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THIS IS THE TEST SITE OF EUROBRICKS! ×
THIS IS THE TEST SITE OF EUROBRICKS!

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Posted (edited)

So here is what it should look like when done....

saab.jpg

And here is the "central" engine with a three speed gearbox.

P1000402_zpsede0aab0.jpg

I will not bother on listing functions at this minute,but if you know me there will be some. :tongue:

Edited by Alasdair Ryan
Posted (edited)

New pictures....

IMAG0019_zpsa9dd48c1.jpgIMAG0020_zps5edd0d2a.jpg

I bought a train motor from lego shop Glasgow to power my plane,it verily spins. :sweet:

The other out put will be for a flashing light sequencer.

There is also a axillary output to be added to 2 and 3 gears.... :devil:

Edited by Alasdair Ryan
Posted

Looks good so far! About what Gee said about wishing he had a Lego shop in Worcester, I live in Vancouver Canada and am lucky to have two Lego stores within 50 minutes train ride. Unfortunately neither store really caters to Technic. Alasdair how is the Technic selection at your local store? For instance, is there any Technic on the PaB wall?

Posted

HI,

I do Moc essentially airplanes helicopters...and such things.

The first thing that comes in my mind actually looking at your work is that you do not begin with the appropriate thing.

You should have a general view of your concept, a good scale for your model and most important of all a prototype of the cab frame and wings.

In such a Moc, the essential difficulty will result with the structure that must goal with design (rouded shapes) and resistance (structural design)

Once that's done, you will be in good position to integrate all equipement and motors.

Good work!

Posted

Looks good so far! About what Gee said about wishing he had a Lego shop in Worcester, I live in Vancouver Canada and am lucky to have two Lego stores within 50 minutes train ride. Unfortunately neither store really caters to Technic. Alasdair how is the Technic selection at your local store? For instance, is there any Technic on the PaB wall?

They only have the turntables on PaB,but have the new motors,new sets and mindstorms etc.

HI,

I do Moc essentially airplanes helicopters...and such things.

The first thing that comes in my mind actually looking at your work is that you do not begin with the appropriate thing.

You should have a general view of your concept, a good scale for your model and most important of all a prototype of the cab frame and wings.

In such a Moc, the essential difficulty will result with the structure that must goal with design (rouded shapes) and resistance (structural design)

Once that's done, you will be in good position to integrate all equipement and motors.

Good work!

Well now you will learn another way ,I always start with the gearbox in any build of mine I find the gearboxes are the hardest thing to build.

Once I know wear both outputs will be then I will build the main frame.

Nice to see you building a plane Ryan! Can't wait to see all those functions :wink:

Thanks jim. :thumbup:

Posted

Alasdair

I just did a google for you. Flaps are inboard of he ailerons (as you would expect as you want the maximum turning effort from the ailerons)

this image should help you

http://www.mobygames.com/game/windows/aircraft-collectors-edition/screenshots/gameShotId,547776/

as it shows the flaps in the down position

in this one you can see a number of supports underneath that have the 'arms' to lower the flaps

http://airlinersgallery.smugmug.com/Airlines-UnitedStates-3/Airlines-United-States3-QZ/Silver-Airways/i-89LSTL3

the critical thing is to end up with a visible slot between the flap and the wing when the flap is fully deployed

Hope that helps ?

Posted

Thank you very much for the pictures,I was able to find a image that shows the flaps down.This makes the plane gain lift.

But what I am unsure is how does it slow down/loss lift?

In other planes the end of the engine is not covering the flaps so you can have the flap move up and down.

plane_diag.gif

Posted

These are ailerons, they are used to bank.

Airliners have interceptors for slowing down/losing lift. Other aircrafts just cut on throttle or lower propeller pitch for slowing down or reduce angle of attack to lower lift (usually both)

Posted

Ok basic flight theory

'lift' is created by making air flow faster over the top surface of an object compared to the flow of the air underneath it ... this creates lower pressure on the top surface and so 'lift'

What a flap does is this ... it increase the 'curvature'(front to back) of a wing and so increases lift ... and with an increase in lift you can fly at a slower speed ... as lift is related to airspeed

the flaps on the Saab are 'slotted' flaps ... this means some air will 'leak' through the hole from under the wing to on top of the wing ... this means the air will stay attached to the wing longer at large aircraft pitch angles (nose up) and so it will also stall later

Does that help ?

P.s. I have an aeronautical degree

in terms of slowing down when its on the ground after landing

this plane is likely to use number of methods

1. blade angle / feathering where the prop no longer provides thrust and in some cases rearward thrust to produce an effect like a thrust reverser on a jet engine

2. brakes on the wheels

3. flaps ... the flaps will be fully deloyed once the plane touches down ... creating lots of drag

remember a prop aircraft lands at a much lower speed than a jet and so needs a lot less effort to slow

Posted (edited)

Actually the saab 340 is a turbo prop in the middle does this matter when slowing down?

Most turbo-props have the ability to change blade pitch, which helps when slowing down.

I've attached a picture with the ailerons and flaps labeled.

-The ailerons are towards the tips of the wings and control the roll of the plane. They move up and down.

-There are also trim tabs on each aileron, and they allow the pilots to make fine adjustments that control the level flight of the plane. They move up and down. Not really necessary on a LEGO model, unless you want to add that extra little detail.

-The flaps on the Saab340 appear to be a single flap on each wing that runs beneath the engine exhaust. The flaps provide additional lift at low speeds. The Saab340 uses single-slotted flaps with offset hinges. They move down. They don't move upwards (unless being retracted of course).

The Saab340 does not have spoilers.

Hope that helps! Looks like an awesome project!

Here is a link to some info that might help:

http://www.saabgroup... ever built.pdf

post-10485-0-72781800-1389978139_thumb.jpg

Edited by dhc6twinotter
Posted

Hey,

So, flaps are used to increased lift but also to slow down because the increased the drag. They are fully extended during approach to fly safer at the approach speed.

As said above you can use the pitch of the propeller to reduce the speed. Setting a fine pitch you will increase the drag and slow down.

As you can see fine pitch (a good aerodynamical brake!) VS coarse pitch

Then on the ground, again as said before, depending of the engine you can reverse the pitch of the propeller to slow down. It's not used in flight.

If you want to make a short field landing and the airplane is not equipped with spoilers (like the saab) or reverse thrust, you can retract the flaps after touchdown to reduce the lift, increase the grip of the tires and increase the efficiency of the brakes.

Posted

Pro builder coming through.... :laugh:

Here is the new three speed gearbox with another gearbox controlling each side.

I should now pick up speed,as it should be plain sailing all the way to the end. :look:

Sorry about the picture quality.

IMAG0029_zps43c6c8dd.jpg

IMAG0031_zpse2a37c66.jpg

Posted

Never ceases to amaze me how people can come up with these things. I struggle just getting direct drive to an axle!

Good stuff, lookin' forward to more progress!

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