New 1.2 meter wing tested

[Jorn]

Bjørn,

I am no expert in r/c planes, but as an engineer I would in general think what matters most - to least would be;
- bad adjustments of the neutral points of the ail.servos,
- any malformity of the wings or ails, (e.g. Resulting from heat in the film-covering prosess),
- wrong thrust-line for the motor,
- a few cm off in the sideways gc-placement.

Btw, Nice thread!

Jorn

[icebear]

Bjørn,

I am no expert in r/c planes, but as an engineer I would in general think what matters most - to least would be;
- bad adjustments of the neutral points of the ail.servos,
- any malformity of the wings or ails, (e.g. Resulting from heat in the film-covering prosess),
- wrong thrust-line for the motor,
- a few cm off in the sideways gc-placement.

Btw, Nice thread!

Jorn

Thanks Jorn!
Good points!
I think that it could be that the wing is not perfectly straight and I am not super happy about the covering and aileron attachments with tape.
I will redo the covering using laminate instead and fix the ailerons with proper hinges to see if that helps.
In any case I am very happy with the wing as such otherwise - feels very efficient. I did another 300m altitude test today wich worked out fine.

/Björn

[icebear]

I decided to take off the Orastik covering (save 40 grams!) and reattach the ailerons with proper hinges to make sure the ailerons are pefectly straight.

I have ordered some laminate from Joost in Germany and hope that it will be better than tape and covering hich I already have tested with poor results on EPP. I use 3M77 spray but even with that it has been hard to get a smooth surface.

Any thoughts about alternatives welcome, epoxy for example?

Here's a video from the last flight before the re-work - a full auto 300m circle climd and short square routa and auto landning.

https://vimeo.com/48461049

/Björn

[Tom]

Maybe the questions should be why you want a smooth colored surface?
If you like color, EPP paint can be an easy and lightweight solution.

Smoothness? The smaller your wing, the less it matters. At a certain scale, having a rough surface is actually more efficient (think of the little holes they make in golf balls).

But I must admit smooth looks cooler and cleaner

[Captain Future]

Maybe the questions should be why you want a smooth colored surface?
If you like color, EPP paint can be an easy and lightweight solution.

Smoothness? The smaller your wing, the less it matters. At a certain scale, having a rough surface is actually more efficient (think of the little holes they make in golf balls).

But I must admit smooth looks cooler and cleaner

Hi, Tom
It's not about beautiful surfaces. Coat the surfaces with foil or laminate makes the wings and rudder much stiffer. Foil and laminate must be ironed so that it connects to the EPP. Color alone does nothing.

On Sunday I start my 4th Flight. But this time with my Mycrocam. Hope to present you beautiful shots.
Eddi.

[Captain Future]

Hi Tom,
It's not about beautiful surfaces. Coat the surfaces with foil or laminate makes the wings and rudder much stiffer. Foil and laminate must be ironed so that it connects to the EPP. Color alone does nothing.

On Sunday I start my 4th Flight. But this time with my Mycrocam. Hope to present you beautiful shots.
Eddi.

[icebear]

Maybe the questions should be why you want a smooth colored surface?
If you like color, EPP paint can be an easy and lightweight solution.

Smoothness? The smaller your wing, the less it matters. At a certain scale, having a rough surface is actually more efficient (think of the little holes they make in golf balls).

But I must admit smooth looks cooler and cleaner

Well, I just removed the covering and finished up the ailerons etc and my wife said; "It looks more functional now, but it looked better in red" - that sums it all up, I think...

I actually thought that it would be a little more efficient with a smooth surface but maybe the extra weight doesnt pay off and then there is of course the golf ball effect...

Here's a picture of the re-worked wing with just some tape over the carbon reinforecmnts and leading edge etc. Will report back after re-maiden tomorrow!

/Bjorn

[icebear]

Update!

After some EMF issues I have re-routed the power cables so that they no longer go under the PCB and I also took the opportunity to make a GoPro Hero2 moung in the wing.

First flight was successful - I just had to re-trim and move the battery back a bit to get the right CG.

I am starting to like the Glider 1200 wing!

AUW is now aprox 630 grams with the camera and battery.

Cheers!

Björn

[Tom]

I am still amazed on the low weight of custom build wings!

Can't wait for a high altitude flight with a full HD camera!

[icebear]

I am still amazed on the low weight of custom build wings!

Can't wait for a high altitude flight with a full HD camera!

OK, here you go!

http://www.youtube.com/watch?v=MIVJYFRPqCc&feature=share&list=UUpkvg9XoKY5zbuBFPXiyvfg

It's only 200 meters altitude but I think it shows that the video is sharper than the other cameras.

I have also noted that the windsock and wind metering in the GCS in my opinion is a little conservative.
I have a wind meter that is available online nearby and from my previous experineces with UAVs I have found this meter to be quite accurate. Yesterday we had avg windspeed of 6.5 m/s and around 9 m/s in the gusts. The windsock showed around 3-4 m/s which by just looking at the upwind/downwind speed doesn't seem accurate. Does anyone have the same experinece?

/Bjorn