Something simple - small parkflyer QB10H

[solentlife]

Many years ago - I had a marvelous small IC OS-10FSR powered high winger ... the Pilot Models Quick Build series QB10H ...

Pilot produced a series of simple quick builds that covered High, Mid and Low wing versions in IC 10, 20 and 40 engine sizes. Simple, but highly flyable .... they were a delight.

I now managed through friends on these forums to get hold of a copy of the original plans (attached below). I then tiled to A4 ....

The original was built in a combination of Lite-Ply and balsa. My new version today which I shall call QBEE 10 ... is to be in a combo of hardwood spars and foam sheet ... 6mm Depron, 5.5mm Underfloor sheet and 3mm Depron.

Power will be brushless of course, RCTimer with a 7x5 prop on a small 3S pack ....

(Here on front of my profile ME109)



We start :

Having taped the plan together from the tiles ... I first cut out two fuselage sides. The plan calls for highly lightened sides but that's in Lite-ply, so I think full sheet sides of foam are not a problem. These are in 5.5m floor undersheet foam.



Winter is here ... weathers questionable ... so why not revive some of ,y old models !
The Lancaster project is still on - but sorting out bits and pieces to complete the whole. So while sorting and ordering - I can get on with models like this which I have all the gear for.

Watch this space for further posts as I fgo thropugh what should be a simple build. As I vary / modify the plan - I shall try and explain why and what ...

Nigel

[Bill G]

Somehow I passed those QB plans up, at outerzone.uk. I hadn't seen this Pilot series of models. The 10L looks interesting also, as a quick build aerobatic plane. I had come close to starting on their Zlin Aerobat a short while ago. They have a number of Pilot plans there, some that have come close to being started as builds.

[solentlife]

Originally Posted by Bill G

Somehow I passed those QB plans up, at outerzone.uk. I hadn't seen this Pilot series of models. The 10L looks interesting also, as a quick build aerobatic plane. I had come close to starting on their Zlin Aerobat a short while ago. They have a number of Pilot plans there, some that have come close to being started as builds.

They were excellent models far more capable than first look indicated. They have semi-symet wing forms good for aerobatics.

The Zlin Acrobat (20 IC size) - I had that and I can say it was really excellent model. I entered mine for scale comps and she did well.

Anyway ..... on with build .......

Tail feathers ..



Wing ribs in 5.5mm foam ..



Fus formers ready to fit ..



Fus sides marked up for formers ..



Fus going together ..



Insert tail parts ..





Run extension leads before closing up fus ... it will have HXT500 servo for rudder and similar for elevator ...



Top deck on ..





Battery hatch being shaped up ..



Build has now stopped while I skip of to Venezuela on a job for a few days ...

Total time so far about 3 hrs.

Be back as soon as I can !

Nigel

[solentlife]

OK ... phew ! I'm back ....

While away - I considered my plan for wing construction and decided that it was not so good ... too much weight.

So I have now altered my idea and cut a new set of wing ribs. The spars will be 6mm round pine (all I have in my stock). This will make the wing spanwise incredibly stiff and able to stand my style of flying ! The model is capable in original form of real carve the air flying. With foam I want to be sure she'll survive.
A similar 6mm round spar will be inserted into LE to reduce that all too often damage to foam LE we all see ... or I revert to the 10mm 1/4 round .. that will be decided once I lay out the ribs and spars ...

First need to clear my work load (reports) and then it's get on with this little baby.

Nigel

[Bill G]

The pine dowel rod lends itself well to straight wings, especially constant chord. I use it for both main spars and LEs when possible. The 3mm size has really become a favorite for LEs. I'll do anything to avoid forming a sculpted LE, other than for small models.

[solentlife]

BillG ... very true - the trick is to make sure you get a nice straight piece ! Some of the stock in local DIY is atrocious for curves ... makes Gina Lollabridgida look flat ... (for all those younger people Google Gina ... !!)

Anyway ... did a dry run with the dowel for spars and it was not so good .. so back to the 1/4 round 10mm pine. That is straight as die and a single piece top / bottom for whole span and no joints. weight is not so bad .. 2oz for both spars.
The round dowel is still for LE though to save all that shaping !
Wing sheeting will be with 3mm foam sheet ... saving weight and actually because the whole build is designed to show how the scrap box can be used to complete a model !

The TE will be 1/4sq balsa strip, to provide stiffness and good anchor for mylar strip hinges (similar to CA hinges but traditional !). Behind the TE will be 6mm foam backing between ribs to give a bit more depth and security to the TE.

Photos so far :

Here we have the 1/4 round fitted to ribs ....



The 6mm round dowel being fitted to slots in rib LE's ...



Here we are sizing up use of balsa and foam ... as you see the balsa is in pieces from the scrap bin and needs to be joined to make full span ...



5 min epoxy, paper tape, workmate, patience ... we have a TE spar setting joined and straight, held by workmate while epoxy sets ...




The wing so far is not absolutely true .. with my change of materials and construction method - it relies on me doing the final TE and sheeting aided by the workmate to straighten it out. I could build on top of plan but as I say - I am not using same construction format - so would only be a general guide.

The wing will be set into the workmate so that rib TE's are held aligned ... then balsa TE will be glued on ... foam inserts made between ribs to back up and strengthen ...

Nigel

[solentlife]

Wing continues ...

Braced in workmate for TE to be fitted ..



Insert foam backing going in ..



3mm sheet foam being marked out for wing sheeting ..



LE sheeting ready to apply ...



Nigel

[solentlife]

Sheeting of wing ....





Re-inforcements for sertvo mounts ....



Extension servo leads in place before covering ...



Covering will be with Solarfilm / Oracover - continuing the 'scrap-box' ideal. have various bits and pieces of film cover left plus a good size roll of yellow Oracover ... so it will be a Cover of many colours - with a bit of artistic thought - I'm sure I can produce a colourful result !

Nigel

[solentlife]

On we go .... covering, servos and motor ...

Wing covering ...





with my 'signature' ..



Motor and ESC ... (this is overpower - but I wish to really make this model go ... )



General views as I get on with covering ... (tail feathers still to fit anf ailerons .. )









Note that this model is not a trainer ... the wing is a 3/4 symet and the performance of the original on a good 10 IC was amazing .. when I fitted a 20 - it was ballistic ! Hopefully I should get similar. I have left out the dihedral, original had about 5 degrees .... I've also fitted split aileron servos instead of the central torque rod original. The elevator / rudder servos are at the rear of fuselage instead of underwing in fuselage. I've elected to keep the rubber band on wing arrangement to allow easy dismantling for transport....

Power is to be any of my smaller 3S packs from 800 up to the 1800 ... propp is a 7x5 ... motor is approx 200W and use to heave my 600gr ME109 around ...

I have wheels and legs from the ME109 .. but will probably leave of the wheels to give a sport hand launch job ..


Nigel

[solentlife]

So here we go ... QBee ... ready to go













AUW without battery : 432gr, with 1800 3S total = 567gr
Span : 990mm
Length : 735mm
Wing area : 16dm2

Original IC model weight 750 - 800gr ..... so quite a reduction with using the foam and that's even with the heavy pine spars in the wing.

The motor is a RCTimer 200w job ... propped down with 7x5 ... Turnigy Plush 30A ESC ..... 4.5gr servos on ailerons and 5gr on Elevator / Rudder.

FrSky gear in Flysky / Turnigy 9X radio.

Initial motor runs in hand ... Blimey ! Reckon sge may go vertical !!

I decided to leave of the wheels .. that would bring her up nearer to original weight I reckon if fitted.

CoG ? This is the real surprise - spot on the main wing spar , same as original specification.

Now I have just to wait suitable day for the maiden ...

Nigel

[solentlife]

Today was get-together to celebrate end of 2012 ... so we all brought a few models ...
On leaving home - weather and wind was fine. So I took along my usual Cessna, Lanyu T45 and the HK 540 racer. The Cessna is always my first in the air plane to a) get fingers working, b) to test the air.

Arrived at site ... wind was starting to gust and I put Cessna in air - it was not nice, wind was gusting by now 0 - 10m/s ... which meant she was all over the shop with me pulling sticks all ways to stay reasonable.
Others were finding similar and it was debatable what to do next ....

Well - the Qbee used to punch through stuff when I had the original but with a 20 Ic up front. I hoped that using a good motor here would give me similar.

Vilnis launched for me ... and she immediately shot back in the wind and I ended up fighting a model that all she wanted to do was climb and climb !!

http://youtu.be/SxIqNAf7XTM

No amount of down trim could fight the wind - so it was close throttle and see if I could get her to put nose down and start a glide ... once I had that ease on power and try to keep her reasonable to come in for a landing.

She survived less a broken prop and cracked fin seating.

Yes - a less than satisfactory maiden, but she survived proving she will fly well.

Modifications ? I've added a couple of degrees more downthrust to motor. I will alter the wing incidence as I think I have too much +ve angle causing her to balloon seriously ....

Pleased ? Yes that she went home in one piece and I have good idea of whats' needed to sort.

Nigel

[solentlife]

Being away from home and not able to fly - gives you time to think over lots of stuff that usually would get pushed aside due lack of time ...

The QB10H and it's maiden.

As already posted - I'm sure that a combo of too much wind, elevator few too many clicks up allied to a wing incidence possibly too much - all of which are basically adjusted now .... I have decided to add wheels ... the original I had flew great with them - so no reason why shouldn't now.

Construction of landing gear for such a model is actually not hard. My way is to use the 2mm control rods that Hobby King sell in packs of 10. they are strong and threaded end that is great for securing wheels ! For a model this light, I would use 2. The top end would be bent so it faces back with last cm or so bent again to be across the fuselage. This skewed Z would allow screw clips to secure and stop leg from turning. Being a foam model and would need a ply plate to carry these - I would not make the leg pin INTO the model vertically .. That would need a block and weight.

I hope that addition of the wheels would also help tame her for wind etc. That extra useful weight and also ability to RoG ...

Nigel

[rcers]

Very nice. One question are the ribs worth it? I have just gotten into the habit of using a spar and wrapping around that. Works for me.

I too like the ROG benefit in this size plane - great work!

Mike

[road king 97]

Question Nigel ,i have never tried covering foam with any kind of rc covering ,how do you do this with out melting the foam ? joe

[solentlife]

Originally Posted by rcers

Very nice. One question are the ribs worth it? I have just gotten into the habit of using a spar and wrapping around that. Works for me.

I too like the ROG benefit in this size plane - great work!

Mike

Yes I think they are ... I was reproducing as close as possible the original and that had the wing ribs noticeable in the covering.
The only real deviation from original is the lack of 'lightening holes' in the fuselage as its foam instead of Liteply ...

Nigel

[solentlife]

Originally Posted by road king 97

Question Nigel ,i have never tried covering foam with any kind of rc covering ,how do you do this with out melting the foam ? joe

The film doesn't need great heat to activate. The film used here is Hobby King Yellow and the stripes etc. are Solarfilm I have left over from the 1980's !! Yes seriously !

Main thing is to make sure you seal down edges ... then just use the heat gun wafting it carefully over the structure..... shrinking the film. To apply the stripes .. use cooler iron setting.

No melt of foam or anything ...

Nigel

[solentlife]

Went to invitation fly at Kuldiga today ... took the QBee 10 with me ... after the last terrible try at flying her - I'd altered a few settings on her ...

Vilnis launched her and away she went ... had a bit of a fight trimming her but once trimmed - she proved to be every bit as good as the original I had many years ago ...

24-02-13 Qbee 10H Kuldiga

One of my more successful scratchbuilds ...

Nigel

[solentlife]

Today took her out again ... WOW !! I hand launched and she flew of as true as a die ...

This foam / electric conversion is proving to be an absolute gem. I'm still sorting a few little items but today gave her a few tests ... inverted had no vice at all ... roll rate good and can be reasonably axial ... loops big or small clean ....

Really enjoying this 'rave from the grave' ....

Video to be uploaded shortly once processed ...

Nigel

[solentlife]

Video as promised .......

26-02-2013 own hand launch

Nigel