What is the L/D penalty of outside mounted GoPros?

On Sunday, January 11, 2015 at 1:58:55 PM UTC-8, Andy Blackburn wrote:
On Tuesday, January 6, 2015 at 9:59:38 PM UTC-8, Surge wrote:

Maybe someone would like to make GoPro fairings for glider pilots.

Like this?

https://drive.google.com/file/d/0Bw1...ew?usp=sharing

9B

https://drive.google.com/file/d/0Bw1...ew?usp=sharing

https://drive.google.com/file/d/0Bw1...ew?usp=sharing

9B

Andy, thanks for playing around with the farings idea. How much drag do you really think this would save? I think it would be a fun project.

Bruno - B4

On Sunday, January 11, 2015 at 8:48:15 PM UTC-8, wrote:
Andy, thanks for playing around with the farings idea. How much drag do you really think this would save? I think it would be a fun project.

Bruno - B4

I you look up drag of different shapes, a flat plate (Go Pro) has a drag coefficient of 1 or more. A contoured airfoil-type shape has a drag coefficient of 0.1 to 0.2 so it would seem to make a fair amount of difference.

My 3D printer is on the fritz, but once I get it working again I should be able to crank one of these out in a day or so.

On Sunday, January 11, 2015 at 10:54:40 AM UTC-5, wrote:
On Saturday, January 3, 2015 at 12:55:47 PM UTC-8, wrote:
I am thinking about trying to do some soaring videos. Inside the cockpit footage only is boring and I want to be more like Balleka with amazing outside camera shots. The reason why I haven't done much is concern over the performance penalty of outside cams while trying to do longer XC flights..

Anyone smarter than me (I know most of you are, other than TT) able to figure out the drag penalty of a GoPro either mounted on the wing or on the tail of a 27? It would be attached with the adhesive mount and not the larger suction cup mount in hope of reducing the drag. The GoPro in its larger case to accommodate an extra battery is 41mm H x 59mm W x 40mm D.

What I am hoping to figure out is if it is a 1-2 point L/D penalty or something more like a 4-5 point drop. Those of you who have flown with me know I need every L/D point I can get.

Here's to hopefully a lot of fun 2015 soaring videos shared from a bunch of us!

Bruno - B4
Oh yeah - and Nephi is amazing!

Bruno, Don't change a thing, your YouTube videos are amazing. Keep up the good work. You have quite a fan base.

CAN'T be any worse than "downgrading" to an ASW-20 from your 27.

Bruno,
These camera's are already in that shape.

http://store.driftinnovation.com/dri... HNxoCT2Hw_wcB

But I agree, those fairings look cool, and it would be a fun project.

Put enough cameras on, Bruno, and the plane may glide backwards because of all the drag! Want serious glide degradation, you needed to talk with Oscar Boesch about carrying an early I-Max camera on his AS-W15. Pictures in a back issue of SOARING. Oscar left us in 2012.

Maybe camera used by Sebastian Kawa in Nad Annapurna video would be better than multiple cameras. See 9:20 in http://youtu.be/4UdfTZ3bf9E.

On Tuesday, January 13, 2015 at 2:39:21 PM UTC-8, Ivan Volny wrote:
Maybe camera used by Sebastian Kawa in Nad Annapurna video would be better than multiple cameras. See 9:20 in http://youtu.be/4UdfTZ3bf9E.

Bruno,

Here are a couple of links to external camera rigs I've tried in the past. Both were shot at Parowan FWIW. The first dates from 2005 when the best available solution required a remote bullet camera hard-wired to a digital video tape-based camcorder.

https://www.youtube.com/watch?v=BXbfs0tzqbQ

The second one is from 2012. A GoPro mounted to a piece of aluminum channel stock mounted to the wingtip. Issues with framing and vibration, but promising.

https://www.youtube.com/watch?v=Vv-GTknLkQE

Hope that helps as you think about possible camera locations. I have a few more ideas to pursue - including a cheap version of a panning camera you can mount externally.

Looking forward to Nephi this summer.

Andy - 9B

I can say from personal experience that a Super Cub wingtip
inserted (in flight) into the wing of a Nimbus 3 reduces its
performance to about Ka8 level, not all due to the full rudder
required to fly straight.

Total drag of a sailplane equals AUW divided by L/D, typically
around 25 lbs force (or 120 or so if you insist on SI units). Go-Pro
Cameras aren't very aerodynamic. OK when flying for fun, but not
seriously.

At 22:46 12 January 2015, Steve Leonard wrote:
Put enough cameras on, Bruno, and the plane may glide
backwards because of
=
all the drag! Want serious glide degradation, you needed to talk
with
Osca=
r Boesch about carrying an early I-Max camera on his AS-W15.
Pictures in
a=
back issue of SOARING. Oscar left us in 2012.