Airspeed Courier

[Peter Miller]

I like your Pix-e Tim.

 

I could never get the original to fly back in the early 50s. Probably my lack of experience but it just would not fly for me. I can't rememebr seeing one fly but they must have done.

[Tim Hooper]

Thanks Peter!

 

I have to say that the little Pix - E is a lovely model to fly, although it seems to do even better if I leave the sticks alone!

 

tim

[Pat (rActive) Harbord]

Tim, this looks fabulous. Yes please to a plan (free or otherwise) hint hint david

[Tim Hooper]

Posted by rActive on 19/11/2010 15:51:08:
Tim, this looks fabulous. Yes please to a plan (free or otherwise) hint hint david

 I'll do my best - promise!

 

Having deliberated for weeks, I spent a bit of time on Saturday cobbling a steerable tailwheel together.  A piano wire leg pases through a plastic tube (itself glued within a hardwood block), and has a bearing disc of brass soldered below, and brass arm soldered to the top.

I did contemplate (in turn) a fixed wheel, a castoring wheel, and a tail skid, but thought that this would allow for any eventuality!

 

Now the other end of pushrod is connected to the rudder servo,  but not wanting to transmit any undue loads to the servo's tiny gears, I've made up a sort of shock absorber with a couple of short lengths of silicon cable insulation.  I've used simialr items before that use steel springs, so we'll see if this works, eh?

 

 

Other than that, I've spent a few minutes fitting the dummy engine cylinder in place withing the cowl ring.  They'll look better when when they're painted....

So now it's time to start filling and sanding!

 

tim

[Peter Miller]

Hi Tim

 

I have a future project for you.

There are other pictures.

 

I designed a CO2 powered version many years ago at 22" span and it flew FF like a dream. SAMs models do my plan of that model.

 

I toyed with the idea of a big one but for the power that I would want to use it would be very big, far wider than my my board.

 

There is a Russian Website that google can translate after a strange fashion.

 

[Tim Hooper]

What a bizarre looking creature!

 

(No, not you Pete - I meant the aeroplane.......)

 

It's a sort of motor-glider I suppose.  No shortage of wing area either!

 

tim

[Peter Miller]

I thought that you would like it.

 

Yes, it started out as a glider which was aerobatic. Then in 58 they fitted a little flat twin engine.

 

As I said, my CO2 version flew like a dream.

 

Yes, I probably look bizarre too but not quite as much as that.

[Tim Hooper]

Have to admit, Peter, it does look tempting......

 

Anyway, I'm strictly a one-at-a-time sort of bloke, so I'm now festooned with silver Solarfilm......

(Mind you, I've just ordered 10 metres of Solartex for the next project.......)

 

tim

[Tim Hooper]

Now, covering isn't my favourite part of a build, so I tend to have little projects on the go to distract me form time to time.

 

So with the wing covered, I figured it was time to paint the canopy framing with silver enamel, and then start to actually glaze the cockpit.  Although there are no compound curves involved, it is quite complex so I'm doing it in small section.

 

tim

 

 

[Tim Hooper]

It's been a little hectic here over the last few days, but I have actually managed to finish the last of the glazing.

 

The four overhead panels were best done one at a time.

Then the frame was disguised with strips of silver Solartrim.

Anyway, here're a few more pics of the full-sized Courier, in order to offer a few more colour schems.  The RAF camoflage looks pretty obvious (including a much deeper cowl), but I'm unable to obtain any details of the actual colours used in the other schemes.  Any guesses?

 

 

 

Edited By Tim Hooper on 01/12/2010 17:19:50

[Tim Hooper]

See?  I told you I'd been busy, didn't I?

 

tim

 

 

[Peter Miller]

Very neat indeed.

 

You wil find a picture of an all silver courier here

http://www.airliners.net/aviation-photos/

 

The best site that I know for aircraft pictures.

[Danny Fenton]

Really looks great Tim. I look forward to the assembled shot

 

Cheers

Danny

[Tim Hooper]

Thanks Peter!

 

Dan, I'm going to get the model in the air, just to see if it flies, before I start on any graphics or detailing.

 

The tail surfaces are installed and hooked up to their servos, as are the ailerons.  The motor is installed and tested (Turnigy 3542 1250Kv).  The 9x6 prop is balanced, so now I'm just working out where to place the battery to achive the correct CG.

 

Nervous? Me?  Naaaah.......

tim

[Danny Fenton]

This will fly beautifully Tim, it looks right  I know its not the sort of question you ask of a lady, but how heavy is she?

 

Cheers

Danny

[Peter Miller]

Weight is not the question to ask, it is meaningless on its own.

 

What is the wing loading?

[Tim Hooper]

OK, out with the calculators........

 

Weight currently stands at  2lb 10oz (including 3S cell pack), so it really shouldn't be much more than, say, 44oz when completed.

 

Wing area is pretty close to 415"², so that equates to a loading of around 15 oz/ft.

 

Unless my maths are wrong, of course.......

 

tim

[Peter Miller]

That is very good. Should be really nice.

 

My Fournier will have a wing loading of just over 17 oz per sq. ft.

[r6dan]

That is looking really good,the glazing looks to be a bit of a pain though!

[Tim Hooper]

Peter,

 

Just for you, I've blown the dust off my Wattmeter this evening and taken a reading.  At full throttle (on a fresh 3S 2700Mah battery)  the Turnigy 3542 1250Kv motor (on hard timing), turning an APC 9x6 prop is pulling 39amps, and showing a total of 460 watts.

 

This equates to a power loading of 167watts/lb.  I knew you'd be fascinated......

Dan,

You're right about the glazing - it's best done a bit at a time, in amongst the rest of the build.

Right, it's ready for its maiden!  Trouble is the weathewr looks appalling for the next few days, so I might as well plod on with the graphics....

tim

[Tim Mackey]

Looks great as usual Tim

[Peter Miller]

Tim.

 

Now you are getting too technical. However, based on your figures it should be great on a .15 Possibly even a touch over powered for scale.

 

What rpm was the motor doing on the 9X6?

[Tim Hooper]

Posted by Peter Miller on 06/12/2010 08:41:14:

Tim.

 

Now you are getting too technical. However, based on your figures it should be great on a .15 Possibly even a touch over powered for scale.

 

What rpm was the motor doing on the 9X6?

 

 Peter,

 

I think that 460 watts would be equivalent to a .30 glo, or thereabouts.  Obviously, there'll be no shortage of power!

 

FWIW, the power train I'm using is a 'known' set-up, which I'm using in two other models - my 50" Seagull PC-9, and Nettys 50" Seagull Spacewalker.  Both are 'comfortably' powered, and capable of big, smooth aerobatics.

 

All of which means that I'd reckon that the Courier would be viable on a .15 or .20 sized glo.

 

Bit of a confession here in that I've never possessed a tachometer!  However, if we assume that the theoretical figures are correct, then our 460 watts divided by the 39A current draw means that the batteries are supplying about 11.8 volts under load.

 

11.8 volts multiplied by the stated Kv value of 1250 yields a RPM figure of 14,737rpm.

 

 

Naaaah......I don't believe it either! 

tim (looking for a laughing derisively smiley)

[Peter Miller]

My .15 powered semi-scale racers are roughly the same size with slighlty higher wing loading. They go like stink and are very aerobatic. The engines are turning 8X6 props. Not checked the rpm.

 

My 32s run on 10X6 props at around 12,000. a .25 would be on a 9X6 and somehwere around the same rpm.

 

My "Little Bandit" has 451 sq. in and a wing loading of 19 ounces per sq. ft. It does the book on a  West.25 on a 9X6 and 10% nitro.

[MarkyMarc]

Posted by Peter Miller on 05/12/2010 08:22:51:

Weight is not the question to ask, it is meaningless on its own.

 

What is the wing loading?

 

About half of one of your designs, Peter...

 

Just kidding