Fixing Roll

[Wolf_Rider]

basic law of motion... "For every action there is an equal and opposite reaction"





http://www.aerospaceweb.org/question...s/q0015a.shtml

might help/ might not

[bongodriver]

Me personally no, I studied enough of that on my ATPL theory, so I am fully up to speed on all these effects.

[Wolf_Rider]

sorry, I meant "might help" for readers in general not directly for you... my bad


(I'd take a heavier flywheel, than stock, in my daily ride any day... they're so good for storing all that kinetic energy, eh)

[bongodriver]

Originally Posted by Wolf_Rider

sorry, I meant "might help" for readers in general not directly for you... my bad

Ah! OK......my bad too for assuming, I figured we were saying the same thing anyway.

[StreetGang]

So after 3 pages, what was the technique to reduce roll ? I do at the moment just trim the rudder, but then your craft is crabbing across the sky, surely this isn't what actually happened, I couldn't imagine BoB pilots being happy with crabbing.

[madrebel]

the italians solved this by extending the left wing of the macchi aircraft by 8.5". left wing created more lift and counter acted the roll.

[jimbop]

I trim elevator first, then rudder to remove crabbing, then manually hold against the roll with the stick.

[_RAAF_Mini]

I know for a fact that the Spitfire did have trim tabs on the airlerons for trimming but they could not be adjusted in flight. When the pilots lands he made his own corrections using a block of steel and a malet.

Small excesses of metal on the airlerons surface could be bent up or down to counter act any trim issues the pilot was having on his next flight, the problem would then hopefully be solved for his next hop.

Here is a video where a Spitfire is shipped form Duxford to the USA and it shows when they are doing the flight testing after it is rebuilt the pilot trimming it. Go to 40 minutes in. He trims it just after he lands. Sorry for any adverts on this video, it's a TV Channels on demand service.

http://www.youtube.com/watch?v=24eu9cQJ0cY

Cheers
Mini

[b101uk]

Originally Posted by Wolf_Rider

its like this:

A helicopter had to have the tail rotor put on it for what reason?

that's right... to prevent the main rotor and the main body (housing the engine) from spinning in opposite direction.

double main rotor 'copters spin in the opposite direction: why?

and there is no prop on the ever popular car anology, when the engine is revved hard causing lurch.

piston drives the cranshaft which turns the prop. the piston moves down bwcause the explosion, which causes the movement because it forces the piston to move down using the block/ head as the base. the engine block is mounted securely to the vehicle, etc, etc, etc

helicopter have main gearbox fixed in the body which turns torque threw 90deg, so the engine has little to do with it with regards to its own flywheel effect as the load from pushing the blades one way is put into the main body by the gearbox case wile the tail rotor counters main body yaw and engine only counters input shaft load and is 90deg out of sync with you example!

If your then talking about vehicles like cars, trucks etc, agene the engine is mostly fixed to the gearbox which has its own mounts and the small amount of rock you get from sharply revving the engine when there is no load is minuscule in comparison to the amount of torque from the gearbox output shaft which will in fact twist the gearbox case and thus vehicle body/chassis the opposite way wile the engine that is rigidly fixed to it is only countering a smaller input shaft load.

Also with gearbox in the equation with lower output ratios resulting in increased output torque (like trucks, helicopter, turbo-props, etc etc etc) if you input say 500NM and get out 1500NM then ware dose the difference in output torque have an effect and ultimately go, via the gearbox case into the rest of the vehicle by any chance wile the engine is only countering a smaller input shaft load.
.

So forget the engine we are only interested in ware the force from pushing a prop one way ultimately ends up!

Originally Posted by Wolf_Rider

basic law of motion... "For every action there is an equal and opposite reaction"

http://www.aerospaceweb.org/question...s/q0015a.shtml

might help/ might not

you are 19 post behind

The effects of gearbox and high load and a vehicle twisting in the opposite direction to its propshaft

http://www.youtube.com/watch?v=pUVEH7AoEnw

[Wolf_Rider]

right then... well you get the picture of how torque rolls the plane in the opposite direction to the prop rotation

fixed mount - not much roll

no mount - a lot of roll

revv your (car) engine in neutral and watch what happens