V-tail VS regular - RC Groups
Thread Tools
May 10, 2002, 09:32 AM
Registered User

V-tail VS regular


I've built a terminator HLG with a v-tail, but I feel that I do not have enough control over it. When there are no wind it steers ok, but if there is a little bit of wind it is very hard and if I i.e. steer left it takes a several seconds before it will respond and start to go to the right after I have pulled right.

Will a regular tail give a better control?
When to use v-tail and when to use a regular tail?
What might be wrong with my v-tail?

I'm pretty new to this game so please be patient! (with my english too)

Sign up now
to remove ads between posts
May 10, 2002, 09:45 AM
Registered User
my opinion is that it will control better with a normal tail. But ......
it'll weigh more.

I am going to get slammed for this comment - as many people say that a well setup V tail is as good as a conventional tail - but I have never seen it - so I prefer normal tails.
May 10, 2002, 10:33 AM
Registered User
I agree with you about the standard tails. This thread is probably going to open a big can of worms....but then that is what this forum is for! Also, with the Terminator, if it is just a R/E plane, you can expect there to be a slight time lag from when you input to when the plane actually reacts. My V-tail would do that a lot especially in the wind. One thing you might want to check is if there is ANY slop in your control linkages. If you keep that as small as possible (or better yet, none at all) the plane should react quicker.

The standard tail will probably be easier to set up and I think that if you build it right you can get it as light as a V-tail. V-tails don't seem to get knocked off during landing as much but, then again I have never knocked off a standard tail and I have done some pretty crazy landings. I hope this will help a bit....
May 10, 2002, 11:56 AM
Registered User

Terminator v-tail

I have two Terminators both with v-tails. My response is not so slow as you describe.

Try keeping your speed higher. If you don't have any differential throw in the v-tail (mechanical or through a computer tx) try giving just a touch of down elevator as you initiate the turn. Then once it has rolled into the turn give it just a tad of "up" elevator. May sound counter intuitive but I found it gave smoother turns.

Did you build the Terminator with the specified dihedral?

May 10, 2002, 12:16 PM
Model Designer
keven64's Avatar

Conventional vs V-tail ?

I intend to build a conventional tail on the DLG, and a V-tail on the HLG that I am going to build for the summer.

V-tails do look pretty, but so can the conventional ones . . . I don't fancy preset right rudder with a v-tail

( The DLG model will have a cruciform tail, with all the rudder under the tailplane, slight right rudder trim can be selected to offset the turn induced by the launch, like free flight models. )

Slop in the linkage of either method will cause problems . . .

May 10, 2002, 02:55 PM
Registered User
The problem is not the V-tail itself, but simply because the Terminator has a smallish tail, period. The dihedral is also marginal.
Here is a relevant blurb on the subject:


Terminator modifications
(posting from CRRC email bulletin board, April '01)

The 4" tip dihedral on the 20" tip panels gives 11.5 deg tip dihedral.
This implies EDA = 9.5 deg, which is just barely OK I'd say.
I normally prefer EDA = 12 deg.

Out of curiosity I just now ran a few numbers on the T's tail size.
The equivalent vertical tail volume is 0.019, which is also a bit
smallish. If you want a souped-up Terminator with extra maneuvering
power, I suggest the following mods:

1) Increase the tip dihedral to 4.75". This will give a more generous
EDA = 11.3 deg. If you haven't cut the cores yet, also increase the
tip panel span from 20" to 20.15" so you don't lose projected span.

2) Stretch the tail semi-span from 8" to 9", and increase the tail's
V-dihedral from 35 deg to 39 deg. This will leave the effective
horizontal tail volume roughly unchanged, but it will increase the
vertical tail volume by about 35%.

The extra dihedral and rudder volume will produce about 60% more
roll power. This will make a very "zippy" Terminator.

- Mark Drela
May 13, 2002, 09:15 AM
Registered User
Very good!

I'm about to build a new wing and tail so the information in this forum are helping me a lot.

HLG rocks!

(I also had a 30 min flight with my Precedent Electra Fly. This was hang flying in moderate winds. This was also the longest flight for me. I'm starting to get the hang of it. 300 launches and 31 min flight time all together )
May 13, 2002, 01:16 PM
DAve caNDI,& 5#'s of fury
Dandi6065's Avatar
HI all,
I have been thinking of building a new BUG with a normal tail,any one tried this yet, and how should I size the tail group?
May 13, 2002, 04:49 PM
Registered User
Originally posted by Dandi6065
I have been thinking of building a new BUG with a normal tail,any one tried this yet, and how should I size the tail group?

May 13, 2002, 05:44 PM
89" Kool Aid drinker.
Smash McCrash's Avatar

Bug Cruciform Tail

Here is a pic of someone's cruciform DLG style tail for the Bug. I remember the member saying that they worked well, but, since I haven't built a bug yet, I don't know.

If these are your designs, thanks for them!

May 21, 2002, 01:15 PM
Registered User
John Gallagher's Avatar
Look at the photos section of the Bug group home site. The X tail Bug (Carbon D-Bug) photos are there, including the carbon fiber fuse.


May 22, 2002, 11:44 PM
Gone Soaring

X-Terminator Fuse

Hearing this info about the Terminator not being the quickest on the response I was wondering if anybody has had the same experiences with the fuse the Polecat Aero sells. Mine responds fairly quick and I don't have any complaints but it would be nice if it was a little quicker on the response. I am using the standard wing with the standard dihedral so... Any suggestions or comments? Thanks.

Lee Skidmore
May 25, 2002, 10:48 AM
Registered User
John Gallagher's Avatar
Sorry. the Bug website is :
In the photos section, the Carbon D-bug folder has the photos.

Thread Tools

Similar Threads
Category Thread Thread Starter Forum Replies Last Post
Discussion V-tail vs inverted V-tail khaled_abobakr Ornithopters 15 Oct 04, 2016 04:50 PM