trying2fly
I have a Hawk Sky that has a pusher prop and the  motor appears to me mounted about 5 degrees towards the ground?  I have built a Flying Wing and I am not certain what angle to mount the motor and in what direction?   It does seem if the motor is pointed up the plane would fly up?  Not so with the HawkSky?  Please ck my drawing and give me advice.  Thanx! Rise or Fall 003.jpg 
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Wildthing
By your picture I would say it will nose dive on you under power. Don't quote me but unless the motor is above or below the thrust line it should be fairly straight with the axis line. If say the motor was above the wing you would basically angle it toward the cg point, so down in that case. Now maybe the wing has some stupid pitch characteristics to it and this is to compensate for it. I would say balance it and try some glide tests not using any power.
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trying2fly
Wildthing wrote:
By your picture I would say it will nose dive on you under power. Don't quote me but unless the motor is above or below the thrust line it should be fairly straight with the axis line. If say the motor was above the wing you would basically angle it toward the cg point, so down in that case. Now maybe the wing has some stupid pitch characteristics to it and this is to compensate for it. I would say balance it and try some glide tests not using any power.
         Thanx Jeff...by the way... I spent the evening enjoying your flights on Utube.  Thanx for the link...they were fun to see!! chas
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Wildthing
trying2fly wrote:
         Thanx Jeff...by the way... I spent the evening enjoying your flights on Utube.  Thanx for the link...they were fun to see!! chas


I wish I had the time to edit the videos and cut out all the crap but that just takes to long. 😉 

This plane are you building it? If you are do the glide testing before you put all the heavy stuff into it like motor, esc and battery. Add ballast where ever you need to to get it balanced on the cg mark and start your glide tests.  If it glides nicely put the motor mount on straight, Once flying and you notice it maybe pitch up or down  when you give it full throttle you can always shim the motor. 

Cheers
Jeff
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DualDesertEagle
I can only agree with pointing the motor axle at the CG. On a flying wing u don't have the stabilizing tail so a mismounted motor has more of an impact on the plane's behaviour. So if the motor is pointed prop end down the plane's gonna want to nose dive and vice versa. with the motor pointed towards the CG it could probably even be mounted on top and thus thrust straight downwards without causing much of a disturbance other than pushing the whole plane down, tho it would of course be totally useless.


In fact, the reason why the Space Shuttle's engines were angled so much is much the same, namely that the CG was not within the Shuttle but within the orange tank. With the engines mounted straight it would've pitched down, and probably hard enough at that to make the whole thing crash shortly after launch.
[tg2reJC] 
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bogusbandit56
trying2fly wrote:
I have a Hawk Sky that has a pusher prop and the  motor appears to me mounted about 5 degrees towards the ground?  I have built a Flying Wing and I am not certain what angle to mount the motor and in what direction?   It does seem if the motor is pointed up the plane would fly up?  Not so with the HawkSky?  Please ck my drawing and give me advice.  Thanx!
The Hawk sky and flying wing would be completely different to set up,  the prop on your drawing will cause a pusher to nose down and if fitted to a Bixler or Hawk Sky it would be impossible to launch because of violent pitching down.
The reason the HS motor is pointing down toward the CG on the wing is because if it were straight it would force the nose down violently under power.
All those Bixler and Hawk Sky type high mounted pushers have the motor mounted pointing at the COG to prevent nose diving.
I have found the best place to mount a motor on a flying wing is on the centerline of the wing. All flying wings need reflex to fly so keeping the motor neutral helps, if the plane zooms you can dial in some down on the motor.
The reason the Horten 7 had the props pointing behind the CoG was because the motors were buried in the wing to keep the drag to a minimum and that was the only way to do it.
I have a Skywalker Falcon and the motor is mounted above the wing, this makes the plane pretty well balanced during flight but tends to push the nose down when launching due to lack of speed and lift.
Rise or Fall 003.jpg 
Wot, no Depron?
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bogusbandit56
You will notice on the maiden launch of my Falcon the wing noses in due to the high mounted motor but the wing flies very nicely when it has airspeed.
What I do is add up trim for the launch and then trim the plane out for level flight once in the air.
When building flying wings the most important thing is to have reflex, which is basically up elevon or the wing won`t fly.
There is very little margin of error with the CoG on a flying wing so you need to pay attention to that as well.
This wing is a powered glider and has a fairly high aspect ratio wing you will notice that the plane tip stalls at the end of the video as I was flying to slowly when I made the turn. Try to avoid that by keeping up the speed in the turns.
Wot, no Depron?
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trying2fly
Wildthing wrote:
                  The motor I am using is from an old HawkSky.  It had been mounted at an angle to a piece of wood with epoxy. (I used it with a homemade HawkSky).  This motor/wood mount/epoxy combo had a built in angle so when I began to mount it on my wing to a block that was in line with the fuselage horizontally and vertically it had an angle.  Rather than struggle taking the motor off of the old wood mount I was going to just stick it on the wing.  That is why I wanted to know which way to mount the motor.  If I had a new motor I would have just mounted it on the wing in a straight line.  Now I see that I am best to just shim it out straight.  I did learn from this and I thank all of you.  chas

I wish I had the time to edit the videos and cut out all the crap but that just takes to long. 😉 

This plane are you building it? If you are do the glide testing before you put all the heavy stuff into it like motor, esc and battery. Add ballast where ever you need to to get it balanced on the cg mark and start your glide tests.  If it glides nicely put the motor mount on straight, Once flying and you notice it maybe pitch up or down  when you give it full throttle you can always shim the motor. 

Cheers
Jeff
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trying2fly
I can only agree with pointing the motor axle at the CG. On a flying wing u don't have the stabilizing tail so a mismounted motor has more of an impact on the plane's behaviour. So if the motor is pointed prop end down the plane's gonna want to nose dive and vice versa. with the motor pointed towards the CG it could probably even be mounted on top and thus thrust straight downwards without causing much of a disturbance other than pushing the whole plane down, tho it would of course be totally useless.


In fact, the reason why the Space Shuttle's engines were angled so much is much the same, namely that the CG was not within the Shuttle but within the orange tank. With the engines mounted straight it would've pitched down, and probably hard enough at that to make the whole thing crash shortly after launch.
[tg2reJC] 
Really nice illustration and very informative.  Thank you so much.  Jeff and Ian and you are extremely knowledgeable when it comes to CG and balance .  Lucky for me!!Thank you very much!!
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trying2fly
You will notice on the maiden launch of my Falcon the wing noses in due to the high mounted motor but the wing flies very nicely when it has airspeed.
What I do is add up trim for the launch and then trim the plane out for level flight once in the air.
When building flying wings the most important thing is to have reflex, which is basically up elevon or the wing won`t fly.
There is very little margin of error with the CoG on a flying wing so you need to pay attention to that as well.
This wing is a powered glider and has a fairly high aspect ratio wing you will notice that the plane tip stalls at the end of the video as I was flying to slowly when I made the turn. Try to avoid that by keeping up the speed in the turns.
    Your Falcon is a gorgeous plane and flies like a dream.  You make me want to throw my wing in the trash!!LOL....I am very surprised to learn how sensitive this thing is going to be to CG.  I will show you my progress ...if you can call it that if the weather will clear some.  We have had a wk and half of 50-70 Mph winds day and nite here but they are to be light today (less than 20Mph).   I dont know how you make those beautiful bends in the foam but you are truly  sharp with your building skills.  Good for you!!  chas
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bogusbandit56
Hi Chas , thanks for the compliment but the Skywalker Falcon is a store bought plane. I can`t take any credit for the beautiful lines although if I were to design a wing like this it would be the same shape🙂
You will probably get more satisfaction building and successfully flying your own planes, so don`t worry about the quality. My builds don`t bare close scrutiny and compared to other builders on this site they are pretty poor. Having said that they usually fly pretty well😜
https://www.banggood.com/Skywalker-Falcon-1340mm-EPO-Flying-Wing-FPV-RC-Airplane-KIT-p-1137082.html?cur_warehouse=CN
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DualDesertEagle
trying2fly wrote:
We have had a wk and half of 50-70 Mph winds


Make that 2 weeks and add heavy rain in the second, then u've got the weather around here, and being basically locked inside is ruining my mood day after day and spending most of my time playin' video games ain't doing much to help that matter, but it's the best thing I can do to kill my boredom.

On the plus side, there's a kind of game I've become STUPIDLY good at, notice all the gold cups and finished challenges:
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trying2fly


Make that 2 weeks and add heavy rain in the second, then u've got the weather around here, and being basically locked inside is ruining my mood day after day and spending most of my time playin' video games ain't doing much to help that matter, but it's the best thing I can do to kill my boredom.

On the plus side, there's a kind of game I've become STUPIDLY good at, notice all the gold cups and finished challenges:
   Rats....the game was disabled by the owner and unavailable here!!  Have you tried pool on Gametwist. com?  When you do let me know when you are on!!!  I pass these windy times trying my hand at it and I am SLOWLY getting better..chas
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bogusbandit56
I consider myself too old to go online gaming and  was very disappointed recently to find my new type of telly is not compatible with my old Sony Playstation One. I was a wizard at Grand Turismo. 🙁 I also have a Betamax video player but no longer have the strength to pick it up and take down the tip.
Wot, no Depron?
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DualDesertEagle
trying2fly wrote:
   Rats....the game was disabled by the owner and unavailable here!!  Have you tried pool on Gametwist. com?  When you do let me know when you are on!!!  I pass these windy times trying my hand at it and I am SLOWLY getting better..chas


The game itself should actually still be online, but the problem is that the seemingly only browsers supporting Unity Web Player (namely Firefox and Chrome) have discontinued their support for it and thus the game is unplayable. Of course it could be that the game has been taken down for that exact reason.

And I know some other fun games that used Unity Web Player and are of course also unplayable. 


I'm not really a fan of pool, instead I'm currently playin' Far Cry 5's campaign and probably going back to my usual multiplayer shooters like Battlefield and Planetside 2 after I'm done with that.
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