Hi Guys,

I was a little bit board .....
This is a promo for a full Comparison between two nice Dlg's

At first i made a Vid of Launching Sound

FW5 Vs. Helios DLG Launching Sound (0 min 39 sec)

Gil

Great video !!!

I prefer the way FW5 sounds !!!

The FW5 has a hollow wing and the Helios has a wing with a full Rohacell core. This difference certainly has influence on the sound.

Bas

sweet launch, the fw5 sounds wicked

Originally Posted by Bas B

The FW5 has a hollow wing and the Helios has a wing with a full Rohacell core. This difference certainly has influence on the sound.

Bas

Do you remember the sound of the T3 or mostly the lack of it. Hollowmolded wing.

@Gil, Did you cover the gabs from the Fw5? It sound dragy.

I have two Flows and they're never noisy when launching. Actually no difference with my Stobel or Salpeter : zero noise, nice launch heights. Sounds like yours has a bad cold and wants to sneeze everytime you sling it.
Bless you !

I remember how my T2 sounded before I gap sealed it... and the crinkling sounds that I could then hear every time I launched it after the gap seal.

Bas B is right... when I watched the video the first thing I thought was the difference between a non-gap sealed hollow wing and a solid molded wing.

Originally Posted by Alex Hoekstra

Do you remember the sound of the T3 or mostly the lack of it. Hollowmolded wing.

@Gil, Did you cover the gabs from the Fw5? It sound dragy.

Hi Alex,
Congrats on the T3

What do you mean gabs ? (Gaps ?) and where? dragy ? please explain

Originally Posted by ydevriendt

I have two Flows and they're never noisy when launching. Actually no difference with my Stobel or Salpeter : zero noise, nice launch heights. Sounds like yours has a bad cold and wants to sneeze everytime you sling it.
Bless you !

It is interesting why mine make that sound and yours isn't

I might think that mine is a bit afraid when he realize then soon he's going to meat some clouds and might get bad cold since you'r right, it is chilly up... there around the 200ft heights

But really , why mine make that noise and yours doesn't ?
I am using the Swindell stabs, is that might be the reason?

Gil

Do both planes use the same type of aileron linkage? It sounds a lot like the noise an exposed bottom linkage makes, but that wouldn't explain it if they're both the same.

The sounds could be coming from the flapperons not being at the optimal setting. I know my blasters used to make a terrible racket if I had my launch mode switch in the wrong position.

Well at least the Helios launching sounds the same as mine

Having built Gil's model and having its sister ship as my own (along with another) I can say that it has gap seal in the wings and the noise is either amplified from the hollow wing (resonance) or caused by the hole at the bottom of the fuse (used to connect the pushrods to the ailerons and can be easily taped over). The model itself is very clean aerodynamically and launch altitude is on par with other models I've launched such as the Helios and Steigesen which goes to show that the model isn't "dragy" but rather conventional in that regard.

Originally Posted by roydor

Having built Gil's model and having its sister ship as my own (along with another) I can say that it has gap seal in the wings and the noise is either amplified from the hollow wing (resonance) or caused by the hole at the bottom of the fuse (used to connect the pushrods to the ailerons and can be easily taped over). The model itself is very clean aerodynamically and launch altitude is on par with other models I've launched such as the Helios and Steigesen which goes to show that the model isn't "dragy" but rather conventional in that regard.

Of course . . . if you guys don't tape the hole in the fuselage bottom for connecting the pushrods ?

On a more general basis : every whistle or sound produced by a glider indicates drag. So tape all the gaps and holes up carefully, alternatively use earplugs for launching

Lots can be learned from gap sealing on "real" gliders : for instance this site http://www.gliderservice-novak.si/en...l-surface.html

Gap sealing not only eliminates aerodynamic noise, but improves performance and effectiveness on all control surfaces. And you can throw your earplugs in the trashcan or sell them on E-bay

Yves

Originally Posted by Beetle-Jet

Hi Alex,
Congrats on the T3

What do you mean gabs ? (Gaps ?) and where? dragy ? please explain

Gil

The space between the aileron and wing over the hingeline. Does it have some sort of tape to cover it or is it all open?

Originally Posted by Alex Hoekstra

The space between the aileron and wing over the hingeline. Does it have some sort of tape to cover it or is it all open?

Hi

Tested today with my DLG sister plane (roy's dlg ) and we go through all the hinge line tape, all in place and secured.
Also if not mentioned early, the hatch of the ailerons linkage is also covered with tape.

Roy FW5 dlg makes a soft Whistle noise similar to the Helios, but mine still make a loud Whistle,
I find mine much more interesting, like a nice echo of rifle shot ( like old western movies)

As long as it doesn't hurt my launch high i can live with it.

Gil