HobbyKing.com New Products Flash Sale
Reply
Thread Tools
Old Aug 23, 2010, 06:45 PM
Walter Roos
ROOSWH's Avatar
Canton, Ga.
Joined Aug 2004
3,196 Posts
Alex,
Looks like you go for some heavy duty wiring.
Nice flying at the German Open.

walt
ROOSWH is offline Find More Posts by ROOSWH
Reply With Quote
Sign up now
to remove ads between posts
Old Aug 25, 2010, 03:03 AM
Registered User
Joined Jul 2007
180 Posts
Experiment with turbulators.

to find out if it is possible to further improve the behaviour of the Twister 2 in slow turns I placed turbulators of 0.3 mm thick and a lenght of about 14 cm at the tips.

I fly about 2 month now with the turbulators and concluded that:

- I do not notice difference in launch hight (but expect from theoretical point of view that there must be a small disadvantage).
- I do not notice difference in stall behaviour.
- I do notice that the ailerons feel more direct when flying against stall speed.

Due to the last I decided to let them on (also during the German Open).

P.s. this is an old picture, I removed the part of the turbulator that is outboard of the aileron.


Bas Breijer
Bas B is online now Find More Posts by Bas B
Last edited by Bas B; Aug 25, 2010 at 03:13 AM.
Reply With Quote
Old Aug 25, 2010, 03:13 AM
Hugh Blackburn
floquet's Avatar
Melbourne, Australia
Joined Jun 2005
489 Posts
Quote:
Originally Posted by Bas B View Post
- I do not notice difference in launch hight (but expect from theoretical point of view that there must be a small disadvantage).
- I do not notice difference in stall behaviour.
- I do notice that the ailerons are more direct when flying against stall speed.

Due to the last I decided to let them on (also during the German Open).
Hi Bas, that's interesting. (I have cut these kind of turbulators before, but never used them near the hinge line, and not on Twisters.) I don't suppose you have any similar experiences with a Twister 1? I'm still flying my T1 as I build my T2s. Twister 1 has narrow tip chord and suffers from that in low-speed turns. Your fix might significantly improve that, and remedy the main T1 deficiency. Any comments?

Hugh
floquet is offline Find More Posts by floquet
Reply With Quote
Old Aug 25, 2010, 03:23 AM
Registered User
Joined Jul 2007
180 Posts
Quote:
Originally Posted by floquet View Post
Hi Bas, that's interesting. (I have cut these kind of turbulators before, but never used them near the hinge line, and not on Twisters.) I don't suppose you have any similar experiences with a Twister 1? I'm still flying my T1 as I build my T2s. Twister 1 has narrow tip chord and suffers from that in low-speed turns. Your fix might significantly improve that, and remedy the main T1 deficiency. Any comments?

Hugh
Hugh,

I owned four Twister 1's. What I noticed was that the one's with the light wings behaved very well in the turns (but not as good as a Twister 2) and the ones with the heavier wings behaved less good. I have done similar experiments with turbulators on the Twister 1's with the havier wings but I did not notice any improvement, so I removed them.

Bas
Bas B is online now Find More Posts by Bas B
Last edited by Bas B; Aug 25, 2010 at 03:52 AM.
Reply With Quote
Old Aug 25, 2010, 04:18 AM
Alex Hoekstra's Avatar
Hurdegaryp Netherlands
Joined Feb 2007
394 Posts
I also did a test with the same turbulator like Bas. I also couldn't realy detect any launchhighed difference but i also couldn't detect any behaviour difference in turns. The only thing i could detect is that gliding in very strong winds with a lot of ballast became less good. It was harder to put a lot of speed on the plane. I removed them again. I feel that a CG change of 1 mm in turbulent air makes a lot more difference in behavior then the turbulators did.
Alex Hoekstra is offline Find More Posts by Alex Hoekstra
Reply With Quote
Old Aug 25, 2010, 05:58 AM
Registered User
Joined Jul 2007
180 Posts
Alex,

because the effect of the air you fly in is much bigger than the effect of the turbulator it is very difficult to judge what is placebo effect and what is real effect.

With 120 grams ballast it goes against strong winds like a rocket in good air and in really bad air it is more difficult to keep the pace. This is the same behaviour as it had without turbulators (and this behaviour is normal for any plane).
I still feel comfortable with the turbulators and that is why I let them on.

Bas
Bas B is online now Find More Posts by Bas B
Last edited by Bas B; Aug 25, 2010 at 08:47 AM.
Reply With Quote
Old Aug 25, 2010, 09:41 AM
usaf3kteam
rcgeorge's Avatar
Joined Sep 2005
5,703 Posts
Quote:
Originally Posted by Bas B View Post
to find out if it is possible to further improve the behaviour of the Twister 2 in slow turns I placed turbulators of 0.3 mm thick and a lenght of about 14 cm at the tips.

I fly about 2 month now with the turbulators and concluded that:

- I do not notice difference in launch hight (but expect from theoretical point of view that there must be a small disadvantage).
- I do not notice difference in stall behaviour.
- I do notice that the ailerons feel more direct when flying against stall speed.

Due to the last I decided to let them on (also during the German Open).

P.s. this is an old picture, I removed the part of the turbulator that is outboard of the aileron.


Bas Breijer
Why is your peg in such of an angle?
rcgeorge is offline Find More Posts by rcgeorge
Reply With Quote
Old Aug 25, 2010, 11:47 AM
Registered User
Joined Jul 2007
180 Posts
Quote:
Originally Posted by rcgeorge View Post
Why is your peg in such of an angle?
George,

this is done because some people in Holland claims that a plane launches higher when the peg has such an angle. I do not know if it is true, just following the others.

Bas
Bas B is online now Find More Posts by Bas B
Last edited by Bas B; Aug 25, 2010 at 11:56 AM.
Reply With Quote
Old Aug 25, 2010, 12:25 PM
Registered User
Joined Jun 2010
16 Posts
Alex Hoekstra Hello, Congratulations, you get the first five, I would like to ask you about my T2 large vibration also lost when the RDS will have to resolve the parties try it? Sorry my English is not very well hope to see you understand. Taiwan arrow:)
arrowho is offline Find More Posts by arrowho
Reply With Quote
Old Aug 25, 2010, 02:41 PM
Throw it like you hate it
RCPC's Avatar
United States, CA, Castro Valley
Joined Apr 2007
3,085 Posts
Quote:
Originally Posted by arrowho View Post
Alex Hoekstra Hello, Congratulations, you get the first five, I would like to ask you about my T2 large vibration also lost when the RDS will have to resolve the parties try it? Sorry my English is not very well hope to see you understand. Taiwan arrow:)
I experienced flutter on my T1's and to resolve it I first sealed the hinge gap with tape. That worked for a while, but then I was getting flutter at the tips. I then filled the hinge with silicone. So far, it has worked great. Good luck.
Paul
RCPC is offline Find More Posts by RCPC
RCG Plus Member
Reply With Quote
Old Aug 25, 2010, 03:16 PM
Alex Hoekstra's Avatar
Hurdegaryp Netherlands
Joined Feb 2007
394 Posts
Quote:
Originally Posted by arrowho View Post
Alex Hoekstra Hello, Congratulations, you get the first five, I would like to ask you about my T2 large vibration also lost when the RDS will have to resolve the parties try it? Sorry my English is not very well hope to see you understand. Taiwan arrow:)
Flutter with RDS is very easy to solve by slipping in thin layer of prefabricated glass(25 0r 50 gr/m2) into the pocket. A fraction of 5 min epoxy wil hold it on its place. Keep the aileron moving during drying will make sure everything will stil moving smoothly afterwards.
Alex Hoekstra is offline Find More Posts by Alex Hoekstra
Reply With Quote
Old Aug 25, 2010, 03:19 PM
Registered User
Joined Jul 2007
180 Posts
Paul,

the Twister 1 has a flexible hinge and the Twister 2 has a kevlar hinge. Therefore, silicone will not prevent flutter on a T2.

Bas
Bas B is online now Find More Posts by Bas B
Last edited by Bas B; Aug 27, 2010 at 03:03 AM.
Reply With Quote
Old Aug 25, 2010, 11:51 PM
Registered User
Joined Jun 2010
16 Posts
Quote:
Originally Posted by Alex Hoekstra View Post
Flutter with RDS is very easy to solve by slipping in thin layer of prefabricated glass(25 0r 50 gr/m2) into the pocket. A fraction of 5 min epoxy wil hold it on its place. Keep the aileron moving during drying will make sure everything will stil moving smoothly afterwards.
I roughly know what you mean, I'll try. Thank you
arrowho is offline Find More Posts by arrowho
Reply With Quote
Old Aug 29, 2010, 08:03 AM
Hugh Blackburn
floquet's Avatar
Melbourne, Australia
Joined Jun 2005
489 Posts
Quote:
Originally Posted by Alex Hoekstra View Post
2 x D 47 behind there and enough space for the ballast tube. D47 are perfect servo's for a pull/spring set up and will never give up and can handle very strong spring tensions.
Can you guys recommend rudder and elevator horn radii from hinge lines to suit d47s? (And T2s of course.)

Thanks
Hugh
floquet is offline Find More Posts by floquet
Reply With Quote
Old Aug 29, 2010, 08:11 AM
Alex Hoekstra's Avatar
Hurdegaryp Netherlands
Joined Feb 2007
394 Posts
Quote:
Originally Posted by floquet View Post
Can you guys recommend rudder and elevator horn radii from hinge lines to suit d47s? (And T2s of course.)

Thanks
Hugh
10 mm for both rudder and elevator. For the elevator the hole is slightly behind the hingline because the steeringline come in under a slight angle from below.

Alex
Alex Hoekstra is offline Find More Posts by Alex Hoekstra
Reply With Quote
Reply


Thread Tools