407 on:** November 10, 2014, 19:53:42 PM »

Thanks Fred,

On further thought I think I will keep the Quark as is.

If I get another maybe build it in from the start

Alistair

heli_bee · « **Reply #408 on:** April 12, 2015, 19:12:21 PM »

This weekend saw me test fly my Quark. The winds were 25mph gusting 35mph but the model flew, and flew well.

I ended up removing 35 grams of lead from the nose, moving the CG back behind the the plan position. Not sure where it is set right now but with the wing and tailplane at 0:0 incidence the model will continue in a dive and not pull out.

Martin

Fred · « **Reply #409 on:** April 13, 2015, 14:24:22 PM »

Hi Martin,

Welcome to the forum

Now, that's a nice photo! Like the scheme! Glad you like the Quark and the first flight went well

For the CG, I believe the most extreme I saw, was somewhere between the 2 wing joiners!
If you fly inverted, do you have to push a lot?

heli_bee · « **Reply #410 on:** April 13, 2015, 14:57:09 PM »

Hi Fred,

Thanks for the compliments on the colour scheme. It came about because I was using up lots of odds and ends from my covering box. I haven't done more than repair existing coverings for the last ten years so I was pleased with the result! It can certainly be seen.

As to flying inverted, I still need about a half stick of down elevator to maintain level flight. I will try again in lighter wind conditions and may shift the CG back again.

Martin.

Fred · « **Reply #411 on:** April 13, 2015, 15:19:42 PM »

Hi Martin,

The scheme does look nice, and done with leftovers on top of that! :clap:
Half a stick... Hummm, Is the elevator with the f"flat" profile, or the "proper" profile one? :?:

heli_bee · « **Reply #412 on:** April 13, 2015, 15:35:32 PM »

Fred,

The elevator is the proper profile one - CNC cut.

Martin.

heli_bee · « **Reply #413 on:** April 14, 2015, 09:25:00 AM »

Fred,

With the benefit of hindsight, the actual amount of down elevator movement to maintain altitude when inverted is not that much, when you think about it.
I am currently using 60% exponential as per the plan!

Martin.

Fred · « **Reply #414 on:** April 14, 2015, 10:14:50 AM »

Hi Martin,

AAahhhh OK, 60% expo on the elevator!

Sorry, I think I made a mistake (never updated the values!) but on the article, I said I totally removed the expo on the elevator :oops:
Much sharper response, but you can start by reducing it to 30%

I double check my plan! :oops:

heli_bee · « **Reply #415 on:** April 14, 2015, 10:59:47 AM »

Fred,

I had planned on trying to reduce the expo on the controls once I had got comfortable with the flying characteristics. I will reduce the elevator throw a bit and try 30% expo for the next flight.

Thanks,

Martin.

Fred · « **Reply #416 on:** April 14, 2015, 12:07:30 PM »

Hi Martin,

30% sound like a good start. You should not see much difference, just a bit less push on the stick.
The benefits will be a much sharper response of the elevator, a bit more in "phase" with the rest of the controls if you see what I mean

Let me know how it goes

Fred

heli_bee · « **Reply #417 on:** April 27, 2015, 10:26:17 AM »

Flew the Quark again yesterday. The winds were 10-15mph and occasionally 25° off the slope.
The model flew well with the elevator expo set to 30%. I will reduce it to zero for the next flight.
Everybody on the slope was surprised at the quality of the slow speed handling and the roll rate

With a couple of mm droop on the ailerons the model climbed very well.

Martin.

Fred · « **Reply #418 on:** April 27, 2015, 10:44:41 AM »

Very nice Martin :clap:
I totally removed the expo on mine on the elevator. Much better I think, more "in line" with the rest in the controls for responses.

Glad you enjoy your Quark

alibodin · « **Reply #419 on:** May 03, 2015, 18:04:22 PM »

Whoops, removed too much lead from my Quark and that old adage of to rear a COG one hectic flight with heavy landing was true.

Managed to break both carbon wing joiners, fuz was a little sad and broken. Wings not a mark on them.

Mending fuz was like a 3 D jigsaw puzzle put the balsa bits back in place and hold all square and add thin cyno. Did add some fuz reinforcing inside the fuz. Anyway all fixed and COG is now at about 65mm from leading edge which is very safe.

My question is how long do the carbon wing joiners need to be??

Is 320mm long enough for the front and 260mm for the rear?

If not I need some new Carbon fibre rods!

Feedback welcome, thank you.

Alistair

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