Help on Angle of Thrust

[Ghostfit]

Anyway, there aren't many folks who would really enjoy engaging this hobby alone without any friends. It'll at most take me an hour or so flying alone at the slope before I head home. It is simply too boring to do this hobby alone without kicking each other's backside!

Need any help ? ...I specialise in nose cones errm...as you say, D**do !

No Tony, you are STILL agreeing with me. In my earlier post, I already mentioned the exception of 3D planes. That should already indicates that my further explainations are meant for gliders, trainers, Pylon racers and most sport models.

See post #7.

My Strega? Where are the PINK servos?

My mistake ! Didn't read all the way from the begining ! ...Okay, we totally agree !

I only got 'Blue' servos ! ...HXT900, you want ?

Back to Airplanes:
Lower the KV ,your plane will have awesome static thrust but will never fly fast (Joeyap states plane will never fly faster than air velocity the prop produced)
Higher the KV you plane will have pathetic static thrust, normally blades will stall under static bench test thus the poor results. (Joeyap states: the additional ram air forward of the prop can unstall the blades and the system will suddenly spring to life and accelerate much faster and reaching speeds beyond what the first setup can achieve)

Not entire true. You forgot about the load being driven. For lower Kv motors, you still can use a higher pitch prop to match the prop velocity of a Higher KV motor driving a lower pitch prop.

For cars, the diameter of the tires and the axle speed also determines the maximum speed a car can go.

...and also not forgeting the cells count, it is possible that a lower KV motor with enough voltage (Cells) can spin faster than a higher kv motor.
But EP motors are usually wound according to their intended usage.

[Raven]

I only got 'Blue' servos ! ...HXT900, you want ?

lol.... Tony, we'll strip the servos off the Barbie Doll radio control car for Joe to use. Go PINK!!!

[viper1990]

Back to Airplanes:
Lower the KV ,your plane will have awesome static thrust but will never fly fast (Joeyap states plane will never fly faster than air velocity the prop produced)
Higher the KV you plane will have pathetic static thrust, normally blades will stall under static bench test thus the poor results. (Joeyap states: the additional ram air forward of the prop can unstall the blades and the system will suddenly spring to life and accelerate much faster and reaching speeds beyond what the first setup can achieve)

Not entire true. You forgot about the load being driven. For lower Kv motors, you still can use a higher pitch prop to match the prop velocity of a Higher KV motor driving a lower pitch prop.

For cars, the diameter of the tires and the axle speed also determines the maximum speed a car can go.

...and also not forgeting the cells count, it is possible that a lower KV motor with enough voltage (Cells) can spin faster than a higher kv motor.
But EP motors are usually wound according to their intended usage.

Hey look, a qoute in a qoute in a qoute

Ah yes..., of course, i missed out those infomation too like wheel diameter...cell count...etc...

Anyways.. i think some beginners won't be able to take in soooo many infomation in this thread ... there are many factors to take into consideration.

The really really best way to learn about KV/motor/prop/cells... is to put them into practical use and do trial and errors and find out the best combination. But of course, with some theoretical background from the experts in the forum.

Lastly.. Isn't this thread about thrust angle? lol...

[joe yap]

Have we confused the threadstarter already ?

If not, I am already confused with all the technical talkings...

This week is reserved for calculation up to 21 KV only. Anything more is "pok" lah...

Huat Ah ! Bun Luck !

The thread starter is already confused at the beginning. Thrust angle and power are 2 totally different things. If you really take your time to read and digest into the discussion, things should be pretty clear. Afterall, we are all using school textbooks to explain. I didn't even study at University. Anyway, all these informations can be picked up from RC magazine articles, published from time to time.

[joe yap]

Hey look, a qoute in a qoute in a qoute

Ah yes..., of course, i missed out those infomation too like wheel diameter...cell count...etc...

Anyways.. i think some beginners won't be able to take in soooo many infomation in this thread ... there are many factors to take into consideration.

The really really best way to learn about KV/motor/prop/cells... is to put them into practical use and do trial and errors and find out the best combination. But of course, with some theoretical background from the experts in the forum.

Lastly.. Isn't this thread about thrust angle? lol...

I understand where you are coming from, but I am a little too conservative to generalise things like this. For example, Mave quoted a motor at 800Kv, which sounds pretty low, comparing the smaller motors we used. However, the motor is designed for upto 12S, which the free load rpm can spin up to around 40000+RPM! At this speed, even a prop with smallest pitch in the market will turn the model into a speed monster on direct drive!

If you read the thread starter's post carefully, he's original intention is to improve the performance of his model. He was just wondering whether adjustment of thrust angle would help. Having answered him that it has nothing to do with it, we should address his original intention of improving his model's performance, and not hog around the issue of thrust angle anymore, isn't it?

I can go around elaborating the use of changing thrust angles to improve the handling of the aircraft, but since it will be not much of the use here, I don't see the need.

Anyway, all these are just for your reading pleasure. Thrash them if you don't need them. Anyway, have fun, all of you!

[Raven]

I understand where you are coming from, but I am a little too conservative to generalise things like this. For example, Mave quoted a motor at 800Kv, which sounds pretty low, comparing the smaller motors we used. However, the motor is designed for upto 12S, which the free load rpm can spin up to around 40000+RPM! At this speed, even a prop with smallest pitch in the market will turn the model into a speed monster on direct drive!

If you read the thread starter's post carefully, he's original intention is to improve the performance of his model. He was just wondering whether adjustment of thrust angle would help. Having answered him that it has nothing to do with it, we should address his original intention of improving his model's performance, and not hog around the issue of thrust angle anymore, isn't it?

I can go around elaborating the use of changing thrust angles to improve the handling of the aircraft, but since it will be not much of the use here, I don't see the need.

Anyway, all these are just for your reading pleasure. Thrash them if you don't need them. Anyway, have fun, all of you!

Agree with Joe....

Thats why in the previous post I ask for some info. Dont wanna jump the gun w/o any necessary information. Now, back to his question...

Emm..mm... some info missing:

- You got a 1100kv motor, what is the maximum cell count it can take?
- How many watts is your motor rated?
-What is your current setup on your plane... motor(Watts and kv and max cell), esc(amps and burst amps), batt(mah and cells)

Rgds
Raven

[fudge2k85]

Yes, Charles, indeed. However, we need not to be rocket scientist here and most of the time, we are just re-inventing the wheels. Only sadly some do not understand what the wheels look like. All these theories we apply are just something we learnt in our high schools, JCs and Polytechnics! But of course, putting them in practical use is another story.

Anyway, there aren't many folks who would really enjoy engaging this hobby alone without any friends. It'll at most take me an hour or so flying alone at the slope before I head home. It is simply too boring to do this hobby alone without kicking each other's backside!

Yeah, bro. Practical is so much more difficult than theory.

Haha, yes, the best part of this hobby is more the company while flying rather than just flying alone.

[fudge2k85]

Have we confused the threadstarter already ?

If not, I am already confused with all the technical talkings...

This week is reserved for calculation up to 21 KV only. Anything more is "pok" lah...

Huat Ah ! Bun Luck !

lol!! Aiyah, I count in doubles (tai) one lei.... lol....

[viper1990]

I understand where you are coming from, but I am a little too conservative to generalise things like this. For example, Mave quoted a motor at 800Kv, which sounds pretty low, comparing the smaller motors we used. However, the motor is designed for upto 12S, which the free load rpm can spin up to around 40000+RPM! At this speed, even a prop with smallest pitch in the market will turn the model into a speed monster on direct drive!

If you read the thread starter's post carefully, he's original intention is to improve the performance of his model. He was just wondering whether adjustment of thrust angle would help. Having answered him that it has nothing to do with it, we should address his original intention of improving his model's performance, and not hog around the issue of thrust angle anymore, isn't it?

I can go around elaborating the use of changing thrust angles to improve the handling of the aircraft, but since it will be not much of the use here, I don't see the need.

Anyway, all these are just for your reading pleasure. Thrash them if you don't need them. Anyway, have fun, all of you!

Ah... yes of course.Pardon me for having tunnel vision! Of course after solving the thrust angle problem, have to move on to other factors to tune the plane's to it's optimum performance.

After all i wouldn't be able to scratchbuild and finetune my planes if i didn't read all your posts in daddyhobby for past 3 years. I took every single word you wrote into account.

[fudge2k85]

I understand where you are coming from, but I am a little too conservative to generalise things like this. For example, Mave quoted a motor at 800Kv, which sounds pretty low, comparing the smaller motors we used. However, the motor is designed for upto 12S, which the free load rpm can spin up to around 40000+RPM! At this speed, even a prop with smallest pitch in the market will turn the model into a speed monster on direct drive!

If you read the thread starter's post carefully, he's original intention is to improve the performance of his model. He was just wondering whether adjustment of thrust angle would help. Having answered him that it has nothing to do with it, we should address his original intention of improving his model's performance, and not hog around the issue of thrust angle anymore, isn't it?

I can go around elaborating the use of changing thrust angles to improve the handling of the aircraft, but since it will be not much of the use here, I don't see the need.

Anyway, all these are just for your reading pleasure. Thrash them if you don't need them. Anyway, have fun, all of you!

bro, no matter what your advice is, for a newbie builder like me, anything is worth its weight in gold (platinum even! lol).

So let me get some issues straight first before moving on... Thrust angle is more for handling rather than speed or power for the aircraft. Thus, for my current setup, i'd need a new motor and not the current one i have due to its low kv right?

[Raven]

I shall shut up since i asked twice and get no answers

[fudge2k85]

I shall shut up since i asked twice and get no answers

Shoot!!! Bro, thought I posted up liao!! Apparently it didnt came up.... Sorry sorry sorry!!!

Maximum cell count: 3 cell LiPo
Watts is your motor rated:
Current setup: 1100 kv, 3 cell 2200mAh 20C LiPo, 25A ESC...

By right should be enough le....

[fudge2k85]

Oops... sorry.... forgot to add rated power... should be around 200W i would say...

[Raven]

Shoot!!! Bro, thought I posted up liao!! Apparently it didnt came up.... Sorry sorry sorry!!!

Maximum cell count: 3 cell LiPo
Watts is your motor rated:
Current setup: 1100 kv, 3 cell 2200mAh 20C LiPo, 25A ESC...

By right should be enough le....

Argg... you are pretty much in a fixed!!
The motor is out as you cannot increase its rpm by adding more cells.
Esc is topped at 25amps and you had a 3cell 2200mah batt.
After searching through a few shops. I came to a conclusion that this will be one of the more cost effective changes you can make to your plane.

http://www.jethobby.com.sg/cgi-bin/ezsite/prod/manager.cgi?action=show&pid=2164&cid=134&idx=1&gid=12

EMP Outrunner BL Motor N2826/08 1900KV
EMP N Series Motor
Include Spare shaft & Back Mount Prop Adater.
Click to view shopping cart Add this to shopping cart
Specifications:

* Model: EMP N2826/08 1900KV
* Kv: 1900rpm/v
* No-load Current: 0.9A
* Shaft: 3.17mm
* Size : Φ28 x L28mm
* Weight: 51g
* Rated Power: 280w
* ESC: 25A
* Lipo : 2-3cells
* Suggested Prop:7x4-8x6@3cells
* Thrust:700g

At 51g, 280watts its a small price to pay. Moreover the ESC rating is 25amps which fits into your specs.

Your previous 1100kv motor chuns out about 12210rpm(1100kv x 11.1v). This motor gives you about 21090rmp. The figure itself may not be very significant so you got to push a little on the pitch of the prop.

You have got a 6x4 prop, this means the disk area of your prop pushing through the air is 6inches in diameter. And 4 meaning for every round the prop complete, it pushes forward 4 inches of air. I came across that APC do make 6x5.5e props. So if you were to couple the motor and prop together, you plane should perform differently.

Now the thrust angle thing. Thrust angle do not directly affect the speed of a plane.(A bad handling plane twitching all over the place with its ailerons trimmed to counter torque cannot fly to its max performance.) Thrust angle affects the handling of the plane by killing off the bad habits. Changing your equipment and parts on your plane might results in having to do some adjustment to the thrust angle. If you hold a bicycle wheel in your hand(by the axle.) You will feel that as the wheel spins, it will tend to want to twist itself.. The bigger/heavier the wheel, the stronger the force. This simulates the prop size and prop pitch. When you have a big prop, it is heavier to spin. The counter torque from the motor would want to (roll) the plane. Its call torque roll. When you have too much pitch, the air resistance will also cause the same effect... so both contribute to bad handling. At most time it also cause the plane to pitch up or down. And the answer to resolve this bad handling.... Thrust Angle it helps your plane to fly straight and true.

Hope this solve your query and problems.

Happy Chinese New Year

[blueangel]

I like your reply Raven.

Like a field service report, got 4 sub categories..

BACKGROUND.

PROBLEM.

SOLUTION.

CONCLUSION.