Sport Pilot Drifter story

[farri]

Richard, believe me! you and I won`t have a falling out,( as you put it ), over this! That would be childish.

 

I`ve stated several times that the prop shaft in both pusher and tractor must be turning in the same direction and the prop must be able to be bolted from both sides of the hub face yet you continue to talk about the shaft of a pusher going in one direction and the shaft of the tractor going in the opposite direction.

 

I`ve already told you I know exactly what you are saying and in the scenario you present you are correct, however, you can`t seem to grasp what I`m saying.

 

Other than to continue explaining what I`ve alread said previously, I fail to see what else I can say.

 

Frank.

 

 

[Teckair]

OK spoke to Peter at Bolly who explained that yes a Bolly prop will do both tractor and pusher but you have to rotate the blades 180 degrees in the hub as well as refit the prop with the opposite hub face towards the gearbox to make the change.If you cannot do that (as with any fixed pitch prop) it will not work.

 

Richard.

Right now I am trying to see how what Peter has said could work and so far cannot see how. Because Bolly props are well known and I feel he should be right about this I am mystified about it. Watch this space!

 

 

[farri]

Richard, Did you ask Peter if the same prop could be used for both pusher and tractor,provided the the prop shaft in each case was turning in the same direction?

 

Frank

 

 

[Teckair]

Richard, Did you ask Peter if the same prop could be used for both pusher and tractor,provided the the prop shaft in each case was turning in the same direction?Frank

Yes we were talking about using a 912 as pusher or tractor meaning the prop shaft can only go in on direction same as a 582 with a gearbox reduction the prop shaft always goes in the same direction in relation to the motor.

 

 

[farri]

Richard, Sorry but I can`t understand what you mean.

 

To my knowledge, the 912 doesn`t require a gearbox so if fitted as a pusher, when viewed from the tail looking forward, the crankshaft ( Prop Shaft ) will be turning anti clockwise. If the 912 is mounted as a tractor, when viewed from the tail, looking forward, the Prop Shaft will turn clockwise.

 

The Rotax 582 does require a gearbox and when viewed from the tail looking forward, the prop shaft will be turning clockwise. The crankshaft of the 912 as a tractor will be turning clockwise. Same direction in both cases.

 

If a 582 is fitted as a tractor, say, to a thruster and a belt drive is fitted to the engine, the prop shaft will turn clockwise, same direction as the 582 with gearbox, as a pusher.

 

Frank.

 

 

[Teckair]

"To my knowledge, the 912 doesn`t require a gearbox so if fitted as a pusher, when viewed from the tail looking forward, the crankshaft ( Prop Shaft ) will be turning anti clockwise. If the 912 is mounted as a tractor, when viewed from the tail, looking forward, the Prop Shaft will turn clockwise.. ....."

 

Frank all 912s have a gearbox, the crankshaft in a 912 rotates the opposite way to a 582 which means so does the prop shaft.

 

You are correct about the rotation direction of the prop shaft on the 912.

 

"The Rotax 582 does require a gearbox and when viewed from the tail looking forward, the prop shaft will be turning clockwise. The crankshaft of the 912 as a tractor will be turning clockwise. Same direction in both cases....... "

 

I think what you are saying is correct if you meant the 582 as a pusher and the prop shaft on the 912..

 

"If a 582 is fitted as a tractor, say, to a thruster and a belt drive is fitted to the engine, the prop shaft will turn clockwise, same direction as the 582 with gearbox, as a pusher...."

 

Yes I agree with that

 

Pity I can't do selective quoting maybe someone can help me out there?

 

Richard.

 

 

[Teckair]

OK after careful thought and making a cardboard cut out of the prop profile and going into the hanger and checking with the plane I think I have understood what Peter from Bolly said to me yesterday.

 

Not surprisingly what he said is quite correct, one thing I said that was wrong is you need to change which face on the hub that faces the engine in fact you do not change which face on the hub that faces the engine that part stays the same for both tractor and pusher.

 

This only works with props where you can rotate the blades in the hub 180 degrees.

 

 

[farri]

Pity I can't do selective quoting maybe someone can help me out there?Richard.

Richard,Try this. Click the reply button of the post you want to quote. If you only want to quote a sentence, delete everthing else, leaving only the sentence, as I`ve done above. When you want to quote another part of the same post, Click the reply button of the post and again,deleate everything except what you want to quote, as I`ve done bellow.

 

Pity I can't do selective quoting maybe someone can help me out there?Richard.

When you want to quote from a different post or someone lese`s post, click the reply button of the post and go through the same steps. If you want to quote the whole post, leave it as it is.

 

If you put a prop on backwards it still works in the same sense but with the efficiency reduced. Like a lifting wing section flying upside down. nev

With the recent changes to the this site, there may be other ways of doing the same thing, you would need to ask Ian.

 

This is the only way I know how to do it. I hope I`ve helped.

 

Frank.

 

 

[facthunter]

The relationship of the prop to the airflow stays the same . The curved side of the blade faces the airflow (front) When the engine goes from tractor to pusher it has to be reversed on the hub. The engine must run the other way then. because with that prop it will always draw air to the engine, unless the rotation of the engine is reversed. Forget gearboxes (which reverse the engines rotation usually) and belts don't. That just complicates it. Consider any particular engine / gearbox combination as a unit. for the purpose of discussion.Nev

 

 

[Teckair]

This is the only way I know how to do it. I hope I`ve helped.

 

Thanks for that Frank I have wondered how to do that for a long time.

 

 

[Teckair]

Mmmm didn't really work must have done something wrong, might have another go.

 

 

[Teckair]

This is the only way I know how to do it. I hope I`ve helped.

One more go.

 

 

[Teckair]

Wow excitement plus it worked!!

 

 

[dazza 38]

Wow excitement plus it worked!!

nice job

 

 

[farri]

Wow excitement plus it worked!!

Goodonya Richard, You`re on your way!

 

Frank.

 

 

[driftamark]

Hi all after playing with prop and keeping the rotation the same way, to go from 1 face to the other face of the prop hub , the leading edge of the of the blade on a pusher becomes the trailing edge of the tractor.

 

Mark

 

 

[driftamark]

Hi me again to clarify I used a brolga prop and a 582 from the drifter and to turn them around and use them as a tractor with the prop hub on the other face the prop would not work effectively, the leading edge of the blade becomes the trailing edge of the tractor and the blade shape is backwards. the shape of brolga blade changes from leading edge to trailing edge, round on the leading sharp on the trailing, you have the flat side of the prop to the rear of the plane, and it will pull you along but you wont get the thust that you need. You have to play with a prop because you dont get the same perspective playing with black boards.

 

Mark.

 

 

[Teckair]

You have to play with a prop because you dont get the same perspective playing with black boards.Mark.

Yes Mark that is quite right and if you don't do that then it will be difficult to understand as has been shown on this thread. If you check again you will see to turn a pusher prop around and use the other face it will still act as a pusher and not a tractor.

 

 

[driftamark]

Hi yes the helix stays the same no matter which face is connected to the gearbox the air is blown away from the motor.

 

Mark

 

 

[Teckair]

Now we are getting somewhere, thanks Mark I am glad you contributed.

 

 

[farri]

Hi all after playing with prop and keeping the rotation the same way, to go from 1 face to the other face of the prop hub , the leading edge of the of the blade on a pusher becomes the trailing edge of the tractor Mark

Mark Please go and try this..... Stand behind the Drifter, take the prop off, do not turn it around and keep the right hand blade in your right had, walk to the front of the aircraft keeping the prop facing exactly the same way it was when you took it off, you should be facing forwards..... Take a good look at leading edge of the prop then please get back on here and tell me which way the leading edge is facing.

 

Frank.

 

 

[M61A1]

I'm going to try and clarify this....... Farri is quite right about what he is saying. He is talking about the propeller only, not the engine. Teckair is right, if you take the whole powerplant assy and just turn it around. Of course if you take the prop and engine from the back of your drifter and face it forwards it will propel you backwards,and with even less thrust if you're dumb enough to put the trailing edge first, but that same pusher propeller can be removed from the drifter and put on the front of , say , a thruster, using a belt drive robin (which because it is belt driven, turns the opposite direction), and it will work at normal efficiency as a tractor prop. It doesn't matter whether it's on the front or back, as long as you turn it in the correct direction for your application.

 

 

[Teckair]

I'm going to try and clarify this....... Farri is quite right about what he is saying. He is talking about the propeller only, not the engine. Teckair is right, if you take the whole powerplant assy and just turn it around. Of course if you take the prop and engine from the back of your drifter and face it forwards it will propel you backwards,and with even less thrust if you're dumb enough to put the trailing edge first, but that same pusher propeller can be removed from the drifter and put on the front of , say , a thruster, using a belt drive robin (which because it is belt driven, turns the opposite direction), and it will work at normal efficiency as a tractor prop. It doesn't matter whether it's on the front or back, as long as you turn it in the correct direction for your application.

Yes that is understood but Farri has said that there are no pusher or tractor specific props (which there are) and the one prop will do both pusher and tractor on the same engine/reduction drive combination and he has not said you had to go to a different engine/reduction drive combination with the prop shaft turning in the opposite direction to make it work.

 

 

[M61A1]

Richard, I have said from the very begining, the prop shaft must be turning in the same direction in both configurations.

 

At no time have I sugested putting a prop from a shaft turning clockwise to a shaft turning anticlockwise and expecting the same result. I am aware that not all props can be bolted on either side of the hub.

 

Farri's post #42 (above)

 

I can only assume you took this as using the same engine, I took it to mean that it is relative to the shaft. Clockwise is clockwise, front or rear makes no difference.

 

 

[Teckair]

Richard, I have said from the very begining, the prop shaft must be turning in the same direction in both configurations.At no time have I sugested putting a prop from a shaft turning clockwise to a shaft turning anticlockwise and expecting the same result. I am aware that not all props can be bolted on either side of the hub.

Farri's post #42 (above)

 

I can only assume you took this as using the same engine, I took it to mean that it is relative to the shaft. Clockwise is clockwise, front or rear makes no difference.

I thing the biggest problem is confusion and things being lost in the communication of posts. Have you read all the posts from the beginning? We have been talking about the same engine/reduction/ prop shaft direction in most instances as in the 912 for example.

.