[Even Later In The Day]

Posted by Peter Miller on 25/05/2020 21:05:13:

Hi Mark

The CG should be at 25% of the chord back from the leading edge.

Thanks Peter.

I have balanced it "approximately" on the main spar, I assumed that was where it should be as that seems normal with most models. I say approximately as I just use the fingertip method which I'm guessing isn't all that accurate. Looking at the plans again, 25% of the chord from the L.E, would put it about 1 centimeter forward of where it is now. I have read the dire consequences of an aft CofG today, would that much difference make it so unstable in pitch?

The symptoms certainly suggest an aft CofG

BTW, I checked my elevatorthrows, function, end points and expo but all seem to be OK.

Think its time to invest (or make) a proper CofG jig.

Cheers

Mark

[Even Later In The Day]

Hi all, Just when you thought it was all over lol!

So I finished the build in March this year (2020) but then the lockdown happened and our club field closed, I never got the chance to fly Ballerina.

Then today, following the government and BMFA guidelines and beautiful weather, i grabbed the opportunity to maiden her. I always fly my own aircraft for the maiden.

I worked hard to get the C of G right and I thought I had, nose down tendency when fingers placed on main spar position, model upside down with battery installed.

So I took off.........fairly quick in to the air but straight away I new it it was too pitchy, very hard to control when ever I applied elevator. I gained height and levelled off and found with no pitch inputs she flew very nicely, quite nippy too.

I tried to do a few practice approaches, wanted to get her on the ground as soon as possible but it was clear that my work was cut out to avoid taking home a bag of splinters.

Anyway, did my best, suppose the lack of flying over the last few months didnt help. Ballerina's wheels hit the ground pretty hard and she bounced back up in the air about 6 feet. By this time she had stopped flying, fell to the ground and cartwheeled a few feet.

Happily though, the only casualty seems to be the prop and maybe the undercarriage a bit bent........ good job it wasn't a not so cheap ARTF!

My Ballerina has an AUW of 2.2KG, I think i probably put about 200g of lead in the nose to balance her. I have set all the controll throws to the initial recommended settings.

Does anybody have any views on this? my first thoughts are with the Centre of gravity and I need to invest in a proper jig to ensure I have this right. What else could it be?

I am keen to get this sorted cos I'm sure when it's right she will be a great plane to fly.

Cheers

Mark

[Even Later In The Day]

Posted by Peter Miller on 02/03/2020 21:02:51:

Posted by Mark Ellis 1 on 02/03/2020 18:59:14:

Its Finished.

Comes in at an all up weight of just over 2KG but I am going to have to add a fair chunk of lead up front to balance her correctly.

Overall, I enjoyed this build, learned a lot and produced a good looking model. Can't wait for the maiden.

Thanks for the help along the way Peter.

I am alwys glad to help.It is a pleasure to see another Ballerina

For the last few months, all I can hear ringing in my ear is Nat King Cole's version of "Ballerina". I can imagine flying Ballerina with this music playing in the background!

[Even Later In The Day]

Its Finished.

Comes in at an all up weight of just over 2KG but I am going to have to add a fair chunk of lead up front to balance her correctly.

Overall, I enjoyed this build, learned a lot and produced a good looking model. Can't wait for the maiden.

Thanks for the help along the way Peter.

[Even Later In The Day]

[Even Later In The Day]

My version of Ballerina is almost finished, photos tomoz. The only thing that I am not happy about is the windsheild. I made a very basic one but have not glued it in yet. I only have tomorrow night to get it right/better. This is where experience would have been an advantage, this is only my third build.

Any advice will be gratefully received.........this is directed at you Peter as I'm sure your the only one following this thread lol.

Cheers

[Even Later In The Day]

So I am coming to the end of this build, Ballerina WILL be finished in about 10 days time for our clubs annual build competition. Very little to do now. I will post pics of the completed model.

I have a question though about the undercarriage.

I managed to bash the piano wire into shape and they fit in to the wing nicely. However, I was unable to give the wire the rake as shown in the plan, they are very slightly forward. Thus the wheels will probably be approx 1" aft of the plan position. Will this be a significant problem when I come to maiden Ballerina?

Many thanks

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Just an update..... I'm taking my time lol, but the wing is almost finished. I practically have an ARTF kit now and am focusing on the build now as I want to finish it for our annual build competition at KADMAC in March.

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[Even Later In The Day]

Posted by Mark Ellis 1 on 27/10/2019 16:38:50:

So I haven't gone away, I'm still building my Ballerina. As you can seeI have started on the Port wing and hoping to put many more hours in to the build now the dark nights have arrived.

Progress was slowed following a holiday to RC Hotel in Corfu plus a little experiment in Gyros ( which cost me a few bob) and a repair job or two on a couple of my other models lol.

Mark

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[Even Later In The Day]

Posted by Mark Ellis 1 on 09/09/2019 22:18:40:

Posted by Mark Elen on 09/09/2019 20:57:32:

Looking good Mark👍

Mine are not epoxied in. Just saddle clamped.

How are you liking wing building? It’s my favourite part of a build.

Cheers

Mark

I do enjoy my building wether it's the wings, fuselage or any other part of the aircraft. Some people get satisfaction from completing the daily crossword, I get mine from having something I made that actually gives pleaure after it's completed.

I have had a good look at your build Mark by the way.........quite impressive.

[Even Later In The Day]

Posted by Mark Elen on 09/09/2019 20:57:32:

Looking good Mark👍

Mine are not epoxied in. Just saddle clamped.

How are you liking wing building? It’s my favourite part of a build.

Cheers

Mark

I do enjoy my building wether it's the wings, fuselage or any other part of the aircraft. Some people get satisfaction from completing the daily crossword, I get mine from having something I made that actually gives pleaure after it's completed.

[Even Later In The Day]

Posted by Mark Ellis 1 on 09/09/2019 20:29:27:

So work on Ballerina is going at a slow pace but I don't have to worry about being the first one to finish lol. This is progress so far on first half of the wing.

Looking forward, as far as the undercarriage goes, apart from the undercarriage saddles has anyone used apoxy to secure the undercarriage struts. Is this necessary?

As the nights draw in I expect to have a lot more time during the winter months to finish this project in time for our Clubs model building competition!

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[Even Later In The Day]

Posted by Tom Sharp 2 on 20/08/2019 01:02:25:

Mark, click on quote to reply to an individual post.

Cheers Tom!

[Even Later In The Day]

Hi All

First of all, I would like to thank those who have contributed their thoughts and ideas so far, its much appreciated but this being my first time on a forum, i don't know how to reply to individual posts from forum members.

I have started work on the starboard wing, not glued much yet cos I want to see how things fit together and sort out any difficult bits which can be done easier and better (or more correct) early on in the build. An example of which is placing the mounting supports for the aileron bellcranks to the relevant wing ribs. I decided to keep to the original plan and use 1 servo for both ailerons.

From what I have read, I understand R1 & R1a should be glued in position on the first half of the wing 90 degrees to the spar, as are all the other ribs. The angle when the two halves of the wing are joined is created by R1 and R1a on the second wing half (port wing) when they are joined together. Is this correct?

I will post pics as my progress with the wing continues.

Thanks

Mark

[Even Later In The Day]

So this is as far as I have got. I have cheated this time and bought the woodpack, which has saved a lot of time.

I am building it as an electric version as you can probably see, I have constructed a battery hatch which detaches between F2 and F5. The battery goes through F2 all the way forward to F1. In my limited experience I have found electric models to be tail heavy! The speed controller and servos are already installed. This is a brief description of my progress so far, I have started work on the wing this week so I may well put some more pics up as that progresses.

One question that springs to mind right now is should there be any side thrust or down thrust when fitting the motor, its not been discussed much in the forum?

One final note tonight.........I make many mistakes and am a bit of a botcher but I enjoy building my aeroplanes and the 3 planes I built so far have all flown and still intact

Comments and questions very welcome

Cheers

[Even Later In The Day]

Hi Chaps. I Also was Given the Ballerina plan from an old magazine quite recently. I decided to go ahead and build it as I like open cockpit sports planes. This is my third project. and have spent a lot of time reading threads from various builders from which I have gained a lot of good advice.

I wondered how much interest there still is on here as my build is nearing halfway completion.........I may have questions as I consider myself a Newbie?

Cheers!