Ayrton S

Hi all!

I've looked through the first 14 pages [X(] of threads on this forum but cant find any reference to the GWS BN2J-EDF (twin ducted fan version of GWS's Britten-Norman Islander). Only lots of references to the GWS A10...

As I've just bought a BN2J-EDF in a store sale for £25 ($40??) I'd love to hear from anyone who has experience of the type. It looks a lovely little model in the promo pics and vids.

Yours Hopefully

Ayrton S

Larry Dudeck

My Feedback: (1)

I use the prop version as my winter beater airplane. With its flat fuse bottom, no LG and high wing, landing in snow is easy. I fly mine on a 2Sx2150 LiPo, longest flight has been something like 15 minutes.

The BN Islander is one of those planes you can learn all there is to know in a very short while. Docile handling in calm air, bouncy when windy. Very easy to launch and fly on elevator and aileron only.

The BN is truely a "trainer"

travelmaven

My Feedback: (1)

I flew both the prop and fan versions of this plane. If possible go with the props (or modify). The duected fans just don't have the power. I went brushless on both versions. Nice looking and easy to fly airplane.

Ayrton S

Hey guys!

Those are both helpful posts - thx!

As I said, I got the kit in a sale. I think I'm stuck with the ducted fan version unless I do a bodge conversion to prop. Also 2 Fegaio motors and TWO (count 'em) brushless speedos for the fans would quadruple the price of the project []. I wonder if GWS will sell spare motors/props/mounts direct??

I was thinking of lightening it anyway, carbon pushrods, leave of the u/c etc. and of course use LiPos - I've got 380 2s1p's that I'll try first - might be a bit weedy for 2 d/fs. I may leave off the rudder servo too - any thoughts?

Thanx again

Ayrton

Larry Dudeck

My Feedback: (1)

I had a GWS A10 with the EDF55/300H fan/motor combo. Absolutely needed the 3S to make it go. The fans drew just about 15 amps, a GWS 15 amp ESC was fine. If the BN has these fans and motors, the 380 mahr packs just won't handle the current.

Regardless, dump the rudder, not needed if you plan on HL.

May as well keep the fans, big hassle to convert to props, invest in a better pack.

Ayrton S

That's really helpful, Larry, thx. The fans appear to be EDF-50A's - motors not specified but they look like the IPS geared motors (ungeared of course) complete with little heat-sinks attached. I've got a GWS 15A speedo and I'll definitely try bigger packs of LiPos - may even try a massive 3S pack (gulp) on your advice.

Thanks again

Ayrton

Larry Dudeck

My Feedback: (1)

Ayrton S

What is the blade count? The EDF55's have 6 blades.

Ayrton S

Larry -

My EDF50s have 3 blades! It's a bit difficult to work out which motor they have - I think its the CN12-R-XC, runs at about 7 amps each, 25500 revs no load.

Ayrton

Larry Dudeck

My Feedback: (1)

I have heard the EDF50 motors are weak, little buggers - easily fried if cell count is to high. What is the recommended cell count?

Ayrton S

Larry!

(are we allowed to say 'bugger' in this forum?? )

The recommended batteries are 6 cell NiCad or 6/7 cell NiMh (less pucnch than NiCads?) - between 400 and 700Mah. So I reckon I'm looking at 2S LiPos, what do u think?

Cheers

Ayrton

Larry Dudeck

My Feedback: (1)

Not sure why the difference between NiCd and NiMH, both 1.2v nominal.

Either way, 6 cells are nominal 7.2v while a 2S is nominal 7.4v. A 2S hot off the charger is closer to 8.4v which is 7 cells.

The 2S will be a better choice as it will be lighter. You may have to hog out some foam to move the LiPo pack forward but that's what potato peelers are for.

Ayrton S

LOL!! Tell me how to use a potato peeler to cut foam!!

Re: recheargeable cells, here goes: NiCads are generally acknowledged to have a better 'punch' than NiMhs at launch, due to a lower internal resistance and hence a higher amps draw in the initial stages of discharge, HENCE the lower cell-count recommendation for the Islander IMHO (same whether prop or fan driven BTW).

OK, but a 7-cell NiMh hot off the charger is way above 8.4 v - I think i've seen them up to 11v........

....this stuff is more complex than I like to think about.... LiPos are the way to go anyway, and 2 cells seems tops here - thx for the help -

I MAY try to beef up the airframe with v light fibreglass mat and water-based polyurethane varnish - anybody got any experience here??????

Cheers

Ayrton

shschon

My Feedback: (4)

I have the EDF BN2.

Using the stock EDF-50A it is a low voltage motor you MUST NOT use 3 cell LiPo or you are going to fry them quick.

Even 7 cell NimH you need to watch out and ease on the throttle.

Batteries very greatly in power, you need to have a power meter to see that exact voltage under load to be sure.

I reommend great planes 1500 mAH 2 cell LiPo battery which is a good compromise between power, weight and motor longevity.

If you want to use 3 cell LiPo you need to change motor and possiblly the impeller. There is EDF50BH brushed version that use high voltage motor and 5 blade impeller which you can use 3 cell LiPo.

For more power you upgrade to Feigao or Medusa brushless motors.

Ayrton S

Thanks Shschon!

That's very helpful feedback and tells me exactly which batt to go for.

Do you have any other tips re the kit? Is it underpowered as stock?

Cheers

Ayrton

Larry Dudeck

My Feedback: (1)

I've used 1/2 oz FG cloth with WBPU numerous times. The finish is not as hard as that acheived with epoxy but it is lighter. Also it is much easier to use, just brush on and let dry. No mixing, no fuss. And, for me at least, no allergic reaction.

"...LOL!! Tell me how to use a potato peeler to cut foam..."

Potato peelers have a sharp, pointy end which works very well for hogging away the foam in small pieces.

Ayrton S

Larry

At the moment I'm just looking at a tin of varnish from the hardware store clearly labelled 'Clear Satin Water-Based Polyurethane Varnish' with water washable brushes. Is this the stuff to go for? I've never seen anything written about this process.

Also 1/2 oz sounds about the lightest glassfibre cloth you can get - am I correct?

Thanks for your help with this project - it's taking shape, in my mind at least (the kit's still a 'loft queen' at the mo)

Cheers

Ayrton

PS must buy a pointy spud peeler while I'm in the hardware store!

Ayrton S

Gosh![X(]

Look what I found!! It really existed! Does this mean there is a full-size 4-turbofan C130 Herky out there somewhere?

Ayrton

PS happy birthday Herky, 52 years young!

new york flyer

Hey, nice pics of the Islander. I suggest you put a lipo on it. I modified mine and put in a 7volt 2cell lipo, im able to climb higher and glide longer. Just adjust the weight and balance, it will fly great. Its an excellent aircraft

Here is a pic of mine, i modified the landing gear for ruff terrain.

Ayrton S

Hey NYF

Nice plane! Thanks for taking the time to reply. I have a 1300 mah 2S1P lipo pack ready to try - but I notice you have the prop version rather than the fan. I may try to get 2 prop motor nacelles in case I need to convert - we'll see.

I'm attaching a couple more pics of the full-size - one looks exactly like yours apart from the u/c (aluminium?) and the other is a Trislander which you may not have seen. I've only seen one - weird bird!

Cheers

Ayrton

Larry Dudeck

My Feedback: (1)

"...'Clear Satin Water-Based Polyurethane Varnish..."

Sounds right to me, although I would try a drop at some unobtrusive spot on the fuse, just to check for compatability.

Another process I just tried and seems to work better than WBPU. I used interior latex wall paint. Put a coat of paint on, lay the FG cloth down onto the wet, painted surface, smooth out and let dry. Apply a second coat of the paint

1/2 oz is the lightest.