Alex H.

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My first fixedWing plane
« on: March 16, 2019, 09:36:36 am »
Hello there,

One year ago I started researching about LibrePilot and how to build my own plane (fixedWing).
After watching a lot of videos on YouTube, I decided it's time to start from somewhere.
As majority of fixedWings are made out of different types of Styrofoam, I decided to buy some
extruded Styrofoam(I hope that extruded is the correct name) and to build my own foam cutter.

Downloaded a Wing templates, inside and outside of the Wing. I printed the template on a A4 paper.
By gluing the paper template on a piece of Plywood and cutting the Plywood with a hobby moto-saw,
I was able to make the hard temples for inside and outside of the Wing.


This is the final result.



Below you can see the other parts that I will use for my plane:

 - Camera sender and receiver:


 - 6CH 2.4GHz Receiver:


 - 2 x micro Servo 9g:


 - I don't know how this component is called, these will be glued to the Aileron:


 - Wire for connecting the Servo with the Aileron:


 - GPS module:


 - ESC 30A:

 
 - Motor A2212 / 13T | 1000KV


 - Propeller 10 x 4.5 (I think these are in inch)


 - cc3d board


 - Wood to make the wings stronger
 - Cover Film that will make the plane stronger

Next is to assemble all together and to buy some battery based on TheOtherCliff hints.
Hoping that my researches in the last year were OK, this should fly...  :)

Best Regards,
Alex

PS: I don't know to make the pictures smaller from the forum interface...
PSS: I changed the size from the source, it's better now.
« Last Edit: March 16, 2019, 09:44:58 am by Alex H. »
Best Regards,
Alex H.

Re: My first fixedWing plane
« Reply #1 on: March 16, 2019, 06:06:46 pm »
Quote
I don't know how this component is called, these will be glued to the Aileron
"Control horn" and they are screwed together with a matching plate with the aileron/elevator/rudder (elevon for you) sandwiched in between.  You can certainly add glue if you like.  :)

Quote
PS: I don't know to make the pictures smaller from the forum interface...
PSS: I changed the size from the source, it's better now.
The forum basically only knows icon and full sized.  Be aware that instead of linking to an external picture you can upload the picture and make it part of the post and it will automatically be shown as an icon at the bottom of the post and can even be inserted full sized where you want it in the post.

Ultralight experience will help a lot, but the thing that gets real pilots in trouble when they fly models is the control reversal.  When flying toward you, left is right and right is left.

<bragging but all true>
I have a Phantom ultralight that I haven't flown in years now.  I have a BRS chute.  I used to say that I couldn't remember at least looping (inside) or rolling (snap roll) it or gliding it inverted on the most recent flight.  Yes, the float carb motor will stop if you do it too long or at more than idle speed, but if you are afraid of landing such an easy to fly airplane deadstick from within gliding distance of your runway, you should find another hobby.  (Google some Phantom ultralight loop videos). I've never done any outside loops (I have a pumper carb, but never installed it or an inverted fuel system) but I honestly can't count the number of inside loops I have done.  I can say that one time I did 10 consecutive inside loops while deadstick coming down from something above 5000 feet (say 1800m).  It is a great airplane and I had the rough ground handling kit on it which took ultimate load from (+9.9g, -6g) to (+9.9g, -9.9g).  I keep it to a sane (+2.0g, -1.2g) for my comfort.
</bragging but all true>
Here is a random video (not me) to show what it can do.  And readers, if you want to play like this, the Phantom is the one you want.  Bigger motor is nice but not required, and inverted fuel system if you want inverted.


Some things come to mind:

How much does it weigh?  It needs to stay under 1kg ready to fly and the lighter the better.  Figure a battery will weigh a little less than 200g.

Calculating CG (Center of Gravity) is critical to it flying correctly.  There are formulas for calculating CG of a trapezoid wing.  For a straight wing, the CG should generally be about 25% back from the leading edge.  For a swept untapered wing that must be calculated as the average of 25% back along the whole wing which is 25% back as measured half way to the wing tip.  For a swept and tapered wing (trapezoid) the averaging must also be weighted (adjusted) for the fact that the outer wing is small and doesn't count much.  A wild guess is that your wing should balance about 42% back when measured at the center.

The center ribs have an upturned trailing edge.  Tip ribs do not.  It is common to do the opposite where the trailing edges at the tip are slightly upturned (usually just accomplished with a very slight purposeful warp) as compared to the root.  Turning the tip trailing edges up (called washout) means the root will stall first.  If a tip stalls first then that wing will drop and you have lost control.  Also, that upturn is the equivalent of up elevator when you build your elevons (elevator ailerons), just be aware of that.

Hand launching a flying wing is a bit difficult, especially if you are also the pilot and a beginner.  Something like a Bixler 1 is just so much easier to hand launch.  You have a place to grab it (the fuselage under the wing) and the prop isn't going to cut you since the motor is out of the way.  Bixler 3 has landing gear if you want that, but you will need much much much larger wheels to fly it off of grass.



Powered gliders or other airplanes with lots of dihedral also make good trainers.

Built up wooden wings will usually have some warping that must be removed before flying.  Holding the wing very still and looking at it from behind the center at arm's length and sighting along the flat bottom of the wing and looking left and right, you can see if there is a warp in the wing.  I guess you used heat shrink covering.  Hold it untwisted, reheat and hold 10 seconds till cooled will allow you to unwarp the wing.  I would add "washout" where the trailing edge of each wing tip is turned up the same very small amount.

CC3D and GPS:  CC3D does not do GPS flight modes like RTL/RTB.  It only allows the GCS to plot where it is on a map and only if you have added telemetry.  CC3D does do stabilization, like levelling out when you take your hands off the transmitter.  Also, it looks like that GPS is one of the ones that does not have configuration memory and CC3D does not have the code to load the correct configuration at each power up.  Revo class FC does this automatically.  Also, it may be better to have a GPS that has a compass when you get around to doing GPS flight modes.  GPS with compass is only supported on Revo class FC, not CC3D.  DJI Naza clone GPS with compass costs about $20 on eBay; again only for Revo class FC.

There is no general set of FC settings that will work for all airplanes.  The best procedure has you adjusting the settings, starting with the most basic settings first.  That means flying the airplane without FC stabilization to start with to get warping, trim, linkages, control throw max angles all adjusted correctly before adjusting the FC in Rate mode and finally in Attitude mode.  This means flying it without stabilization, like in the old days before FCs.  :)  I would also skip the FPV camera till you have the plane flying well.  Less weight and less expensive things to break in a crash.  :(

Lastly, a story.  I was a 15 year old who wanted to teach himself how to fly.  It took me a year and many airplanes.  Your airplane can fly, but there are many things that can make it crash that all must be correct before the first flight.  The best thing you can do is to find a local model airplane club and watch for a few days, then ask the best flier if there is someone who can help you with all the things you don't know.  I also recommend that you put that airplane away for later when you know how to fly better because one crash will hurt it badly and 3 crashes (and fixes) would make it heavier and less well shaped and harder yet to fly.  These things cost money, but buying a good EPO (a type of foam) foam trainer airplane (not the shape you like, but the shape you need) will be easier to fly, survive crashes better, and be less painful when crashed.
« Last Edit: March 17, 2019, 12:53:21 am by TheOtherCliff »

Alex H.

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Re: My first fixedWing plane
« Reply #2 on: March 26, 2019, 09:26:21 am »
Update: I have reinforced the wing with some wood, glue and heat shrink covering. The heat shrink covering will be posted in a future post, as it was too late last night to make another photo.


Quote
Ultralight experience will help a lot, but the thing that gets real pilots in trouble when they fly models is the control reversal.  When flying toward you, left is right and right is left.
I already experienced this part with RC cars :)

Quote
Phantom ultralight
I have watched some videos on YouTube and it's pretty impressive, but I like something that is close to Sonex .

Quote
How much does it weigh?  It needs to stay under 1kg ready to fly and the lighter the better.  Figure a battery will weigh a little less than 200g.
I have weigh it and it was ~250g, without the reinforcement wood and cover film.

Quote
Calculating CG (Center of Gravity) is critical to it flying correctly.
Some said that it will be OK to have a nose down wing, in case engine stops so that the wing can glide down, as the opposite nose up will get stalled. For the moment I have a nose up, but with battery I will balance it to go nose down.

Quote
The center ribs have an upturned trailing edge.  Tip ribs do not.  It is common to do the opposite where the trailing edges at the tip are slightly upturned (usually just accomplished with a very slight purposeful warp) as compared to the root.  Turning the tip trailing edges up (called washout) means the root will stall first.  If a tip stalls first then that wing will drop and you have lost control.  Also, that upturn is the equivalent of up elevator when you build your elevons (elevator ailerons), just be aware of that.
Still compiling this part...

Quote
CC3D and GPS... FPV camera
Snap... I will use only CC3D, then later I will invest in another board. As for FPV I wait to have it fly, then once I master it I will put the FPV camera.

Quote
Hand launching a flying wing is a bit difficult, especially if you are also the pilot and a beginner.
As you say now... hmm didn't think about that ;D, but checking YT, I have seen some launching the wing by throwing it wing side. That will be a challenge.

Quote
I guess you used heat shrink covering.
Yes, I already covered the wing. looks OK, no warp, maybe because I have use the device from the picture (the one on the right) and I can control the heat and pressure applied. I made a mistake and melted a little bit the foam as I heated the device above 165Celcius degree (lesson learned).

Quote
buying a good EPO (a type of foam) foam trainer airplane (not the shape you like, but the shape you need) will be easier to fly
For the moment I will take the risk and use what I have build, as I for the moment I have invested some money and time in this wing.
On the other hand I have from my son some planes from EPO, pretty nice shaps I can modify them and try to make them fly, but I will have to add ailerons, elevator, rudder, small lipo, motor and servos. Maybe this will be next project.
« Last Edit: March 26, 2019, 01:51:02 pm by Alex H. »
Best Regards,
Alex H.

Re: My first fixedWing plane
« Reply #3 on: March 27, 2019, 03:12:33 am »
A new Phantom is about the price of just that motor, does not require a licence (or medical certificate) to fly, and does decent stunts.  I wasn't really pushing anyone to buy one, just saying that I understand the ultralight itch because I have an ultralight myself.   :)

Alex H.

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Re: My first fixedWing plane
« Reply #4 on: March 27, 2019, 07:24:30 am »
Quote
A new Phantom is about the price of just that motor, does not require a licence (or medical certificate) to fly, and does decent stunts.  I wasn't really pushing anyone to buy one
Far away from this. I find it nice that in US, (as I understood) there is no license require for a specific configuration, the problem is that I'm EU and here even the mosquito need a license to fly, so to say.

Quote
It is a great airplane and I had the rough ground handling kit on it which took ultimate load from (+9.9g, -6g) to (+9.9g, -9.9g).
I wanted to say that +9.9g, -9.9g ain't something for me. I remember the time when my instructor exercised with me recovery from stall, 300-400m above the ground, I was barely handle the free fall from the time it began fall until recovery. Image that all these exercises happen suddenly during the normal fly. He just said to be: "I will control the plane", then he just pulled the stick back and brought the plane in stall, then just said: "Now take control and recover".

I prefer something that has a close cockpit, can gain some speed and does no acrobatics, and if it's possible equipped with a parachute.:)
I specified Sonex, as I was watching a video a few days ago, and in 2007 had in mind to but one, as kit, but it could be any close cockpit Ultralight airplane.
Best Regards,
Alex H.

Alex H.

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Re: My first fixedWing plane
« Reply #5 on: March 27, 2019, 07:30:54 am »
Update:
I have applied the Heat shrink covering.


and I have heat glued with Elevons, using the heat shrink cover, which also sticks to the surface.


Next is to mount the motor, servos, ruders and the other components.
« Last Edit: March 27, 2019, 08:34:26 am by Alex H. »
Best Regards,
Alex H.

Re: My first fixedWing plane
« Reply #6 on: March 27, 2019, 10:36:24 pm »
At 9.9G a 100kg (220lb) man weighs about 1000kg (over a ton); as much as a small car.  He can't keep his head up since it weighs so much, and even with a military jet fighter G suit will immediately black out due to loss of blood to the brain.  :o  :)  I generally keep it to +2G/-1.2G.  That's my comfort level.  Well it's been years since I have flown it.  I have RC friends, but ultralight friends are rarer.

I prefer something that has a close cockpit, can gain some speed and does no acrobatics, and if it's possible equipped with a parachute.:)
I do understand that.  I bought it because it was strong, had a good reputation, and I could do stunts if I decided to later.  Of course, being an RC pilot for many years before that can lead to stunts... :)  ..and it has a BRS ballistic parachute.

Alex H.

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Re: My first fixedWing plane
« Reply #7 on: April 01, 2019, 07:59:57 am »
Update:
  - Motor support
      - Final state is with all 4 holes carved for nuts with Φ 3mm.


Next I will mount the motor and ESC.
Meanwhile I found to 2x2S LiPo battery from a plasticky drone I have, but I was never able to fly that thing.
I ordered some XT60 and XT90 connectors, I will use these for battery connection.
« Last Edit: April 01, 2019, 08:41:38 am by Alex H. »
Best Regards,
Alex H.

Alex H.

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Re: My first fixedWing plane
« Reply #8 on: April 03, 2019, 07:57:14 am »
Learning from mistakes...

 XT90 connector was a mistake, as it is too big for current purpose. The length is 5cm...
 Now I'm waiting for the second connector XT60.
 Something like this happens when you are a Newbie and forget to do your home  works...

Best Regards,
Alex H.

Alex H.

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Re: My first fixedWing plane
« Reply #9 on: April 03, 2019, 01:33:10 pm »
Today I received the other connector XT60.
Also I received connectors for the battery that I have and the battery Alarm-buzzer(the one recommanded by TheOtherCliff.

Now I will have to solder the two red connectors with XT60 and the other part of the XT60 connect will go to the ESC.
The only problem is now to find out which side of XT60 connector goes where. (the female to the battery and male to ESC or vice-versa?)
The battery will be enough for testing purpose, to check the motor rotation direction, to check the servos action, etc...




« Last Edit: April 03, 2019, 01:41:00 pm by Alex H. »
Best Regards,
Alex H.

Re: My first fixedWing plane
« Reply #10 on: April 03, 2019, 06:43:44 pm »
Flat side of XT-60 is red is positive is +  There are usually some tiny + and - molded on the XT-60 that you can read.

The Lipo Alarms that have all those pins are supposed to plug straight into the balance connector (3 pin connector when you have 2 cell Lipos) of the battery (or into an extension cable that has all those wires).  That way the alarm can see each individual cell voltage and alarm if any one cell is too low.  Watching individual cells is the best feature of that alarm.  Look on the back side of the alarm for the (-) and plug that into the most negative of the balance connector (black wire in your case).  Use the tiny button on the alarm to set the alarm for 3.7V (that's 3.7 per cell).  You can set it to 3.6, but then you really must land as soon as the alarm goes off.

I see that you have some 2 cell Lipos.  1000KV 2212 size motor with 10x4.5 inch prop is best matched for a 3 cell Lipo.  It will only have about half power (V^2/R) and 2/3rds of air speed with a 2 cell Lipo with that prop.  It will probably have enough power to fly, but you will need to use full power most of the time and climb slowly to avoid stalling.

With that low KV motor, 10x4.5 is a low speed lifting prop, that works well for a quadcopter that does not have to high prop pitch speed to stay in the air.  An airplane needs more prop pitch speed.

In short, change your prop.  Here is why.  KV is RPM per volt.  Motor KV and prop size and number of cells in battery must be calculated together.  That battery puts out about 8 volts.  On a 1000KV motor that would be 8000 RPM without a prop.  It will be about 80% of that with a correct prop so 6400 RPM.  The prop pitch speed is the speed of the air blast.  The airplane will not go faster than that unless it is diving.  The prop is not even pulling when the airplane is at that speed.  6400 revolutions per minute times 4.5 inches is 28000 inches per minute so the air blast speed is 28000 inches per minute at full throttle.  The airplane needs to be going slower for the prop to actually be pulling.  Lets say 75% of that speed.  28000 * 75% is 21600 inches per minute. 21600/39.34 is about 550 meters per minute or 9 meters per second or only 33 KPH or 20 MPH at full throttle in a shallow climb.

Because of prop pitch speed (for that motor KV, battery, and prop) it will only fly that fast at full throttle.  You probably want to change one of these.  The best is to go with 3 cell battery instead of 2 cell, but that is wasteful for the batteries you have bought.  Next best is to change the prop.  10x4.5 (or 9x6) is matched to the motor at 3 cells and gives maximum power.  For 3 cell, you don't want a bigger prop because it will overheat the motor and you don't want a smaller prop because you will get less thrust for no reason.  For a 2 cell Lipo you need a bigger prop since it is spinning slower.

I am going to make some guesses at better props for this aircraft with this motor.  I would guess a 3 cell Lipo with a 9x6 prop or a 2 cell Lipo with a 10x6 (or 9x8) prop as a place to start.  After flying what you have, you could consider using both batteries at the same time, in series to effect a 4 cell Lipo.  That is probably slightly out of spec for the motor and ESC, so you must decide if you want to take the risk, but my guess is that they would work.  You MUST use a smaller prop for this 4 cell setup, say an 8x5.

With a 2 cell Lipo, you will need to use full power because of pitch speed.  With a 3 cell, you will have better performance.  With 4 cell it will be fast and more powerful yet.

Balance your prop!
« Last Edit: April 03, 2019, 06:59:44 pm by TheOtherCliff »

Alex H.

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Re: My first fixedWing plane
« Reply #11 on: April 03, 2019, 07:04:03 pm »
Quote
Flat side of XT-60 is red is positive is +  There are usually some tiny + and - molded on the XT-60 that you can read.
I have seen that while soldering. I was wondering how to place these female and male XT60 connector, meanwhile I checked YT and found out that the male connector was placed on the ESC and the female connector on the battery side.

Quote
The Lipo Alarms that have all those pins
I found it on the back, as you said + there is a button opposite to these pins used to start setting mode.

Quote
I see that you have some 2 cell Lipos.
Only for testing purpose, such as powering up the receiver,motor direction rotation, CC3D board, checking the servos...
I found out that one server is broken, as it is making a continuous noise.
I will have to invest in some 3cell Lipos and a charger as the construction project is coming to an end and the fly test will start.

Quote
In short, change your prop.
I will keep the current prop for the moment, as the 3 cell Lipos will come soon.

And here is the final result after soldering the connectors.
« Last Edit: April 03, 2019, 07:29:56 pm by Alex H. »
Best Regards,
Alex H.

Alex H.

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Re: My first fixedWing plane
« Reply #12 on: April 07, 2019, 05:50:49 pm »
   Meanwhile, I visited some local RC flight Club. They told me that it will be good if I play with an RC Flight Simulator, before fly my plane.
I bought from eBay a Remote Control Mode 2 with an USB connection, the price was 3Euro, as it was a little bit defect. The Yaw Stick was not centered once it was moved left or right, but with a little bit of Universal Silicon Oil, everything became smooth. Opening the Controller, i have noticed that there is place for some other buttons. Latter maybe I will check if the Controller firmware will send information from these connections also.

Now I'm training my self with PicaSim, it has a wide range of planes and sceneries. It's ok for me, because as TheOtherClip said, pilot experience helps, but RC fly from outside the plane is different.

Best Regards,
Alex H.

Alex H.

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Re: My first fixedWing plane
« Reply #13 on: April 08, 2019, 08:09:34 am »
I manage to configure the CC3D board together with FS-iA6B receiver and an FlySky transmitter. The servos are acting accordingly, the motor is spinning in the right direction as shown in the GCS setup wizard. I don't know if the propeller has the right direction, but the good thing is that the motor came with 2 propellers for the two spinning directions :D.

Final result for the motor support, but the glue I have used is useless, as the nuts are coming out... I must check another type of bonding glue that doesn't affect the Styrofoam.

« Last Edit: April 08, 2019, 09:37:16 am by Alex H. »
Best Regards,
Alex H.

Re: My first fixedWing plane
« Reply #14 on: April 08, 2019, 06:10:31 pm »
If you didn't know:
- Putting a prop on backwards does NOT make it blow backwards, it just makes it way less efficient.
- The small raised prop size numbers molded into the prop always go toward the front of the airplane.  For a pusher airplane, that means mounting the prop backwards.
- The standard prop / motor direction is counter clockwise when viewed from the front of the motor (as if it were mounted on front on a normal airplane).
- If you want standard props to work in the future you should make the motor direction backwards (make it clockwise when viewed from the front of the motor).  That is easy to do.  If it is wrong, just swap any 2 of the 3 wires that go from ESC to motor.

So, use the normal prop (CCW counter clockwise prop) mounted backwards and make the motor spin CW clockwise.