|Jan 23, 2012, 08:31 PM|
|Jan 28, 2012, 08:46 PM|
Joined May 2003
Can anybody tell me if you guys have used and recorded a flight from start to finish that records Airspeed and Groundspeed.
A group of us are interested in where during the flight the stress is put on the airframe.
The telemetry systems I see use GPS style referencing or radar type. I was hoping that someone had used an onboard pitot style airspeed indicator.
If so can you point me in the direction of where I would find this information.
|Jan 29, 2012, 07:16 AM|
I think the DS community will eventually have to keep multiple records.
Records for ground speed as now, records for sustained (some pre determined time interval) airspeed and peak airspeed. There would also have to be a way of confirming pitot accuracy and possibly recalculating pitot speeds to match whatever calibration techniques are used.
Hmm... Souns like FAI! Nah... Forget I brought it up.
Pitot speeds are for bragging rights and ground based radar is rather foolproof and confirmable without reference to the plane.
Hmm... Again! How about an on board computer that reads the incoming radar and transmits a spurious signal calculated to lie about the speed you are going. If the spurious signal is 40 dB or so stronger than the true signal then the truth is hidden in the noise.
Skip all this telemetry. Just build an echo lying device.
I need one for my car.
|Jan 29, 2012, 11:43 AM|
Riverside, California, United States
Joined Aug 2004
Met Alan yesterday afternoon at Parker to maiden his new D80 with stability system. This in my opinion was a historical flight for dynamic soaring. This system is incredible and it worked flawlessly. To be fair, I didnt spend much time trying to dial in the plane and groove with the autopilot off as it was trying to roll me out every lap and when I turned it on it was like flying in the smoothest air possible. I think Spencer said it best, it's like playing a video game. The plane does exactly what you tell it to do. I wend about 250 or so with it off but with it on I could constantly go 290-300.
Yesterday in corona I was trying out a new spot that had lots of energy but soon got rolled into the hill and lost the model. I think this spot can produce record speeds as it regularly gets 60+ winds as with a few other spots I know of. If I had this system in my D60 yesterday I would have likely gone very fast and still had a model to go home with. We are now putting one in my D130. I understand both views on this new "cheater" system but at the end of the day, we all want to go faster and not break planes. Wether we accept this system or not Im positive that in the very near future just about everyone will be using one. Im not going to pass up the oppurtunity to try one out. Thanks again Alan for all the hard work your doing. In a years time you have become one of the biggest contributors to our hobby. Time to go faster!!!!
|Jan 29, 2012, 12:19 PM|
Gyro's are ok,I'm all about not crashing,I just think it needs to be noted that a gyro is being used vs. no gyro. There is a huge diff.
|Jan 30, 2012, 01:56 AM|
I agree it should be noted. There is a huge difference. I've had a high quality airplane specific
HH gyro in my D60 for about a year and it has allowed me to go fast in what would
otherwise be unflyable air, and to fly *really* close to the ground in "normal" air. It
makes it a lot easier to point the plane at the gun safely. For the most part,
it just makes my totally unballasted D60 feel like a large tip ballasted D80.
I've used it in a couple new (to me) grooves, and one of them was just brutally nasty,
but gyro kept the plane alive and likely doing 200+mph. The other has turned out to be pretty decent
and I've matched my gyro'd speeds with another person's D60 with no gyro in the same air.
BTW, one thing about a HH gyro is that as long as Tx trim is centered it will maintain
a fixed attitude even if the plane itself needs trim to fly properly without the gyro. Some
HH gyros will let you switch em off remotely, trim the plane properly, and then turn gyro
back on, and it uses that as the new center (have to keep hands off sticks
when you turn it on). Most however do not, which means if you launch
the plane out of trim with Tx trims centered, you can only fly it straight with the gyro
turned on. If you turn it off the plane start to roll. If you retrim, and then turn gyro back
on, it'll see the new trim as roll input and start rolling continuously. It sounds like
the D80 Joe flew was doing that. Being able to reset the "center" position for the
gyro when it's swtiched on remotely, is very useful.
|Jan 30, 2012, 04:59 AM|
A gyro responds almost instantly, but the time delay between hand and eye is about two fifths of a second so most normal people would be that far behind any unexpected movement of the plane.
If I wasn't so lazy I'd calculate how far a plane can move in two fifths of a second at two hundred mph.
BTW, the two fifths of a second hand to eye stuff is what he quick draw aficionados claim. The say if you can draw in less than two fifths of a second you can shoot first even if someone is pointing a gun at you.
I wouldn't bet my life on it! I would however trust them to have measured that response often enough to be certain.
|Jan 30, 2012, 06:46 AM|
Couldn't find anything on reflex response time, but found this and am totally amazed. Of course it's a rehearsed and practice action but even so the speed is beyond belief.
Sorry, I know it's off topic. I do hope to find something on eye to hand reflex arc speed, which is pertinant to gyro vs non-gyro flying.
Edit: Here's something that confirms my original post. Kinda weird. I know I'd be dead by now if my brake foot was this slow.
Check it out. I'm going to research some more.
Edit two: Wherever I look the given range is 0.15 to 0.3 milliseconds. I have to conclude that what we do when we fly is not in the same category as simple response time. I'm also appalled by something I read about driving. That article suggested that most drivers take 1.5 seconds to respond on their brakes. I really can't believe that, though I'm sure that a large number of drivers aren't paying that much attention to what they are doing.
|Aug 02, 2012, 03:01 PM|
At one point I understood Alan was going to put togethet a telemetry box and sell it as a module for the A9. Is this happening? Is there a link for information?
|Aug 06, 2012, 06:14 PM|
Joined Oct 2005
Stability systems are available:
I have had 50 airborne boards and 25 speaker box boards assembled. The speaker box uses the Hitec telemetry system case, but has different internal parts.
The stability system can be used with any radio, but the telemetry features require the Aurora 9 Tx and the Optima 9 or 7 Rx. The speaker box records the last 165 minutes of flight data, which can be viewed with a PC and the included software. I have flight tested model settings files for many popular DS models including the D60,80,130, Thundertaker, Opus MCT, JW60, and Sunbird. The settings will still need to be adjusted for each installation using the PC interface.
Please note that the system setup will require careful installation of the air probes, wiring and the sensor module, learning how to use the PC interface software, and a few flights to adjust the model's response. It is not simple "plug it in and fly" type of accessory.
Here is the current pricing:
Airborne module $200
Speaker and data recording box $100
Programming cable with 2 adapters $25
Wiring harness (D80 style, fuselage side only) $50
Probe kit: 2 ea machined 1/8” tubes for static and pitot tubes (4 total), 1 ea 3 cavity delrin tip mold, 2 ea “T” fittings, 2 ea barbed couplers, nylon tubing for probe mounts, 3m Teflon tubing, 1m silicon rubber tube. $60
I can be reached at:
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