Counter vs Co-Rotating Props

[Masherbrum]

Flip the engine over and it still spins the same way. Roll a plane until it's inverted and that prop still turns the same direction!

 

To get it spinning the other way you've have to spin it around to a pusher. THAT's a setup (left push, right pull) I don't even wanna contemplate!

No.   Flip an identical engine over and the COG of the engine changes.   Do it with ANY engine, or get your hands dirty for a change and put one on an engine stand.   The weights are different from top to bottom on a horizontal 1/2 way point, it's actually quite simple Krusty.   I am not discussing Radial Engines either.   I'm talking Inline Engines.  

Keep worrying about fictional propeller setups and rotations that I have never once mentioned though.  

[Krusty]

I'm not talking about CoG... I'm not talking about being able to run inverted, oil starvation or any of that... The comment was made to "flip the engine over" so it would have counter-rotating props... No matter what way you flipped it, it's still spinning the same way. The blades still have the same "handed-ness"!

It's all a moot point because you roll a plane upside down and the blades don't magically spin backwards!

[bozon]

I'm not talking about CoG... I'm not talking about being able to run inverted, oil starvation or any of that... The comment was made to "flip the engine over" so it would have counter-rotating props... No matter what way you flipped it, it's still spinning the same way. The blades still have the same "handed-ness"!

I think he meant to turn it around and make the shaft come out of the back end. This is not so simple modification.

Also, having counter rotating props means a different kind of prop for each engine - those are not reversible either.

[Masherbrum]

I'm not talking about CoG... I'm not talking about being able to run inverted, oil starvation or any of that... The comment was made to "flip the engine over" so it would have counter-rotating props... No matter what way you flipped it, it's still spinning the same way. The blades still have the same "handed-ness"!

It's all a moot point because you roll a plane upside down and the blades don't magically spin backwards!

....and you're assuming what you say is what I meant.   You're wrong and missed the point.   Again, I never GAF about the props.   Inverting one engine, as someone else mentioned, would cause disturbance in a design.   Because you are disrupting the COG.

You are going off on some tangent that has absolutely no bearing.   

[thorsim]

flipping engine over is not what i meant, mash understood right away, krusty did not.

how much work reversing the prop fittings/gears, flipping the exhaust, adjusting the water cooling if there is one depends on the engine but none of that would necessarily require a total redesign of the entire engine.  i do not know but i could imagine an engine that was designed so one could have the prop mounted on either side after all the shaft/s runs all the way along the row of pistons.  i would be surprised if this had never been done, in fact i would be very curious how allison managed to offer the rotation option on their engines. 

as far as how much the C of G would effect the airframe, i do not know that either but after looking at many designs both radial and inline i find that the entire engine is often forward of the wing and i am not convinced that the C of G differences in the engine would be terribly significant to the overall balance of the aircraft and certainly would be correctable with a bit of work. 

would it be easier than an entire factory retool? probably.  would a gearing solution be easier still? probably. 

gentlemen this is just a hypothetical conversation, no need to get nasty with each other about it.

its just fun with our imaginations is all ...

+S+

t 

 

[Krusty]

You say "flip" something, it means turn it upside down. You say "switch" something then it might apply to what you're discussing.

You flip cars over. You flip planes on their backs. You flip pancakes. You flip burgers.

You don't use that term to mean "turn a prop the other direction" -- it's not what the word means.

Sorry, but you weren't making sense and I had to reply.


P.S. I think Karaya's getting stressed. To help de-stress, I'm going to clarify something... You may be under the impression I'm targetting you because I quoted you. In fact the original comment was from thorsim: "wonder why they just didn't just flip the engines to counter rotate the props" and I quoted you because yours was the direct reply to him. YOU took it to mean turning the engine upside down (same as I did), but failed to grasp the point that he was talking about flipping it upside down in order to reverse the direction of the blades' spinning.

So, once again:

"wonder why they just didn't just flip the engines to counter rotate the props "  <-- couldn't let that go without SOME comment.

[thorsim]

You say "flip" something, it means turn it upside down. You say "switch" something then it might apply to what you're discussing.

You flip cars over. You flip planes on their backs. You flip pancakes. You flip burgers.

You don't use that term to mean "turn a prop the other direction" -- it's not what the word means.

Sorry, but you weren't making sense and I had to reply.


P.S. I think Karaya's getting stressed. To help de-stress, I'm going to clarify something... You may be under the impression I'm targetting you because I quoted you. In fact the original comment was from thorsim: "wonder why they just didn't just flip the engines to counter rotate the props" and I quoted you because yours was the direct reply to him. YOU took it to mean turning the engine upside down (same as I did), but failed to grasp the point that he was talking about flipping it upside down in order to reverse the direction of the blades' spinning.

So, once again:

"wonder why they just didn't just flip the engines to counter rotate the props "  <-- couldn't let that go without SOME comment.

ADOBE agrees with me in the ability to flip along both the vertical and horizontal axis ...



probably because ...

flip  (flp)
v. flipped, flip·ping, flips
v.tr.
1. To throw or toss with a light brisk motion: flipped me the ball; flipped his hair out of his eyes.
2. To toss in the air, imparting a spin: flip a coin.
3.
a. To turn over or around, especially with a light quick motion: flip over a card; flipped the tape to play the other side.
b. To turn through; leaf: flipped the pages of the report.
4. To strike quickly or lightly; flick.
5. To move or act on with a quick motion: flip a switch; flipped open her briefcase.
v.intr.
1. To turn over: The canoe flipped over in the rapids.
2. To turn a somersault, especially in the air.
3. To move in twists and turns: fish flipping about in the net.
4. To move quickly and lightly; snap: The lid flipped open.
5. To leaf; browse: flipped through the catalogue.
6. Slang
a. To go crazy. Often used with out.
b. To react strongly and especially enthusiastically: She flipped over the new car.
n.
1. The act of flipping, especially:
a. A flick or tap.
b. A short, quick movement: a flip of the wrist.
c. A somersault.
2. Informal A reversal; a flipflop.
3. A mixed drink made with any of various alcoholic beverages and often including beaten eggs.
adj. flip·per, flip·pest Informal
Marked by casual disrespect; impertinent: a flip answer to a serious question.
Idiom:
flip (one's) lid Slang
1. To react strongly, as with anger or enthusiasm.
2. To go crazy.

[Masherbrum]

You say "flip" something, it means turn it upside down. You say "switch" something then it might apply to what you're discussing.

You flip cars over. You flip planes on their backs. You flip pancakes. You flip burgers.

You don't use that term to mean "turn a prop the other direction" -- it's not what the word means.

Sorry, but you weren't making sense and I had to reply.

P.S. I think Karaya's getting stressed. To help de-stress, I'm going to clarify something... You may be under the impression I'm targetting you because I quoted you. In fact the original comment was from thorsim: "wonder why they just didn't just flip the engines to counter rotate the props" and I quoted you because yours was the direct reply to him. YOU took it to mean turning the engine upside down (same as I did), but failed to grasp the point that he was talking about flipping it upside down in order to reverse the direction of the blades' spinning.

So, once again:

"wonder why they just didn't just flip the engines to counter rotate the props "  <-- couldn't let that go without SOME comment.

Well then sound off when you're doing the quoting.      Thorsim is incorrect on flipping an engine upside down, the crankshaft will still spin the same way.

[W7LPNRICK]

Flip the engine over and it still spins the same way. Roll a plane until it's inverted and that prop still turns the same direction!

 

To get it spinning the other way you've have to spin it around to a pusher. THAT's a setup (left push, right pull) I don't even wanna contemplate!

I think he meant flipping it end to end. If an engine was built with a fly-wheel on both ends, it would be reversible. 

[Masherbrum]

I think he meant flipping it end to end. If an engine was built with a fly-wheel on both ends, it would be reversible. 

 

[thorsim]

I think he meant flipping it end to end. If an engine was built with a fly-wheel on both ends, it would be reversible. 

exactly ...

or if you "moved" the flywheel mechanism to the other side of the engine, or if the shaft protruded through the block on both sides so either rotation was an option ...

remember those little electric motors where the shaft passed through on both sides that you could "flip" to produce the drive direction you wanted  



mash way to follow krusty's fail even after i posted the definition of the word flip ...

maybe you posted before you caught up with the thread

[AWwrgwy]

mash way to follow krusty's fail even after i posted the definition of the word flip ...

maybe you posted before you caught up with the thread

Funny, but in the definition given, except for the word "around", all the examples given seem to pertain to "over" or "up and down".

Semantics.


wrongway

[thorsim]

Funny, but in the definition given, except for the word "around", all the examples given seem to pertain to "over" or "up and down".

Semantics.


wrongway

what do you do with a switch ...

[colmbo]

what do you do with a switch ...

Turn it on and off.

[thorsim]

Turn it on and off.