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Hi Geoff, and anyone else planning to build L'il Cub, I have had similar experience on my maiden flight with regard to the inability to turn right. My first flight nearly ended in disaster. My c of g is as per the plan. My ultimate solution was to increase the aileron throws and mix in about 30% rudder. I would also strongly suggest both down and right thrust especially with low kv motors coupled to larger props. As per my previous post, the offset hinged flaps are really powerful and enable slow, fully controllable flypasts and walking speed landings even though my L'il Cub weighs 2.2kgs. The very soft and light 5inch Tundra II wheels also prevent those bouncy landings. I am now enjoying my model with the small but effective changes in place.

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THis is very interesting. As I have said mine performed with no problems as per the plans.

However it seems that with a design with what might be described as pretty extreme performance is obviously far more sensitive to very minor variations in construction and it could be that my variations were luckily in the right direction.

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Posted by Geoff S on 22/08/2020 14:42:22:

I've just ordered the CNC parts from SLEC and building will commence shortly (I've hot to drag myself out of lethargy somehow! ).

I've been studying the drawing and article in the magazine as well as the PDF files Peter so kindly sent me and one thing ín particular puzzles me - why are the flap servos installed as mirror images thus needing a reversing Y lead to connect them to a single receiver channel? Is there any reason why I can't have the servos oriented the same on both wings (ie with the arm pointing (say) port) rather than with them both pointing inwards?

It seems to be a common issue. My Multiplex Fun Cub is the same and I've connected the flap servos to separate receiver channels. As I had a spare channel anyway it wasn't a problem but it seems odd to me.

Geoff

Hi Geoff,

I've been looking on the SLEC website for the kit but can't find it? What do I search or did you have to ring them and if so how much is it?

Steve Mc

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I contacted SLEC via their web-site 'Contact Us' option and got a prompt reply. I then ordered over the phone as I didn't see any other obvious way. I think they may be putting it on the web site soon from what was said over the phone.

The CNC parts are £44.38 and the wood parts £19.79. Being even lazier than Peter Miller claims to be I ordered both sets. I'm not sure what's included but SLEC is very trustworthy outfit in my experience so I don't expect to be disappointed.

On a good note for them, they seem to be thriving in the current extended building season. I suppose it's an ill wind ... and all that.

Geoff

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Posted by Michael Guinness on 23/08/2020 04:50:22:

Hi Geoff, and anyone else planning to build L'il Cub, I have had similar experience on my maiden flight with regard to the inability to turn right. My first flight nearly ended in disaster. My c of g is as per the plan. My ultimate solution was to increase the aileron throws and mix in about 30% rudder. I would also strongly suggest both down and right thrust especially with low kv motors coupled to larger props. As per my previous post, the offset hinged flaps are really powerful and enable slow, fully controllable flypasts and walking speed landings even though my L'il Cub weighs 2.2kgs. The very soft and light 5inch Tundra II wheels also prevent those bouncy landings. I am now enjoying my model with the small but effective changes in place.

That's worth noting. I usually put some right thrust in even when the design doesn't call for it (about 2 deg). My DB 58" Tiger Moth, which I acquired part-built, refuses to stall turn right because I have to use most of the rudder movement on the vertical (though Ian Redshaw managed it, but he doesn't count!). I made sure my 58" DB Cirrus/Gypsy Moth had some and it flies as perfectly as my modest skills allow.

What motor/prop are you using? I think I'll opt for Peter's choice of a 4max PO 3535 870kv rather than do my own thing as I usually do. The reason I'm building this is for it's low speed, low level capabilities so I don't want to prejudice that.

Geoff

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  • 3 months later...

Good day fellow Líl Cub builders and flyers.

As posted earlier, I have made a few changes to my Lil Cub which have improved the handling and controllability but the model still has peculiar behavior traits. Turns are inconsistent and the model pitches irregularly. A few club members have flown the model and suggested changes but none have had a positive effect. I have avoided flying it as I am just not enjoying the experience. In desperation, a mate offered me a 3 axis gyro to try out. I have had no experience with gyros so didn't expect a positive outcome. Tested the model today, all three axis gains turned to max. OMG!! What a difference! Is this the same model? On take off she tracked straight down the r/w, normally I am hard on the rudder to keep straight. In the circuit she was rock steady, like flying on rails. The approach for landing was textbook, no wing rocking and the landing roll controllable, no tendency to ground loop. I am totally amazed and impressed by the effect of a very inexpensive gyro. I have just met my new best friend, will be using these gyros for future models.

So, worth trying? Works for me, I can highly recommend a gyro if you feel your Lil Cub is not performing as you feel it should.

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Hi Peter,

Thanks for your reply. I do feel that the changes I made to your build. ie more powerful motor, larger prop, bigger ESC, 3d printed engine and slats, all adding additional weight, could well have attributed to my handling problems. I think the positioning of the LE slats, quite critical, may also have lead to some handling irregularities. All that said, I am now really happy with my Lil Cub.

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That's a bit smaller than Peter's design, Claes. Peter's (and the one most here would be building - including me) is just slightly under 1.4 metres. At least my wing is; I've just measured it.

I've made the slot parts but they won't be fitted until the wing is covered. I see you've left them off your larger one, too in the video. Have you tried them yet? I think I may leave mine off until I've test flown the model.

Your big one flies very well, I'm sure the 800mm wing span one will, too. It certainly looks the part.

Geoff

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Thats' what I'm hoping for, Peter. But as the slot arrangement is added after the wing is complete and covered there's no reason not to try before it's fitted even if only to see what difference it makes.

Yes, it's mild wet and windy here in the UK, Claes, at least where I live. I'd prefer cold, dry and still but we rarely get that

Geoff

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  • 1 year later...

I know its a while since Little cub was featured .I am some what a novice but wanted a challenge so I took on the build of little Cub ( with flaps), I have had some problems with the flaps etc. I put everything aside and have gone back to it. I fell down on the whole issue of flaps,

I wont bore you with my efforts but I badly need some advice.It seems the simplest solution is to fit some Flap hinges directly between flap and wing ( Basic extended arm  hinge type ?), as shown by someone who printed out some, (Page 2/3 I believe of this post.)  I have tried to order some on line but there appears to be more that one type. Can some one recommend a suitable hinge (preferable with supplier) as the choice is confusing for a novice builder like me. There are a few out there but the phrase ' Door/panel/hatch hinges, or off set occur , I have not seen the phrase Flap hinges.!!!!!

I thank you in advance for possible replies.

Bas

Edited by Basil
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Hi Basil. Just spotted this, it seems that the notification of a new post on the thread was not carried on when they revamped the forum (Tut tut!!)

I hate to say that but I can't remember what hinges I used. I will have a search through my old computer and see if I can find the text. I keep the plans but not the text.  However  you could use the old "Clothes horse" hinge.  I will find the drawings for the and give you the description very shortly.

 

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  • 7 months later...

I finished the Lil Cub end of last year, just a few minor things left to sort. I went on to some other more day to day building and flying. Well I have returned set on getting the model in the air. I have mislaid the article. Can any body tell me the requirements for  control surface movements  to get me started. Thanks in advance.

Bas

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