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Feb 02, 2014, 05:19 PM
Registered User
Regarding the problem with nacelle servo travel:
The best way to fix that problem is to make the servo neutral at 45deg (i.e in slow forward flight mode) instead of 0deg (fast forward flight mode). The reason is, you dont need travel in the downward direction of the nacelle, so making the servo neutral at FFF position is pointless. That way, you will have tons of travel either side of SFF position.

In other words:
1. Detatch nacelle from servo
2. Set up servo to be in neutral position in SFF mode
3. Adjust other flight modes to have correct servo travel
4. Re-attach servo to nacelle
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Feb 02, 2014, 06:10 PM
3D Heli Pilot
tom stanton's Avatar
Thread OP
Quote:
Originally Posted by jolyboy
Regarding the problem with nacelle servo travel:
The best way to fix that problem is to make the servo neutral at 45deg (i.e in slow forward flight mode) instead of 0deg (fast forward flight mode). The reason is, you dont need travel in the downward direction of the nacelle, so making the servo neutral at FFF position is pointless. That way, you will have tons of travel either side of SFF position.

In other words:
1. Detatch nacelle from servo
2. Set up servo to be in neutral position in SFF mode
3. Adjust other flight modes to have correct servo travel
4. Re-attach servo to nacelle
Thanks for the advice, however, it is already setup the way you have described. The neutral is set for SFF, but it still doesn't have complete travel. I've increased the travel to 125% on my tx and the kk2 board, but the servo doesn't seem to follow. Very odd, but it not really a problem for now.
Feb 02, 2014, 10:38 PM
Registered User
Ah, good call.

I had the exact same issue you describe, wasn't getting enough travel no matter what I set up in mixes, radio etc. The solution is to modify the servo limits in the OpenAero software (if you have not tried that already). From what I recall, its a totally different section from the mixing section (or possibly right down the bottom of the mixing section) which is why I found it so difficult to achieve the right amount of servo travel also.

EDIT: After thinking a bit more, I think it's down the bottom of the openaero menu, called "positive servo travel" and "negative servo travel"
Last edited by jolyboy; Feb 03, 2014 at 01:59 AM.
Feb 20, 2014, 05:00 AM
Registered User
Hello, Tom! Glad to see you doing Osprey V22. Which mode you are using?BICOPTER? Please explain in detail under your flight control wiring.(m1 m2 m3 m4 m5 m6 m7 ) Thank you very much!
Feb 20, 2014, 05:37 AM
3D Heli Pilot
tom stanton's Avatar
Thread OP
Quote:
Originally Posted by Wanghu
Hello, Tom! Glad to see you doing Osprey V22. Which mode you are using?BICOPTER? Please explain in detail under your flight control wiring.(m1 m2 m3 m4 m5 m6 m7 ) Thank you very much!
I'm actually using Openaero VTOL firmware which allows me to setup my own mode. In a hover, it is pretty much set-up as a bicopter, but this changes as it transitions to FF. In the specifications video, I go over which output is which, but I'll explain in anyway.

M1 - Left motor (looking from the back)
M2 - Right motor
M3 - Left servo for hover control
M4 - Right servo for hover control
M5 - Left Tilt servo
M6 - Right Tilt servo
M7 - Rear elevator

Hope this makes sense
Feb 20, 2014, 10:13 AM
Registered User
I am very pleased to receive your reply. On the hardware side, I have all the materials you mentioned in the video. using Openaero VTOL firmware (kk2.0 board). Can you share with this firmware yet? I want to see you on kk2.0 board debugging in the last video. Thank you very much! This is my email: [email protected]
Feb 20, 2014, 12:42 PM
Registered User
Ran D. St. Clair's Avatar
Quote:
Originally Posted by Wanghu
I am very pleased to receive your reply. On the hardware side, I have all the materials you mentioned in the video. using Openaero VTOL firmware (kk2.0 board). Can you share with this firmware yet? I want to see you on kk2.0 board debugging in the last video. Thank you very much!
I will send you the firmware and the user manual information when I get home this evening. It is still in beta test phase, so there may be bugs, but it has been successfully flying for some time now, so hopefully the worst of the bugs are fixed.

The creator of this firmware is HappySundays and the thread relating to it is available here:

https://www.rcgroups.com/forums/show....php?t=1972686
Feb 20, 2014, 02:01 PM
kero burner
jdlilfan's Avatar
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Feb 21, 2014, 01:17 PM
Once you taste flight...
skydvejam's Avatar
Nice been wanting to do something like this. Found you on Testflite first, then to youtube, then to here lol.
Aug 04, 2014, 06:47 PM
Registered User
@Tom Stanton...
Will you please mail your aircraft pdf design to me...It wwill be very helpful for me to get the exact framing
Looking forward to you...!
Email : [email protected]
Aug 05, 2014, 11:31 AM
Registered User
Nice bicopterplane you have allready there Tom. Great job and thank you for the build log.
I wanted to enter in the world of quad but with this thread I thing will change my building plans.
Aug 19, 2014, 04:39 AM
OCD
Wright's Avatar
Quote:
Originally Posted by tom stanton

Hope this makes sense
Hey Tom,

Any updates?
Aug 27, 2014, 03:34 AM
3D Heli Pilot
tom stanton's Avatar
Thread OP
Quote:
Originally Posted by Wright
Hey Tom,

Any updates?
I haven't made any changes to the original design yet, but I am planning to at some point! The original airframe needs to be lighter and more aerodynamic, so I'm thinking of maybe building a profile fuselage for it. It also needs a larger wing area because the stall speed is a bit fast for the current motor/prop setup, which means I'm almost at full throttle during FF just to prevent it stalling.
Sep 05, 2014, 05:30 AM
3D Heli Pilot
tom stanton's Avatar
Thread OP

Update!


I've started work on the next version of this VTOL! The aim of the V2 of this project is to improve flight characteristics now that I know it works. Also, a lot of people have asked me if it is possible to make it fly without the 2 servo combo setup on each nacelle (so the tilt motor is also used for control in a hover). I think it is possible, but the key to making it work is getting the CG (Center of Gravity) as low as possible. If I can make distance between the vertical CG and the motor pivot the same as before, the I see no reason why it shouldn't work. To do this, I will aim reduce the weight of the wing which will lower the CG. I will also implement some dihedral to increase the vertical distance between the lipo and the motors.

So here is a list of things I aim to do:
-Reduce weight (at about 1560kg, the motors are almost at full power in a hover).
-Increase wing area and use an actual airfoil.
-Reduce drag on the fuselage (I will be building a profile fuselage to both reduce weight and drag).
-Build a full moving elevator to make use of any headwind whilst in a hover.
-Lower CG.
-Test if it can be flown with only 1x servo on each wingtip.

Here is an image of the fuselage so far. It's made from 2x sheets of 20mm thick EPP foam glued together to make it 40mm wide. It's 900mm long and 150mm tall


Also I have found a perfect size wing for the project! These were from hobbyking and were designed for the "SkyMule". At a price of about $20 from the UK warehouse, I just couldn't resist! It saves me a lot of effort of building an actual airfoil and will probably perform better than any wing I could make anyway



Sep 05, 2014, 07:18 AM
OCD
Wright's Avatar
Quote:
Originally Posted by tom stanton
I've started work on the next version of this VTOL!
Excellent!!!! I have been looking at these designs and so far yours impresses me the most. If you could add variable pitch props like the ETOC folks fly then you will be able to hover and have better forward flight. Just put it on a slider or mix the pitch on a curve with the nacelle tilt servos. The more you tilt the nacelles the more pitch you need. Ideally you would match the curve to the horizontal speed but I think matching to nacelle position will work. Looking forward to watching.


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