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[tonyH]

This may be a bit fanciful but could be fun in the attempt!

Has anyone tried anything like a 1:36 Ajax/Achilles with a flying Walrus?????????

I'm trying to decide on the next project and am saddled with a 15yr old son who came to the Mayhem Weekend and caught the bug in a big (I mean BIG) way.

I realise that we're talking about 15ft of ship but, split in half, that's not a problem and the structure/fittings are fairly straightforward but has anyone any experience on small, electric powered, biplanes (15" or so span)?

It seems that brushless motors, cells and the rest of the electronics are now so lightweight that it could be viable at a reasonable cost so...

Any Thoughts?

Tony

[Bunkerbarge]

Have a look at this site:

http://www.flyingstyrokit.cz/web.htm

It's not exactly what you are after but it does show you what can be done.  Have a look particularly at the Flying Boot model and a couple of other bi-planes.

They are all foam electic and just have a look at some of the scale model videos to see how they perform.

[tonyH]

Just to explain for the benefit of the questioning smiley which magically appeared post post, a 1/36th Leander class cruiser with a catapult launched Walrus. The ship would be 14'6" long and the Walrus (See other thread) would have a wingspan of about 15 inches.

Bearing in mind that a complete radio kit for lightweight electric planes can come in at under 15grams (Rx, speed controller and 2 servos), the motor at about 30 grams and the LiPo cells at about 50 grams each, the total weight could be well under 300 grams but since I've absolutely no experience of flying machines I'm after any advice.

Thanks

Tony

[justboatonic]

You've a couple of problems here with the plane. At such a small wingspan, the plane will probably be very twitchy (sensitive to commands). You'd also have to fit micro servos x 4 (throttle, rudder, elevator and probably ailerons) receiver and battery pack for receiver and motor. The wing loading would be very high, I'd suggest.

Next, you'd have to catapult this small twitchy plane off the ship. If you've ever hand lauched a small powered plane, you'll know the hand launch has to be a smooth, progressive 'let go from the hand' type launch and not a chuck like throwing a paper plane. If you do that (and a catapult launcher almost certainly will!) I can garantee the flight will last about 3 seconds if that! To cap it all off, you have to do this from water!

I really dont think it can be done.

[sinjon]

As justboatonic says, rather unlikely, the challenge would to do the plane bit first, before committing yourself to a 14' monster.

Colin

[tonyH]

Thanks for the input. I know that it may not be possible but I think that it will be worth trying.

I've been asking around in the electric flight brigade and as far as the wing loading is concerned, it doesn't seem to be as bad as first thought. I've done some general comparisons with commercially available planes and the weight falls into the same parameters. OK their R&D departments are better set up but conversely, the safety factors they have to build in are greater. Controlwise, I'd stick with 2 servos and a throttle. The rudder would only complicate matters and would only really be needed on the water, manouvering back to the ship.

I'd assumed that the catapult effect has to be progressive but this can be done with either a winch arrangement pulling the launching cradle via a pulley or, like a compound archery bow, using a cam on the 'elastic band'.

I think that it's one of those projects where the only way to find out is to try it. I'll build the plane and catapult setup and just see what happens.That said, the one thing that does scare me is the point that you made regarding the handling. If it does fly and the twitchiness of the plane meets the twitchiness of my driving - well - something is going to get wet!

Any more thoughts would be much appreciated.

Tony

[tigertiger]

It would not be to scale as such, for the Walrus
but have you thought about modifying a small park flyer.

some of them have only a 9" wingspan, so the ship could also be smaller.

[tonyH]

Hi Tiger,

Thats the sort of thing.

The only problem with a lot of those is that many are made with twin motors and the steering is done by differentiating the power to each motor. Would be great for a Catalina flying boat!

Many of them seem to come in from China, so any ideas on web sites etc.

Thanks

Tony

[Guy Bagley]

my son has one of these RTR polystyrene park flyer things... wingspan is sadly too big at 24 inch - steering is by the TWIN motors, but the overall quality of the kits is awesome, its very lightweight and the mimh battery gives about 8 mins of flight if your are an  efficient pilot !!!- its a great little 'toy' with half decent R/C model charachteristics.......
 the receiver , and controls for the motors are a  tiny printed circuit board.....

i am sure this type of park flyer my be a good starting point, i know there are some single engined type ' pusher' mini park flyers, the prop  is designed to push the model but these could be butchered to run as a puller prop model, there are also the sub miniture indoor flying types too,  take al ook and see if there is a wingspan to suit what you plan to do...

hobby zone is a name i remeber, i also think howes models do alot of their RTR stuf. also last year at the souther model airshow ( hop farm) there was a stand selling a whole load of 'small' park flyer models for not alot of money..... might be worth a visit ????

[tonyH]

Thanks Guy,

I'm sure that it's worth a go.

The pusher type is exactly right anyway for the Walrus. The only thing is that the prop is likely to be oversize but its virtually invisible when spinning anyway.

Experiments start next weekend.

Tony