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



      

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  !! !!

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    ).. do you happen to stock that gauge of wire for the battery extension?

Quote from: chanvivek on May 22, 2009, 05:55:44 PM
And uncle (I know that I am making you look old here    ).. 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 

I have battery extension wires.
sai

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

QuoteThanks god it is just 1 generation up that u are using   

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.

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

Quote from: anwar on May 23, 2009, 02:07:31 PM
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

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  !!

- Chan

Quote from: rcforall on May 27, 2009, 06:03:55 PM

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

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
or
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



- 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