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Nov 30, 2017, 11:10 AM
IMO ( In My Opinion ) →
balsa or carbon's Avatar
Quote:
Originally Posted by batata003

@balsa or carbon as I promised yesterday I used the motor you gave me (same you used in the nutball) and built a small beagle + ezfly + something else plane! See it here -> https://www.rcgroups.com/forums/show...4#post38722345

I took care of the wires and glued then to the axis of the motor and it worked great, it will last forever! I really enjoyed playing with this small plane, much easier to build, not much dust in my room and cheap! Also it flies slowly which I love! What did you think of it?
If you want that plane to fly more smoothly ( less rocking back & forth ) , it needs a longer tail moment . To get a longer tail moment , make the tail longer so the horizontal stabilizer/elevator and vertical stabilizer/rudder are further away from the wing . You will probably also need to extend the nose so you can move the battery forward .

The rocking back & forth is called dutch roll , and that is a common problem with the FliteTest Old Fogey , which has a short tail moment . When I made my Old Fogeys , I made them with a longer tail moment .... and a larger vertical stabilizer also helps .
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Nov 30, 2017, 11:31 AM
IMO ( In My Opinion ) →
balsa or carbon's Avatar
Quote:
Originally Posted by batata003
@balsa or carbon actually the hardest thing to make was to transform this small motor into a pushed cause when I inverted the prop the prop adapter couldnt get inside the other side of the prop. So I had to drill a hole to make the prop hole larger. But now I am seeing a problem: the rubber band is touching the sharp edge of the prop, do you think it might cut itself in the air?

One more thing: this rubber band looks a little dry, do you know if there is any home product that I can use in the rubber band to hidrate it?
Unfortunately the rubber bands don't last very long and need to be replaced with a fresh rubber band every now and then . You can get them at a plumbing supply store ( O-rings ) , or use the small rubber bands that women/girls use on their hair . I haven't tried it yet , but a lot of people are using something called Thera-Band latex tubes ..... you just slice a ring off the tube for what you need .

You can try putting a piece of paper or cardboard between the sharp edge of the prop and the rubber band .
I always use at least two bands , incase one breaks while flying in the air .
Nov 30, 2017, 12:45 PM
Registered User
Extreme Sports's Avatar
Gil, the trick with the rubber o-rings is to never leave them on the plane when you are not flying. They perish and break within a few days in some cases. Take them off and they last much, much longer. It might help to store them in glycerin, but it's really not worth the effort IMHO. New ones should be available from hardware stores or bearing suppliers.

Theraband is hard to find outside of the US, but can be left on the plane for much longer. But even it deteriorates over time if left 'in tension'. Small rubber bands can also be used, but suffer the same problem.

So whatever you use, take the prop and the band off each time you finish flying.
Dec 07, 2017, 12:32 PM
Potato003
@balsa or carbon thanks for advising me on increasing tail distance from the wing and its size! I will keep that in mind on my next build! When my planes dont work well I am just adding a strip with 1 to 2m long to the tail and they stop being "pitch sensitive". But it generates lots of drag so your approach is much better!

Also I liked you suggestion of buying a tube! I found a guy who sells o-rings but his price is crazy so I will check a thick tube at a close plumbing store and cuting a part of it is a great idea! Dont need to join parts, just cut and use the cutted part as the ring! I also liked your idea of using a cardboard to avoid damaging the ring, I will do that right now!

@Extreme Sports wow I was leaving my o-ring in the plane all the time! I just removed them right now and will remember to only put them when I am gonna use, makes lot of sense. I tried finding Theraband but had no luck here in brazil, but the @balsa or carbon suggestion of a tube I think will be cheap and I will be able to use!

My friends, I am trying to come up with the most efficient plane I can (using a mix of ezfly + beagle) so after learning many things with you I still have 2 important questions that I cant find answer:

1) when I have the horiontal stabilizer at the tail, do I really need it? Cant I just use the elevator attached to a spar? Please see the 2 tails in the image I attached. I always read that the tail is not good for efficiency, it generated drag and if the horizontal stabilizer is not well parallel with the main wing it will reduce efficiency. Why people just dont use a spar at the tail and attach the elevator to it? Why people dont do this?

2) do you have any link/video that demonstrates the amount of lift that a Kfm airfoil generates? Sometimes I spend so much time doing the wing airfoil profile right and I have no idea if it contributes 10% to the lift of 50%! For example: a flat profile wing (with exactly the same width in all the chord and wingspan) will be how many times more innefficient than a proper airfoil (most of the time I use the KFm-2). Is there any empyrical data of experiments that shows that a proper airfoil is N times better than no airfoil?
Dec 07, 2017, 01:34 PM
IMO ( In My Opinion ) →
balsa or carbon's Avatar
Quote:
Originally Posted by batata003
1) when I have the horiontal stabilizer at the tail, do I really need it? Cant I just use the elevator attached to a spar? Please see the 2 tails in the image I attached. I always read that the tail is not good for efficiency, it generated drag and if the horizontal stabilizer is not well parallel with the main wing it will reduce efficiency. Why people just dont use a spar at the tail and attach the elevator to it? Why people dont do this?

2) do you have any link/video that demonstrates the amount of lift that a Kfm airfoil generates? Sometimes I spend so much time doing the wing airfoil profile right and I have no idea if it contributes 10% to the lift of 50%! For example: a flat profile wing (with exactly the same width in all the chord and wingspan) will be how many times more innefficient than a proper airfoil (most of the time I use the KFm-2). Is there any empyrical data of experiments that shows that a proper airfoil is N times better than no airfoil?

1) You can certainly make a full flying elevator , most commercial airliners have full flying elevators ..... usually called a stabilator .

2) In My Opinion , for slow flying planes : airfoil doesn't matter much ..... light wing loading is a much bigger factor . If the plane is meant to fly right-side-up all the time , make an asymmetrical airfoil like a KFm2 or Jedelsky airfoil . If the plane is meant to also fly inverted , then make a symmetrical airfoil .... even if it's completely flat .

IMO , for faster flying planes : a proper curved airfoil is more important for the reduced drag .... rounded leading edge and tapered trailing edge . And the same applies : if it is meant to fly right-side-up all the time , asymmetrical airfoil . If it is meant to also fly inverted , symmetrical airfoil .





This plane by John Kerbob has a stabilator , and also wingerons ( the entire wing moves as ailerons ) :


CTC Carbon Traveler Convertible (2 min 41 sec)








This plane by Donatas Pauzuolis has a completely flat symmetrical wing so it flies inverted as easily as right-side-up . It even has drag brakes so it doesn't speed up much when it's going straight down .


F3P demo in Leipzig by Donatas Pauzuolis (6 min 55 sec)








This plane ( by me ) has an asymmetrical Jedelsky airfoil wing .



FT Old Fogey-ish with 60" wingspan (1 min 56 sec)
Dec 07, 2017, 01:55 PM
An itch?. Scratch build.
eflightray's Avatar
For a bit of fun, find a cheap donor toy and scratch build something different.

The donor was a Silverlit Classic twin biplane, the scratch was a profile Beechcraft built from Depron.

It flew, but was terrible at turning, (throttle and differential motors control RC, no servos ).

But super cheap and a good laugh, (even if it didn't work out as hoped for)


.
Dec 07, 2017, 01:56 PM
pull up -- PULL UP!!!
Quote:
Originally Posted by batata003
One more thing: this rubber band looks a little dry, do you know if there is any home product that I can use in the rubber band to hidrate it?
Actually O-rings might work well, but they're kind of a pain in the ass. Sometimes hard to find, too big, too stiff, whatever.

For convenience you can actually use any handy small rubber band for these small motors. Just fold them to double or triple loop, whatever fits well.
Dec 12, 2017, 01:58 PM
Potato003
@balsa or carbon 1) I didnt know I could have a full elevator! Good news, next time I will make a plane with full elevator! 2) I am glad you said that, sometimes I spend so much time making the airfoil right and I always have that thought "is it gonna worth adding weight to make the airfoil shape?". Now that you said that the wing load is a much stronger factor in slow flyers I will not bother too much with that on my next build! I will certainly not fly upside down till I practice a lot but I liked of your advice of a symetrical airfoil in case I need to fly upside down It makes total sense.

The CTC plane you pointed has all control surfaces totally flexible! I think that most of the plane surface area is able to move and I loved that concept, it looks very efficient and saves weight!

The F3P you posted is incredible, sometiems during the video I cant know if the plane is upside down or up! The person controlling it makes it so easy!!!

Your giant 60`` plane has a weird airfoil! I read online that it's suitable to carrying big loads, I cant understand how it worked so well in your plane since you are carrying almost no load and it still flies very slowly (which I love!!!). Your plane (as the F3P) looks like it's in slow motion, I couldnt believe it! Also, nice place where you are flying, great space! I saved the Old Fogey plans from Flitetest so I can give it a try as soon as I finish my collection of "BeazFly" that I will show you in the coming days! I liked this name you created!!!! I will make a giant one (a little smaller than yours) with removable wing and I will use the big motor you sent me!!! I still didnt find courage to use that motor and I think it will be nice to use in such a plane!

Just correct me if I am wrong: one of the motors you sent me is the one you linked on your last post, right? I mean, the big motor that I mentioned in the last paragraph that I want to use is the one in the link below you told me, right:

https://produto.mercadolivre.com.br/...ner-1700kv-_JM

The other motor you said (Hextronik 16gram) where you would recommend me to use it? In small planes? Cause the 2S motor you sent me I am using it a lot, it's my favorite plane to take inside the bus and fly!

As soon as I finish my collection of Beazfly I will show you and after that I will come back to the Dart plane and the pizza box so I can try fly using aileron!

@eflightray my uncle and motor would kill me if I built such a big plane inside this apartment! The throttle differential you mentioned is what I am looking for in a plane so I dont need to use rudder (almost every crash I have the rudder is the first one to break!).

@hard line I went to a plumbing store and they didnt have the o-rigns but they had some PVC valves that contained the o-rings but they were not cheap and I could not even see the o-ring size! I think your idea is the best so far, I will go to a stationary store and look for good and thick rubber bands! @balsa or carbon already sent me lots of rings but I will try to use 2 rings everytime I fly so if one breaks the other saves. I will always use a proper o-ring (like the ones @balsa or carbon sent me) but I will also attach a rubber band (from the stationary store) so I try to avoid problems!
Dec 12, 2017, 03:05 PM
IMO ( In My Opinion ) →
balsa or carbon's Avatar
Quote:
Originally Posted by batata003

Just correct me if I am wrong: one of the motors you sent me is the one you linked on your last post, right? I mean, the big motor that I mentioned in the last paragraph that I want to use is the one in the link below you told me, right:

https://produto.mercadolivre.com.br/...ner-1700kv-_JM

The other motor you said (Hextronik 16gram) where you would recommend me to use it? In small planes? Cause the 2S motor you sent me I am using it a lot, it's my favorite plane to take inside the bus and fly!
MercadoLivre sells lots of hexTronik products , just enter "hexTronik" in the search on their website . hexTronik has motors from tiny 2 gram , 10 gram , 16 gram , 20 gram , 24 gram , all the way up 91 gram . The 24 gram motors are probably the most popular , and come in several kv choices ..... from 1300kv up to 3000kv . You have a 20 gram hexTronik motor ( the 2S motor ) , and a giant 78 gram hexTronik motor .

My favorite is the 1700kv 24 gram hexTronik motor , I use it more often than any other motor .
Dec 12, 2017, 06:24 PM
Potato003
Ahh one more thing! I dont know if I should open a new thread about this other question I am gonna make but since I already opened to many I will ask it here to avoid filling the forum with too much quetions of mine.

I am experimenting using a camera in my EzFly and I tried different positions but didnt like anyone of them! I putted some hours in adobe premiere so I could edit my 3 different camera positions to you will what is going on. I made my best to avoid taking so much of your time but any advice would be appreciated! In all the cases I felt the camera view is not right also the drag it generated was so big that I had to drive my plane most of the times using 90-100% throttle!

https://photos.app.goo.gl/Bn1E3pcpSp9sExxT2

PS: @balsa or carbon thanks for recommending that brand of motor, most people only buy EMAX here cause they are usually 1/3 the price of other brands! I am glad the 2 motors I have here are from that good brand you recommended, thank you so much! That's why I like so much the small 2s motor, it flies very well and is very battery saving!
Dec 12, 2017, 07:58 PM
IMO ( In My Opinion ) →
balsa or carbon's Avatar
Quote:
Originally Posted by batata003
In all the cases I felt the camera view is not right also the drag it generated was so big that I had to drive my plane most of the times using 90-100% throttle!
I haven't done much aerial photography , so I can't really advise you much about that .
You can probably stabilize the video by making an electronic ( gyros ) or mechanical stabilizer , I would stabilize roll for sure .... and maybe also pitch . And try to make smoother , flatter turns when flying the plane .

If the weight/drag of the camera is a problem , you can :
1) get a smaller camera
2) make a bigger plane
3) use a more powerful motor
Dec 12, 2017, 11:15 PM
pull up -- PULL UP!!!
Quote:
Originally Posted by batata003
@hard line I went to a plumbing store and they didnt have the o-rigns but they had some PVC valves that contained the o-rings but they were not cheap and I could not even see the o-ring size! I think your idea is the best so far, I will go to a stationary store and look for good and thick rubber bands! @balsa or carbon already sent me lots of rings but I will try to use 2 rings everytime I fly so if one breaks the other saves. I will always use a proper o-ring (like the ones @balsa or carbon sent me) but I will also attach a rubber band (from the stationary store) so I try to avoid problems!
Actually you don't want heavy duty thick rubber bands. Rather small to medium regular ones. Since you're going to need to double or triple loop the band to be short enough, thick ones wouldn't fit. It will be sufficiently strong just from the multiple loops. You currently seem to be in an overkill frame of mind. With a few different attempts you'll find what works best for you.
Jan 12, 2018, 02:58 PM
Potato003
@hard line thaks for your observations, they were very clear and taught me a lot

hey @balsa or carbon I had to travel some days to different places to stay with family and I had opportunity to make 3 ezfly/beagle planes and fly with them! I posted it in the link below in case you wouldnt get notification of this post -> https://www.rcgroups.com/forums/show...postcount=1559

I also liked what you said about the camera, I will go with the 2) alternative, make a bigger plane! And to do that I am trying to make it as more optimized as possible! So I started from scratch creating a new tail for my plane! I created it only using the control surfaces and nothing more to reduce drag, weight and increase maneuvability!

See pic attached and video below. If you approve I will continue the build of this plane.

https://photos.app.goo.gl/nkmxD8v3R8GJp8EJ3
Jan 12, 2018, 08:01 PM
IMO ( In My Opinion ) →
balsa or carbon's Avatar
Quote:
Originally Posted by batata003
@hard line thaks for your observations, they were very clear and taught me a lot

hey @balsa or carbon I had to travel some days to different places to stay with family and I had opportunity to make 3 ezfly/beagle planes and fly with them! I posted it in the link below in case you wouldnt get notification of this post -> https://www.rcgroups.com/forums/show...postcount=1559

I also liked what you said about the camera, I will go with the 2) alternative, make a bigger plane! And to do that I am trying to make it as more optimized as possible! So I started from scratch creating a new tail for my plane! I created it only using the control surfaces and nothing more to reduce drag, weight and increase maneuvability!

See pic attached and video below. If you approve I will continue the build of this plane.

https://photos.app.goo.gl/nkmxD8v3R8GJp8EJ3
Hey Gil ,
Your full floating rudder & elevator look OK , but they may be a strain on your servos . The pivot points look a little too tight , see if you can loosen them up . And if you put the pivot point about 1/4 to 1/3 back from the leading edge of the rudder & elevator , that will make it easier for the servos . ↓
Last edited by balsa or carbon; Jan 12, 2018 at 09:01 PM.
Jan 13, 2018, 03:36 PM
Potato003
@balsa or carbon thanks!! I will move the pivot a little further back so the servos dont have a hard time spinning the suface controls! I will continue building it right now and I will upadte you with more pics.

In case you missed, I am trying to learn how to land these types of planes on my hand! On xmas's weekend I traveled to my expected father in law house and since I didnt have space to land I had to learn to do that on my hands! If you have any suggestions I will be glad!

Natal na casa do sogro aprendendo a pousar aeromodelo na mão (2 min 16 sec)


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