• This site uses cookies. By continuing to use this site, you are agreeing to our use of cookies. Learn more.

RocHobby V Tail 2200mm Owner's Thread

JimCR120

Got Lobstah?
Site Moderator
#1
When I bought the UMX Radian several years ago my intention was merely wanting to spend a relatively small amount of $ that was about to burn a hole in my pocket in the not-so-local hobby shop. On the ride home I was frustrated to find it didn't even have ailerons. "What had I done?" Nevertheless my son said it'll be ok. That was an understatement. A bug bit me. The feel of quietly riding air currents was a thrill I hadn't expected. I was hooked. In my quest for more I bought an Eflite Adagio. Another winner, this time with ailerons and flaps too. I wanted more. Now I have my favorite plane to date:

The RocHobby V-Tail 2200mm
rochobby-v-tail-glider-5ch-2200mm-87-wingspan-pnp-airplane-motion-rc-11275207686_1024x1024.jpg
Though I am a fan of Horizon Hobby products and find the full size Radian somewhat tempting, there is something attractive about a V tail that I like. Interestingly I also have the Durably Zephyr and the Durafly Excalibur which are nice planes but I wanted something that could slow down more without stalling so soon.

Likes
+ Compared to my other gliders its thrust, weight, and lift are at the top.
+ The motor is sufficient on 3S. I think it'll be better on 4S but I haven't got there yet.
+ Flaps
+ Easy to see at a distance
+ Sub $200 price tag
+ I suspect it's a Radian killer.

Dislikes
- Transporting 2.2 meters of aircraft means I can't just stow and go. It does ease this some with the removable pins in the wings.
- I'm having an issue with the motor dropping power. See below.
- The aluminum wing spar bends too easily.

Thoughts for upgrading
+Crow braking, I've never done it but I think I'm close.
+ Lights, I'm not sure if I'd prefer fancy colors like the new Night Radian or just the standard anti collision set like on my UMX Timber. Either way, lighting is a nice touch.
+ Getting my AS3X stabilization on a switch.
+ FPV (I still haven't piloted a fixed wing via FPV).

Regarding the power drop/ motor whine, I haven't troubleshot it yet but the motor whines and doesn't go full power when I give it full power on the stick. Trying a 4S aggravates the problem. I'm suspecting the ESC and will try a different one to see what happens.

I'd really be interested in hearing thoughts/suggestoins from others whether it's about this plane, another like it, or even techniques or max flight times.
 

ElectriSean

Eternal Student
Mentor
#2
Nice glider :) There is something very relaxing about floating around hunting thermals. Other than the V- Tail it looks almost exactly like my Calypso, just a little larger. I never did bother installing flap servos for the funky flight modes, mostly cause I'm too cheap to buy a bigger receiver ;) My longest flight to date is 45 minutes on a 1300 3S, I'm not sure if I'd want to go longer, though a heavier battery would probably get me some better wind penetration. What kind of flight times are you getting?
 

JimCR120

Got Lobstah?
Site Moderator
#3
Thanks for the good info Sean. Now I have something to shoot for.

I don’t know what my record is but I do know I’m getting over 10 minutes of flight time for only five minutes of battery usage. I’ve been using 3S 1000 mAH to get those. I have a couple of 4S 1000 Graphenes that I want to try out which are a bit heavier but I’m looking forward to the extra punch of the 4S.

The receiver I’m using is a Spektrum 6 channel with AS3X which means I cannot put on crow braking and have lights on the switch. If I really want both I will probably rig it up to turn the lights on manually.

Is your calypso running both ailerons off of one servo? If it’s running it off of two you could make your ailerons into flaperons, That is if you are interested in making a go slower and if it can handle it without stalling. I have an Excalibur that I have rigged up with flaperons but I’m having trouble managing the speed on that one. It’s either going way faster than I’m comfortable with for landing or it’s stalling.
 

ElectriSean

Eternal Student
Mentor
#4
Yeah I'm using a Y harness for the ailerons, just using a 4 channel Rx for now. It flies really slow already, and I really have to force it down for landings. Watching it stall is actually funny, it nose dives for a few seconds, picks up a bit of speed and levels out. Flaps definitely aren't needed, but it would be neat to play with spoilers and crow one day. Too many other projects on the go right now though ;)
 

JimCR120

Got Lobstah?
Site Moderator
#5
Desync?
I don't think I've ever experienced desync but maybe now I am. What are the signs/symptoms of a desync? Would my motor whine problem I described in the OP be desync? If so what might fix it? I know I the ESC has options I could change.

I want to work on this today and hopefully resolve it so I can get this beautiful bird back where she belongs.

Anyone?
 

ElectriSean

Eternal Student
Mentor
#6
Desync happens when the ESC loses track of the motors position and causes it to jitter or stall completely. The first thing I would look at is the wiring and connectors, but playing with the ESC settings could help. Motor timing and demag compensation are the settings you're after.
 

JimCR120

Got Lobstah?
Site Moderator
#7
Thanks. It only happens when I punch the throttle on 3S or if I use 4S even with low throttle. It makes a whiney sound and doesn't hardly provide any power, not enough to climb for sure. I have other ESC's and motors to confirm I'm on the right track but I do suspect it's a setting in the ESC. I'll post back with what I find.