RC India

One of the best VPP flights/videos I have seen so far.

http://www.youtube.com/watch?v=fhCOHF24kRc

 (:|~   (:|~   (:|~

Since you have started a VPP thread, let me also take advantage of this. 

Someone please post some plans of planes that are capable of 4d and should under 350gms of AUW!

I have a 150W VPP setup, and i can pull 500gms but want to keep the plane light for inverted hovers!

I have zeroed in on a Morback 4d but it has a mid mounted prop.

Looking for something like the Nasty.  And ideas on how to get the pitch changing control rod to the servo?? Should it come through the depron fuse? 

Chan

Hi guys,

Started on the VPP setup.  Should be maidened this Sunday (hopefully)!! Bought a Katana from Mr. Sai yesterday. 

Kit was of amazing quality and the build was relatively simple.  I use 5 min epoxy instead of Foam safe cyano so my build was a bit slow.  But now I have the motor mounted and the pitch control servo installed.  So the main portion is over.

Then I attached a Watt meter to the setup and ran the motor.  Adjusted the pitch servo direction and the motor wires so that it was spinning fine. 

Then I had to program the Tx to setup proper pitch and throttle curves.  Finally when I was done, I ran the setup!! Clocked about 140 to 150 W on a 3 cell Lipo. 

Was getting very good thrust both in reverse as well as the forward direction.  The Tx was programmed in 2 modes, Normal and Stunt.  In normal mode, the throttle response is linear (like all other planes) and pitch is fixed at constant for only forward movement.  So I can fly it like any other foamy.

Once in the air I can switch over to Stunt Mode!! This is when the plane comes alive.  Throttle becomes zero in the middle position.  And when I advance throttle from neutral, the plane travels forward and when I reduce throttle from neutral it is pushed backwards  ;D!! ;D!!

And the estimated AUW of the Katana with my setup and a 1350 mAh 3s Lipo is 450g. 

The setup is as follows,

1. Airframe - Techone Katana from RC For All

2. Motor - Hyperion 2209 with VPP from http://www.aircraft-world.com

3. ESC - 30A DY Brushless ESC from RC for All

4. Battery Pack -11.1V 1350 mAh DY Lipo from RC  For All

5. Servos - 1 x 9g Turborix servo for the pitch, 1 x 9g Turborix servo for the rudder, 2 x 9g GWS servos for the ailerons and 1 x 9g servo for the elevator

6. Control Rods and Reinforcements provided in the kit (Also anyone buying this kit get a spare carbon fiber strip from Mr. Sai as it would be need while strengthening the Elevator stab).  Landing gear was supplied with the kit and looks robust.  It even has a tail wheel  :)!!

Posting some build pics below.. Would post more pics as I progress!!

- Chan

Some more pics!!

more pics!

- Chan

Great Video Anwar, It's Awesome!

MEROG

Guys,

I am now faced with a particular problem.  I have to place all the electronics inside and I have already used up most of the space for the Pitch servo.  Now in order to balance the plane, I have to have the battery way back.  Please let me know if I can use an adapter to connect the battery to the ESC as the battery's leads would not reach it from that distance.  I was thinking of making a cable with a male deans at one end and a female deans at the other end.  Should that be fine?? Or would I have a major power drop??  Moreover, I think I would be cutting part of the foam in order to accomodate the pack inside the fuse at the rear end (profile part) instead of letting it stuck on the side!  I will not have a problem with Rx placement.  ESC is already secure and the pitch servo is also secure as seen in the pics.  Let me know if there are any more parameters I should consider. 

- Chan

I dont think having a battery extension should be a major problem.
Only make sure of the structural integrity of the fuse when you cut the foam as the plane is already a light plane.
sai

Thanks uncle.  Even I was worried about that and was waiting for someone to point it out to me because I was not very sure whether it would harm the integrity of the frame as the battery pack would be an exact fit!  But let me also check any other alternative! But planning on a Sunday maiden as I would be without a Tx for the next week!

- Chan

And uncle (I know that I am making you look old here  ;D  ;D).. do you happen to stock that gauge of wire for the battery extension?

Thanks god it is just 1 generation up that u are using  8-)

I have battery extension wires.
sai

nice video and superb looking plane, please post a video when you take it for median


 :)

sahil

can v use the tail rotor setup from a belt driven heli to achieve variable pitch for such a plane?

Yep, it can be done, and seems like there are many references on the other forums. 

Here is a sample one : http://www.rcuniverse.com/forum/m_2919550/tm.htm

And one more really interesting VPP video.

http://www.vimeo.com/4681442

Hi Guys,

Had a stripped aileron servo last Saturday night when testing the controls :(.  Hence no maiden last Sunday.  Yesterday night, I sat and replaced the servos and also the original pushrods that came with the kit with better quality Thunder Tiger hardware.  The original pushrods is actually a combination of carbon fiber rod and metal rods.  We should fuse two metal wires on either side of a CF rod using a heat shrink (all included in the kit).  Now L bends should be made on either side and fixed on the servo arms and the control horns.  But this does not give room for adjustment if we get the lenght wrong.  So I replaced everything with light weight wire push rods with clevices at both ends from my Thunder Tiger Christen Eagle.  I also replaced the aileron servo.  In order to keep both the aileron servos matched, I pulled out a similar servo from the elevator and put it on one aileron and put in a 9 gm BB GWS Nano servo for the elevator to handle more torque!!  So good enough!!

I have also changed to a Futaba 2.4Ghz Rx and had a tough time programming it all over again compared to the much easier setup process in my DX6i!!  But finally got it all set and ready for a maiden.  Cant wait till Saturday. 

As already mentioned in Pramod's thread, I have also ordered a 850 mAh 3s Lipo and it should arrive probably by Saturday.  So I should be able to maiden then hopefully!!

Would definitely get some good videos from the field.  I think this is the first time somebody is trying VPP setups here in Chennai!!

- Chan

Hi ,
I have been looking at this seriously and sure  feel it is possible .
1) The tail rotor assembly of Belt driven Helis  should be available  , wondering if the top rotor assembly of Coaxial helis can be used  ???
2) Blades again are locally available
3) Did some looking around for the  tubes for the hollow shaft and am told  capillary tubes used in instrumentation could be a subs .
4) Carbon fiber or piano wire are available with me.

Thought I will just voice it here to  get some ideas on this.

sai

Ismail ,
Any Idea where capillary tubes of 3 mm OD and  around 1.5 + mm ID can be got in Chennai ?

I have seen those Excellence Carbon Fiber Tail Rotors that Aravind stocks.  They are exactly similar to my VPP blades.  And the tail rotors of a Raptor should also be fine.  They also operate on the very same principle.  If you want to do away with hollow shafts, for a better way to change pitch, check out the Mamo UpsideDown VPP system.  They are adaptable to any motor and they do not need a hollow shaft.  This is much more easier to setup and also make!

I would also be interested in making a VPP setup on a slightly smaller motor which can run on a 2 cell so that I can make my Katana loads lighter.

Or also putting a VPP system on planes like my Seduction also makes sense!! It should be literally awesome to see a big plane just flip around mid flight!!

I even saw a video of a huge 100cc gasser being hovered nose down.  They had used a VPP system on a DA 100 engine  :o :o!!

- Chan

Check the steel maket at Lingi chetty street (parrys). You get most of the diameters and have a choice of either stainless steel (SS), copper or Alum. You probably need SS for this purpose. Or if you want to make one for your specification.. then just buy a solid SS rod and get it to a lathe shop. They will do it for a modest fee.

Anything related to engines.... you will definitely find make shift parts from Lingi chetty street or walltax road...

-Ismail

hello sai uncle
do you think the tail rotor assembly will be enough to handle a 2820 motor and also dont you think the tail rotor blades would be small for this motor

i think i will be using these
http://aircraft-world.com/shopexd.asp?id=3809 (http://aircraft-world.com/shopexd.asp?id=3809)
or
http://www.r2hobbies.com/proddetail.php?prod=rcps81509 (http://www.r2hobbies.com/proddetail.php?prod=rcps81509)
this system.

the sytem is fine and the only doubt i have is that do you have single seperate rotors according to the size of the motor that is 2820 (with 2.5 kg thrust).

hey chan heard that you maidened it today how was it

Hi everyone,

Fulfilled my dream of flying a VPP plane today morning.  Went to the field a little late and found it to be quite windy.  Thought for a while and decided to go ahead with the maiden.  Assembled everything and tested it a few times on the ground.  The battery used was a 11.1V 3s 1350 mAh pack since that was the smallest I had and my 850 mAh pack is yet to arrive!  Took some videos of running the plane on the ground and then came the flight.  Mr. Meenakshi maidened the plane and I hand launched it as the wind was pretty stiff and ROG was becoming difficult! 

It tracked dead straight!! Not even one notch of trim required.. Got the Tx  from Mr. Meenakshi and started testing the plane.  The very first thing I noticed was a dramatic lack of power!! At full throttle I was just about to keep that plane up!!  Still undettered, I pulled the switch and put it on VPP mode.  Tried reversing the pitch to negative and it was slowing down fast but still not snapping into a turn. 

Put it on an inverted hover (nose down) and still not enough power to hold it.  The plane slowed down and was struggling to hold itself and it almost succeeded!! Well almost!! But the winds and the plane weight were high and hence it was not possible. 

I might have to rethink the setup and put it on a 200gm foamy.  My present setup weights about 450 gms!!  That is too heavy...

So I am removing the VPP setup from the Katana and would be putting it onto a smaller plane like the Piaget!! 

The Katana would now take a Dualsky 175W motor or a DY 2212-13 motor on a 10x4.7 prop with a 3s Lipo (1350 mAh or 850 mAh).  That should make it rock!!

Thanks for following this thread.  Would start updating once I start my new VPP plane.

Flight Video

http://www.youtube.com/watch?v=88yMkZ4jCM0

- Chan

Guys,

You tube has still not approved my video.  Please check in another 10 mins.

- Chan

hey Chan the youtube video is under processing and not yet live. i would like to suggest you to use it on a extra 300 foamy make it out of Dave powers plans and it is just about 50gm or less so it would be one heck of a plane with the VPP system on it. by then i think you will have the battery too. Any way great attempt

hey guys good news the video is up

come on why does it take long to buffer well i am even using video accelarator

Awesome plane chan bhaiya it looks awesome!!!!!!!!!!!!!!!! if the wind would have been less i think it would have been better i could hear the wind in the video

before you remove the vpp setup try it with the new battery and less wind and tell us how it worked please :) :) :)

a video of the same would be much much much appreciated  (:|~ (:|~ (:|~ (:|~ (:|~

Hi Subramani,

I dont think another 40 gm difference in weight would really improve the performance.  So it is better that I change the setup and put this on a much lighter plane.

- Chan

hey why dont you try the 2826 it too has a 5mm shaft i know i am asking for too much. just a thought 8-)

I might try that!! But weight of the motor might be too much for the plane!

I am going to put a 2217 motor on it most probably.  Looking for 200W per 500 gms!! So i need about 175W.  I have decided on the Dualsky 175W motor or the 2217.  I personally feel that the 2212-13 might be a bit too small for it!! Let me get another video for you guys tomorrow!

- Chan

good choice that would be best as 2826 might bee very heavy you are right {:)}

Hi ,
There was another katana maiden today as well at the other end of Chennai .
Dont have any pics or VDO as I forgot to take the camera  :) :)

The same tech one Katana  was maidened today  with the following set up :

1) Turborix 1300 rpm/v Motor
2) RCFORALL DY 20 A esc
3) GWS 0947 prop with Prop saver

I tried  with three diff batteries :
11.1V 3 S 1350 mah
              1000 mah
                850 mah

The best performance was with 850 mah

Chan the performance of this plane dramatically improves with a lighter wing loading .

This plane did  harriers , Rolls , inverted harriers , Loops ,Cuban 8 , stall turn , immelmen  you name it it was done today including 3 D  but the only issue with 3 D was  could not hold .
Mind you all this was acheived with  a 21 gms 1300 motor .

So I would say I will not go with anything more than a 50 gms motor  at the outer limit .
The recommended motor is a 2208  so any set up in excess of 50 gms would be counter productive as per me.
rgds
sai


Sai

hey chan bhaiya this is a 47 gms motor with a good KV it is - 2212/6 and i have used it in my f22 with custom ducting. only problem i find is that do you have a 3mm hollow shaft and other than that i think it it could be helpful

hey just calculated it gives 10.8*22(peak amp) = 237.6 W that might be good enough i believe

hi Chan bhaiya i think the above recommendation might work your planes weight comes to around
506 gms i just calculated

all weights are in gms

260                           (katana body without motor)
80                             (Battery well i calculated for 1000 mah 3s lipo might be lesser for 850 mah)
24                             ( 4 6gms servo each for rudder pitch elevator and ailerons)
47                             (2212/6 motor)
25                             (esc)
20                             (Rx)
50                             (something i missed out and push rods and extension cables,etc)

Total = 506gms of your fully loaded plane

and as i suggested it gives 237.6 W

and from lesson about how to calculate motor you said

175 to 200 W per 500 gm for a 3d plane as its 4d i think the extra 37.6 W would do the job

awaiting your reply

correct me if i am wrong

just want to help and see that thing fly and do a inverted hover  ;D ;D ;D

And one lesson I learnt is that we have to record the interesting bits of action with the aircraft being close to you !  For a hover move, please ensure the ground (or horizon) is also visible in the video frame, so that we can fully appreciate the move !

Please pass this on to who ever is manning the camera when you shoot this.  We are all eager to see this in action  :)

Hi Guys...

Today.. I put in a 2217/06 motor spinning a 10x4.7 onto the Katana.  It is a 200+W motor and 70gms.  Hell it was heavy but the performance was PHENOMENAL!! Take off was at quarter throttle.. Hovers were at less than half throttle.. Got a video but no ground perspective except in some frames.  Was doing pretty low hovers and piloting the plane towards me on these hovers!! But at one particular hover, the ESC cutoff.. A low level hover + ESC Reset + Tarmac Kissing = TOTALLED PLANE!!! Had a ESC cutoff and the plane came down pretty heavy for about 5 to 6 feet and the nose was totally smashed!!  And it was also very windy!! I pushed limits today!! Check out the video!!

http://www.youtube.com/watch?v=CR4AHyhUr-4

Hi Subramanian,

The 2212-06 motor is more suited for pusher jets and it is a high rpm motor.  This means that you would generate the watts required but the prop that it can take is very small.  I cannot spin a 10" prop on that and 3D requires spinning huge props at low rpm!! The 2212-13 is more suited for this kind of flying!!

And I think you have grossly miscalculated the planes weight!  The Katana with the VPP setup and a 1350 mAh 3s Lipo with all the works built in weighed 450 gms!!  With the 2217, I must have reduced another 20 gms!  So 200+W on a 400gm plane is rock solid power!!

Thanks for the suggestions though!!

- Chan

Hi Chan ,
Looked at the VDO  just adding my 2 penny bit here . I think the very high nose loading that could be the cause .
As I have mentioned earlier anything more than a a 50 gms motor stuck up there could be the cause of the sudden dip on the ESC reset. especially considering the plane seems to have been just getting into head wind when it went down.

The Katana this side of town flew great with the under powered set up , we were able to achieve  around 30 + secs of prop hang  at height of around 10-15 ft from the ground , but  rolls at around 5-6 ft height were possible today despite strong winds .

Sai

Yeah uncle..definitely true..As we increase the noseweight and the wing loading, however balanced the plane is, the stall speed increases... So the plane stalls at a much higher speed than before!! And landings should always be with power or it is asking for trouble!!  In my case, if I had altitude, I could have dived to gain airspeed, but here it was not possible!! And the crash was 90 deg crosswind!! The wind was 90 cross on the runway and the plane was parallel when it crashed! Next would be EPP on my part to keep the weight low and use the VPP again!

- Chan