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macr0t0r · Jun 30, 2009, 12:48 AM

Finished ATTF #99: RadioCarbonArt. Comments!

=== Hitec Aurora TX ===
First off, a couple links to the goods so you know what we are talking about:
http://www.hitecrcd.com/transmitters/show?name=Aurora+9
http://www.rcheliresource.com/detail...-radio-system/

(Sniff) I remember back when Hitec was this little baby company that was making cheap, 3rd-rate crap so that the Futaba owners could actually afford more than one receiver and servo. Who would've thought they'd make it this far when they grew up?

Admittedly, I'm a JR (and therefore Horizon) fan, but I've realized that it's because JR and Hitec use two very different control organizations and that it's mostly a user preference.

I think the feature I find most intriguing in the Aurora is the two-way telemetry. If done right (the modules are not available yet), this could be a real nice supplement to an FPV system! However, I don't see a way to back up your settings. If I were to spend this kind of money to program in 30 airplanes with settings of this detail, I would really want a way to back it up! Can anybody correct me on this?

Snap Roll buttons! Nostalgia! I use to have those on my old Airtronics Module 7P! Yes, fun times. Do a low fly-by with the Ugly Stick, reach for the elevator dual-rate, then walk out with a plastic bag to pick up the pieces. Those devilish little buttons were too easy to tap. I ended de-programming all but one, which was setup to trigger the bomb bay.

About the timer. Diggs or Jamie were talking about wanting to get the total flight time from the Spektrum DX7 TX. After the timer finishes countdown, it immediately counts up like a stop watch. Total flight time is just the ending time plus the countdown time. Good enough for most of us.

=== Airfoil? We still use those? ===
Airfoils use to be a really critical design aspect back when we actually flew on the WING.

However, we've gotten to where any wing will fly. It's awesome to hear from Paul that the airfoil development is still going full-tilt with the silent flyers!

As far as adding texture to a wing surface to reduce friction...well, it's a finicky thing to figure out. The concept is that you "dimple" the surface to create little mini-balls of turulence that the air-flow can ride across (like ball bearings). However, we still aren't very good at modeling turbulence, and the effectiveness of the dimples is a a combination of surface area, depth, reynolds, and (unfortunately) velocity! I've heard tails of how fabric covering was more efficient than monocote, but it's hard to find an exact pattern of results. However, there are real results, and you can find a few actual studies, such as this one (PDF 3.3MB):
http://www.iea-ia-amt.org/psds/20%20...20Nov%2006.pdf

=== Kline Fogleman Airfoil ===
I'll be honest, I just can't tell if this thing could actually work, or if it's just snake-oil. It defies what aerodynamics I'm familiar with. For what it's worth, here is an article with references to the patents:
http://www.rexresearch.com/klinfogl/klinfogl.htm
You can make a neat little paper airplane with the airfoil:
http://www.instructables.com/id/The-...aper-Airplane/
And, here is the main forum thread on the subject:
http://www.rcgroups.com/forums/showthread.php?t=558321

Shame about MSComposites. 'nuff said.

I confess I hadn't heard of RadioCarbonArt before. Yet another reason to love this podcast. Thanks!

- Jim

Jun 30, 2009, 12:48 AM	#2741
macr0t0r Got more toys than my kid Join Date: Sep 2004 Location: Fremont, CA Posts: 3,390	Finished ATTF #99: RadioCarbonArt. Comments! === Hitec Aurora TX === First off, a couple links to the goods so you know what we are talking about: http://www.hitecrcd.com/transmitters/show?name=Aurora+9 http://www.rcheliresource.com/detail...-radio-system/ (Sniff) I remember back when Hitec was this little baby company that was making cheap, 3rd-rate crap so that the Futaba owners could actually afford more than one receiver and servo. Who would've thought they'd make it this far when they grew up? Admittedly, I'm a JR (and therefore Horizon) fan, but I've realized that it's because JR and Hitec use two very different control organizations and that it's mostly a user preference. I think the feature I find most intriguing in the Aurora is the two-way telemetry. If done right (the modules are not available yet), this could be a real nice supplement to an FPV system! However, I don't see a way to back up your settings. If I were to spend this kind of money to program in 30 airplanes with settings of this detail, I would really want a way to back it up! Can anybody correct me on this? Snap Roll buttons! Nostalgia! I use to have those on my old Airtronics Module 7P! Yes, fun times. Do a low fly-by with the Ugly Stick, reach for the elevator dual-rate, then walk out with a plastic bag to pick up the pieces. Those devilish little buttons were too easy to tap. I ended de-programming all but one, which was setup to trigger the bomb bay. About the timer. Diggs or Jamie were talking about wanting to get the total flight time from the Spektrum DX7 TX. After the timer finishes countdown, it immediately counts up like a stop watch. Total flight time is just the ending time plus the countdown time. Good enough for most of us. === Airfoil? We still use those? === Airfoils use to be a really critical design aspect back when we actually flew on the WING. However, we've gotten to where any wing will fly. It's awesome to hear from Paul that the airfoil development is still going full-tilt with the silent flyers! As far as adding texture to a wing surface to reduce friction...well, it's a finicky thing to figure out. The concept is that you "dimple" the surface to create little mini-balls of turulence that the air-flow can ride across (like ball bearings). However, we still aren't very good at modeling turbulence, and the effectiveness of the dimples is a a combination of surface area, depth, reynolds, and (unfortunately) velocity! I've heard tails of how fabric covering was more efficient than monocote, but it's hard to find an exact pattern of results. However, there are real results, and you can find a few actual studies, such as this one (PDF 3.3MB): http://www.iea-ia-amt.org/psds/20%20...20Nov%2006.pdf === Kline Fogleman Airfoil === I'll be honest, I just can't tell if this thing could actually work, or if it's just snake-oil. It defies what aerodynamics I'm familiar with. For what it's worth, here is an article with references to the patents: http://www.rexresearch.com/klinfogl/klinfogl.htm You can make a neat little paper airplane with the airfoil: http://www.instructables.com/id/The-...aper-Airplane/ And, here is the main forum thread on the subject: http://www.rcgroups.com/forums/showthread.php?t=558321 Shame about MSComposites. 'nuff said. I confess I hadn't heard of RadioCarbonArt before. Yet another reason to love this podcast. Thanks! - Jim