HK Wicked Wing/Windrider Bee2

[Ian Jones]

I've almost completed my Hobby King Wicked Wing (which appears to be a Windrider Bee2) all that's left is to balance it. The recommended battery pack is 4xAAA but I've fitted 4xAA which is quite a lot heavier and goes in the nose. For a variety of reasons I've used metal geared mini servos, so under the tape it looks like this (only tidied up ):

Mini servos can be fitted further outboard on the wing and that position is slightly more reward than the standard position I have used. So I expected the balance to turn out something like right or a little nose heavy.

The stated CG is 200-220 mm from the tip of the nose. As it's difficult to balance on one central spot I've set a cardboard roll along the balance line:

So I'm rather surprised to find that to get it to just about balance I have to put 60 grammes on the tip of the nose:

Although this takes the wing to it's max weight of 650 grammes it still seems excessive to me.

Is there something wrong? Anyone spot my deliberate mistake?

Thanks, Ian

Edited By Ian Jones on 07/03/2014 14:58:54

[Bandit]

Must be a mistake, mine has a very similar battery but standard servos as I was advised to make it tough for the slope.

Checking my CG now balances at roughly 200mm from the front.

Have you got some standard servos maybe your servos are light.

[Ian Jones]

Thanks Bandit, look like it's the light weight servos then, just 13.5 grammes each and added to that (or taken away ), the Rx is only 6.5 grammes. Since the instructions show the fitting of a 35 Mhz aerial it would seem a heavier Rx was expected too.

The servos are metal geared and stall at 18Kg/cm and I'm sure they will be fine. Better had be, this poor thing could end up facing the likes of Tim Mackey and Iawnski - they shoot first and ask questions later , that's why I've fully taped it.

I've used the spare space in the servo bays for a power harness and charging socket.

[Bandit]

Gone for the expensive stuff

Mine runs on two cheap old 3003's with an orange receiver and a NiCad 4 cell. No switch just lift the taped hatch and plug the receiver in.

It flys ridiculously well and I highly recommend owning one as they are tough as old boots.

I stuck with the Velcro for the wingtips but glue the Velcro on to the wingtip and wing or it will just peel-off.

Having flown mine for many hours it has become that craft you always take, the back-up, the one when fun is needed, the wood stove that always works, the one to use to try a new slope.

If you have some old 3003's hanging about I'd go with those as the control surfaces come out the top so very well protected and metal gear stuff could be saved for something else. It could be a little heavier as if the wind really gets up they struggle to penetrate but an average day soaring they are an absolute pleasure!

[Ian Jones]

Well that's all good news Bandit because my plan was to have something to fly when the lift isn't really up to holding my SAS Fusion up (it's heavily taped and ballasted).

I have some loose ideas about making it an all rounder though. The basic idea is simple enough, just a detachable ballast fuselage which will help with launching if it's blowing a bit but that's also the problem... being able to attach the fus at the slope securely without using wing bands which must surely damage the foam in time.

Have you stuck with the suggested control surface movements?

Maiden tomorrow with any luck.

[Bandit]

I have to confess the hooligan within pushed the throws a bit

Don't think you will need ballast for 90% of cases.

It is such a tough little wing, I cannot emphasise this enough when done with the weave tape.

Launching was a little tricky. I have taken to a discus type launch which is a little hectic to start with but you can just push them off from the rear supporting the front of the wing.

Nice thing about wing flying is you keep one hand warm

Good luck with the maiden and I expect to see a row of smily faces when you report back

[Ian Jones]

Well I couldn't have picked a better day to maiden it. Warm and sunny which was just as well as I'd forgotten my nice warm jacket. I and the wing survived:

The full 60 grammes that CG testing indicated was needed is taped under the nose to make a handy grip when launching. On the first 2 attempts it failed to get away but when I trimmed the reflex down a bit off she went, followed by a load more down trim! It became clear that the balance was just right for the decaying lift/wind conditions at the time which is good because that is what I wanted it for. I hit a thermal at one point and it climbed rapidly soon becoming uncomfortably high and I decided to roll out of it. It was indeed a good smooth flyer and despite lots a of my dodgy launches went home unharmed.

Oh and I got a sun tan thrown in.

Thanks for your help Bandit.

Ian

Edited By Ian Jones on 10/03/2014 14:04:42

[Martyn K]

That looks nice Ian

Martyn

[Bandit]

Excellent

[Ian Jones]

Posted by Martyn K on 10/03/2014 14:05:12:

That looks nice Ian

 

Martyn

I'm glad you like it Martyn, you may be getting very friendly with it before long .

Puzzled? You won't be when the modifications are done but for now my lips are

 

Posted by Bandit on 10/03/2014 14:22:34:

Excellent

Thanks Bandit, now that's got it flying there's some fun to come I'm sure. Oh and thanks for warning me about the velcro. I've nailed it on now so it should be okay .

Edited By Ian Jones on 10/03/2014 22:45:44

[Tom Satinet]

couple of points

1) you can remove strapping tape even if you have used 3m 77 spray. If you heat it with your covering iron it will come off quite easily. I didn't believe it till i took at the tape off an m60 fuselage.

2) conventional wisdom on rcgroups is that the CG of bees is 8.25 to 8.5 inches, which is a lot further back than the wind rider instructions. not surprisingly they also use bigger tip fins.

[Ian Jones]

Thanks Tom,

Useful info.

[..]

Hi Ian, I have the XL version and despite using metal gear servos & a larger batterie pack I still had to put a fair amount of lead in the nose. They fly well , you won't be disappointed.

[Ian Jones]

Well the maiden was fine... there'll be more fun when I've done some "upgrades" I have in mind. There's 60 grammes of dead weight on the nose I can play with, hmm.

Hope to make a start next week.

[Steve Houghton 1]

I have a Bee, fitted with 4 AA pack and standard servo's, and I had to add about 30gm of tail weight, and it could probably take a fraction more too. I've had about 2 good years flying out of it but its due for a recover soon I think.

Steve

A470Soaring.blogspot.com

[Ian Jones]

Hi Steve, good to hear from you, yep it's those lightweight servos that made mine too light on the nose, yeah you are right it flies well.

A replacement for my long lost....

[Tom Satinet]

Ian

 

How are you getting on the with CG? As I said they are insistent on rcg that the cg is 8.25 inches +. By that they mean 8.25 inches from the nose straight back. IIRC windrider gives the CG as a distance along the leading edge.

 

I have the beevo and I have a AAA pack in it and it's still slightly nose heavy of 8.25 inches. I think the planform is the same - but with a different aerofoil. Obviously you will need lower rates on the elevator for a more reward CG.

 

I am just wondering if your need for nose weight is due to the forward CG and maybe you will get more performance with it further back.

I'm waiting on some correx from ebay to make bigger fins as they look small to me and the "predator bee" instructions also go for larger fins.

 

Tom

Edited By Tom Satinet on 02/04/2014 14:51:58

[Steve Houghton 1]

I extended the fin area on my beevo, by about an inch I think, as per the Predators recommendations. I think on my pic above you can see the fins protrude beyond the elevons.

[Ian Jones]

Tom,

The Wicked wing instructions state 200-220 mm (7.8" to 8.6"  ) from the nose tip backwards. Once I'd got the 60 grammes on it was tail heavy at the 200mm point but nose heavy at the 220mm point so since that was some where in the middle I decided that would do for the maiden, having been reassured by the previous posts that it was somewhere near right. As I mentioned earlier it turned out that was just right for the conditions on the day. It turns out that although I used a heavier battery pack than recommended (which I thought would make it nose heavy) the lightweight servos more than compensated for that, hence the noseweight to balance it. Thanks for the help.

 

Steve,

Thanks again, I'll increase the fin area as you & Tom suggest.

 

Justin,

Thanks, yes you are right it's a nice steady flyer. It will indeed be seeing a lot of action, combat action if certain people get their way... hmm thinking about the suggestion of increasing the fin area, I may put some little fins each side of the push rods and they will double up as a little bit of protection against Mackey's Marauders .

 

Thanks everyone, Ian

 

Edited By Ian Jones on 02/04/2014 17:05:57

Edited By Ian Jones on 02/04/2014 17:06:28

[Tom Satinet]

Hi Ian

that makes sense then. I used standard servos which weigh 40g each. The wicked wing instructions for the CG are inline with the rcg and "predator" recommendations.

I think the weight distribution also depends on if you do stuff like thinned goop and obviously the tape you put on.

T