RC Jets Discuss RC jets in this forum plus rc turbines and ducted fan power systems

Bob Cat Copy Falcon 120 Jet

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Old 04-24-2014, 08:50 AM
  #4726
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really, thanks.. all these years .. so the elevator provides thrust.. and the motor provides flight attitude?


thanks troll.


bet you mount your pusher props with the writing facing rearward too.
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Old 04-24-2014, 08:58 AM
  #4727
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If you moved this turbine to the front of the plane and bolted it on exactly the same angle with the tailcone facing down what would you call the thrust?
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Old 04-24-2014, 09:01 AM
  #4728
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Xairflyer

All these years as a flight engineer and you still don't know? shame on you.

Mike
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Old 04-24-2014, 09:22 AM
  #4729
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since you moved the direction of force forward ahead the CG the pitching moment changes.

this is no different than changing the angle of the stabilizer. as airspeed increases the force applied to it would also increase. this is why you need more control input as airspeed reduces.

vectored thrust changes the direction of force as related to the CG. not the total amount of thrust produced. now airspeed, lift, drag can all be effected. Weight stays the same(although fuel is being burned, unless its electric).


If you a flight engineer, must explain why the didn't move you to the control yoke. and left you to watch the dials.
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Old 04-24-2014, 09:40 AM
  #4730
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You got it right in the first line "pitching moment" the actual thrust angle dos'nt change, if the turbines tail is point down and as thrust is a reaction force then the thrust is up.

It is this up thrust that causes a planes nose to PITCH down if mounted behind the CG and Pitch up if mounted in front, that is why we normally add down thrust on our conventional tractor engine models.

You cant call it down thrust at the front and down thrust at the rear if the engine/turbine is mounted at a different angle.

Dont blame me blame Newton

And by the way I dont use pusher props on my rear engine aircraft, I change the timing of the engine so they can run in reverse and so use conventional tractor props .
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Old 04-24-2014, 09:43 AM
  #4731
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Quote:
Originally Posted by Tampaflyer View Post


If you a flight engineer, must explain why the didn't move you to the control yoke. and left you to watch the dials.
I have 23yrs on the control yoke as you call it, just thought I'd throw that in
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Old 04-24-2014, 01:02 PM
  #4732
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Xairflyer

Some people just can't be helped my aviator says it all.

Mike
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Old 04-24-2014, 01:28 PM
  #4733
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oh guys, all I wanna do is fly....
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Old 04-24-2014, 01:53 PM
  #4734
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Quote:
Originally Posted by sidajili View Post
oh guys, all I wanna do is fly....
Thats fine, but if by taking the comments made by those that have been involved with this airframe from the early days enables you to understand the airframe better is that not of benefit? its what we are all trying to do, knowledge and experience is useless unless it is passed on.

Mike

Last edited by BaldEagel; 04-24-2014 at 02:29 PM.
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Old 04-24-2014, 04:10 PM
  #4735
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Quote:
Originally Posted by Tampaflyer View Post
since you moved the direction of force forward ahead the CG the pitching moment changes.

this is no different than changing the angle of the stabilizer. as airspeed increases the force applied to it would also increase. this is why you need more control input as airspeed reduces.

vectored thrust changes the direction of force as related to the CG. not the total amount of thrust produced. now airspeed, lift, drag can all be effected. Weight stays the same(although fuel is being burned, unless its electric).


If you a flight engineer, must explain why the didn't move you to the control yoke. and left you to watch the dials.
I agree with you Tampaflyer. All I know is I point the nozzle down = down thrust I point the nozzle up = up thrust and I will point my nozzle down on my Navy Cat. Good thing they don't steer rockets.
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Old 04-24-2014, 04:23 PM
  #4736
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They do steer rockets. How do you think they stay on course?
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Old 04-24-2014, 05:05 PM
  #4737
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Quote:
Originally Posted by Woketman View Post
They do steer rockets. How do you think they stay on course?
I guess you didn't get my tongue-in-cheek joke who "they" were. By the way this is all in good fun.
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Old 04-24-2014, 05:13 PM
  #4738
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Quote:
Originally Posted by Woketman View Post
They do steer rockets. How do you think they stay on course?
I guess you didn't get my tongue in cheek about who "they" were.(the 2 gentleman from across the pond that said pointing the exhust nozzle down is up thrust). This is all in good fun.LOL
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Old 04-24-2014, 06:46 PM
  #4739
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Joseph:
I found that if you raise the engine about 1/4" at the front of the mount you will get the needed down thrust. Also, one other thing to note is that elevator neutral on this plane is obtained with a straight edge along the TOP of the stab and the top of the elevator flush with the straight edge. For landing I use 35 deg. of flaps and this requires approximately 3/16" of DOWN elevator. The Tornado manual says to use up elevator mix with the 35 deg. of flaps but trust me this is not correct (did that on the first flight and the plane hovered for a few seconds before I removed the flaps, throttled up and flew out of the HOVER) Let me know if I can be of any assistance. You can PM me if you like.

Ed
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Old 04-25-2014, 02:34 AM
  #4740
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[QUOTE=Deleted post[/QUOTE]

EDIT: due to original quoted post being deleted by mods.

Mike

Last edited by BaldEagel; 04-26-2014 at 07:55 AM.
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Old 04-25-2014, 03:57 AM
  #4741
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Quote:
Originally Posted by toolmaker7341 View Post
I guess you didn't get my tongue in cheek about who "they" were.(the 2 gentleman from across the pond that said pointing the exhust nozzle down is up thrust). This is all in good fun.LOL
You are not looking at this correctly, Thrust is a reactive force, it is what it makes the object do, a rocket sitting pointing up, the jet blast out the bottom, makes the rocket go up, that is why it is referred to as up thrust.
The rocket thrusted upwards, You thrust up, you thrust forward.
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Old 04-25-2014, 04:50 AM
  #4742
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Quote:
Originally Posted by Xairflyer View Post
You are not looking at this correctly, Thrust is a reactive force, it is what it makes the object do, a rocket sitting pointing up, the jet blast out the bottom, makes the rocket go up, that is why it is referred to as up thrust.
The rocket thrusted upwards, You thrust up, you thrust forward.
I guess we can agree to disagree but if the said rocket is traveling horizontally to the earth (ie: our jet aircraft) and you want to go up where do you point the nozzle? UP and pointing the nozzle up is up thrust. This is a topic that we can discuss untill the snakes take the next plane back to Ireland.I would agree with you if we were talking about a tractor propeller but we are talking in you words thrust "reactive force". We can still be friends.By the way I've been to your country (1968) and it was very bueatiful.
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Old 04-25-2014, 07:33 AM
  #4743
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You guys are gonna get the thread closed....
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Old 04-25-2014, 09:40 AM
  #4744
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Maybe this will help. Ive found that sometimes pictures can help a lot when words alone can't convey the physics. In this case thrust, mass expelled and the resultant pitch.
Cheers.

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Old 04-25-2014, 11:02 AM
  #4745
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At the risk of getting beat up, might I suggest that the issue of up thrust vs down thrust be debated on its own thread. This thread was started to discuss the relative merits/flying/trimming of the Falcon 120, Tornado, Super Falcon V3, Navy Cat, Kestrel, etc.

Sincerely,
Ed
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Old 04-25-2014, 12:05 PM
  #4746
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I agree with Ed. Let's get this thread back to focusing on the Falcon and its kin. I think that we all know what is meant when this discussion comes up regarding engine mounting angle. If you would like to continue to discuss up/down thrust please create a new thread.
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Old 04-25-2014, 03:36 PM
  #4747
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thank you for the replies, didnt mean to start a battle, I will put DOWN thrust in my turbine and fly it...thanks again
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Old 04-26-2014, 06:53 AM
  #4748
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This was a spirited discussion on thrust angle of the Falcon/Navy Cat, NO flaming,name calling or derogitory statments were made by any member. I lost my first turbine on maided because I was told on RCU to put in "Down" thrust by pointing the nozzle "up"or the nose of the turbine down and I don't want anyone getting the wrong idea from this thread. Use the picture of gsoav8r and you won't be wrong. I would consider Baldeagle and Xairflier as friends and hope they would consider me as theirs. This IS on topic as we were trying to clear up any misunderstanding about thrust angles for the falcon/Navy Cat. Do we want a new flyer crashing or quitting jets because they were misinformed or misunderstood what was being written here? Now This reply is off topic but needed explaination.
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Old 04-26-2014, 12:09 PM
  #4749
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Quote:
Originally Posted by Hot islanders View Post
All this just confuses things more far better to keep it simple and describe so as no confusion

just have the front of the turbine higher than the rear by a small amount. Can't be any more simple than that

Some people have a knack of complicating that which is simple
Reread my post. Doesn't get any simpler than the picture I refered to in post #4746 that gsoav8r had posted.
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Old 04-26-2014, 12:14 PM
  #4750
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I don't understand why this is so confusing, down thrust just like down elevator...done no need to discuss it further
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