nose weight?

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Steve L - 31 Oct 2004 00:23 GMT

Hi
Just finishing of assembling an ARTF Super Sports 40 and checking the CoG by
hanging Allen keys from the firewall. I can get a balance with 160g of
weight (empty tank) but this seems rather a lot. I am using a OS LA.40, The
plane will take a .50 which I suppose would be heavier. The flying weight is
supposed to be 2500g, the tank is 320cc (300g? when full) with noseweight
(160g) and the actual plane weight (2280g) totals 2740g which is 240g
overweight. The battery is as far forward as possible. Is 160g of noseweight
unusual? should I worry about it being 240g overweight? - (I wish I was only
240g overweight but that's another story ;-})

Thanks

Steve

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SteveS - 31 Oct 2004 10:11 GMT

> Hi
> Just finishing of assembling an ARTF Super Sports 40 and checking the CoG
[quoted text clipped - 10 lines]
>
> Steve

Is this the World Models one? If so, then my experience was that the quoted
C of G was much too conservative. I started off with something like half a
pound of lead in the nose until I saw the error of my ways. It won't be a
stellar performer with a 40LA. I have a 46 LA and it's adequate. Watch out
for the aileron hinges being stiff, and if you don't glue the tailplane on
regularly check the screws.

Also, I'd advise changing the nosewheel leg for a stronger one. If you keep
it steerable, file a flat on the leg prior to attaching the tiller arm.

HTH,

Steve S

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Steve L - 31 Oct 2004 13:04 GMT

Thanks for the response Its is very helpful..
Yes, it is the World Models SS40. What noseweight did you end up with? In
view of your experience, I'm thinking of trying 6oz. The nosewheel came with
a 'flat' already filed into it for the tiller arm. It seems to be man enough
for the job and I had to drill out the holes in the engine mount to get it
to fit, perhaps World Models have now changed it?. I will keep a close eye
on it. All the control surface hinges seem a bit stiff so I've had a go at
loosening them up by 'working' them. Its still not great but I think it will
be OK. The LA .40 and the electronics have been salvaged from a Wot4
following an unscheduled 'landing'. If buying new I would have opted for
something larger. I agree about the tail screws. All the screws in the kit
are a bit naff and the heads don't seem to be either Pozi or Philips.
If the mist clears up today and the wind stays low I'll give it a go this
afternoon.
Cheers
Steve

>> Hi
>> Just finishing of assembling an ARTF Super Sports 40 and checking the CoG
[quoted text clipped - 25 lines]
>
> Steve S

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Dr1Driver - 31 Oct 2004 15:46 GMT

>Just finishing of assembling an ARTF Super Sports 40 and checking the CoG by
>hanging Allen keys from the firewall.

Your choice of engine for that plane is a little small. The .40 LA is a
lightweight, low-power engine. For that plane, I would recommend at least a
.46 FX-type. You might even consider a .50 size or a .60 four stroke.

Your plane is overweight by only 8 ounces. While this is regrettable (lighter
planes fly better), it's not excessive. Sometimes, manufacturers weight
estimates are optimistic and ARFs usually build heavy.

Since the battery is as far forward as possible, try to move the engine forward
on the mounts, if you can. Barring that, add the noseweight securely and
double-check the CG. It should be between 25% and 33% of the wing chord, back
from the leading edge. Sometimes the CG stated on the plans is not correct.

Good luck with it and keep us posted.

Dr.1 Driver
"There's a Hun in the sun!"

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Paul McIntosh - 31 Oct 2004 17:20 GMT

A Higley Heavy Hub will add about 2 oz to the very front of the nose and
also help with low idle reliability.

Do you have the battery under the fuel tank? Many ARFs have just enough
room under there.

--
Paul McIntosh
http://www.rc-bearings.com

> Hi
> Just finishing of assembling an ARTF Super Sports 40 and checking the CoG by
[quoted text clipped - 10 lines]
>
> Steve

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Model Forum / Radio Controlled / Air Models / October 2004

nose weight?