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Building F16 from scratch

Old 12-07-2022, 02:54 PM
  #26  
aaindthu
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Here is a picture of the second inlet design for my EDF.
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Also, Chennai is expecting a cyclone day after tomorrow.. it's already looking all gray and gloomy here, so can't do my second maiden flight anytime soon...
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Old 12-08-2022, 01:04 PM
  #27  
Don Sims
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Be safe during the cyclone and hope it flies well this time!
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Old 12-09-2022, 01:00 AM
  #28  
quorneng
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I might not make much difference but for maximum static thrust radius the leading edge of the inlet to create a bell mouth, like the EDF body has.
For maximum speed radius the inlet the other way to reduce drag.
A square edge EDF inlet is the worst in both cases. .
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Old 12-09-2022, 03:32 AM
  #29  
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Originally Posted by quorneng View Post
I might not make much difference but for maximum static thrust radius the leading edge of the inlet to create a bell mouth, like the EDF body has.
For maximum speed radius the inlet the other way to reduce drag.
A square edge EDF inlet is the worst in both cases. .
I've already sanded the inlet leading edge into the same lip shape as that of the edf lip or bell shape. I've read this on the same article that I mentioned.. But thanks a lott for the concern. Always appreciate it 😊😊🙏
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Old 12-28-2022, 09:09 AM
  #30  
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Default F16 2nd maiden flight and crash

Today the weather was good and I decided to fly my F16 for the 2nd time.
It flew well but it got caught in a tall and thorny tree.. By the time it came within my reach the plane was shredded.
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I am going to build it again from the start..

It could have flown better... Thrust was definitely not enough..or it was just enough...And it needed elevator up trim..

Next time i will address those issues!!

Last edited by aaindthu; 12-28-2022 at 12:36 PM.
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Old 12-28-2022, 03:11 PM
  #31  
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Well done on the maiden and that looks like a nice flying site.
I am not sure it is really a lack of thrust but rather too much drag resulting from high angles of attack. The exhaust from the EDF is moving fast so for best propulsive efficiency the plane needs to fly fast. In the video it looked to perform much better when it speeded up. The aerodynamics of the F16's blended body mean it can create lift at high angles of attack but when it does the drag rises dramatically so it slows right down. It twill then struggle to accelerate to regain the 'efficient' flying speed.
As it needs to be a 'fast' flyer it will pay to make all the surfaces, particularly the leading edges, aerodynamically shaped and as smooth as possible.
Provided you then let it fly fast you should find the EDF provided an adequate level of performance but let it slow down by raising the nose for too much or doing a tight turn it will rapidly slow. It then need delicate control inputs to get it to speed up again without loosing height and making "unwanted contact with the ground"!

I am not sure I would call you F16 'shredded'. If the electrics all still work I would just repair it. Getting good a foam repairs is a valuable skill. .
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Old 12-28-2022, 03:52 PM
  #32  
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Quorneg,

The sudden pitching up of the nose can be corrected by reducing the elevator throws or end points..
It was a thorny tree it got stuck.. Even if I did repair this depron plane, it would end up heavier than before.. and it is already on the heavier side.
Anyway, I have already started building my second one with the electronics salvaged from the crashed airplane..
Thanks for being with me, thanks to internet and wattflyer tooo..
I am planning to fly my second F16 with only elevon function like in a delta, to reduce the weight, and finally to increase the speed.. The elevons function will be on the aileron and no control surfaces on horizontal stabilizers.. I have seen many EDF models on YouTube that fly in this fashion..
So that's my plan...
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Old 12-28-2022, 09:07 PM
  #33  
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aaindthu
Using ailerons as elevators (ailervons?) would certainly reduce the pitch sensitivity as they would be operating much closer to the centre of pressure. Obviously reducing weight will help the thrust to weight ratio.
As the ailerons are further out than the elevators it is important that both servos produce exactly the same travel on each aileron otherwise when applying 'elevator' it will also induce a roll input.
It will be interesting to see how well it works.
I have a couple of simple 'two servo' delta EDFs but there the elevons are a long way behind the CofP so little elevator movement is required..
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Old 12-29-2022, 02:47 PM
  #34  
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I personally prefer using the rear stabs as Elevons if that is only control.

The old Phase 3 F16 only had tail elevons and that was a very good machine..... pity no longer sold !

Using ailerons as elevons - .... they will tend to act more like flaps IMHO.

OK - as per Q's posts ... yep - if that nose is up - that lifting body will increase drag dramatically .... the trick is to get the CoG set so that body is as flat to airflow as possible ...
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Old 01-09-2023, 06:02 PM
  #35  
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Hi all! I have a message. As much as I like to build RC airplanes, at the end of the day, it's just a hobby. I have applied for a job, a real job... for which the exam falls on 16th February.. So I am going to devote all my time to prepare for this exam. Which means I won't be able to make RC planes till February 16th.☹️

Thanks for being with me. I will continue the build after February 16th.
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Old 01-10-2023, 01:34 PM
  #36  
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Best of luck on getting the job!
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Old 01-10-2023, 03:18 PM
  #37  
aaindthu
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Originally Posted by Don Sims View Post
Best of luck on getting the job!
Thanks!! ☺
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