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Updated: 13 hours 49 min ago

Hang gliding Videos :: RE: 1-axis gimbal footage?

27 May, 2017 - 01:57
Author: DMarley
Subject: Re: 1-axis gimbal footage?
Posted: Fri May 26, 2017 5:57 pm (GMT -8)

red wrote: dbotos wrote: red wrote: How high is the voltage that you feed to the servo? Red,
Just 5 VDC from the Arduino so far. The servo can take 4.4 to 6.6 VDC. Guess I could see if a higher voltage supply for the servo would help.
David David,

I would suggest using a straight 5Vdc from the power source, with only the signal voltage coming from the gadget. An oscilloscope might show that servo signals are dragging down the power to the servo, as is now. This power issue may or may not be causing some jitter at the "level" spot.

In RC aircraft, constant "corrections" by the servo can drain the batteries. I used a three-pin voltage regulator chip, 11Vdc in and 5Vdc 2A output, to stop that jitter. It was similar to this part, but feel free to innovate. US$.68 each.
https://www.digikey.com/product-detail/en/stmicroelectronics/L78S05CV/497-1468-5-ND/585989

For the chip I used, the regulated voltage would "float" upwards, no load, but a small-load (high resistance) resistor would hold the 5Vdc steady, when there was no other load.


Yes!

What I would try first is to provide 2s voltage (~8.2 v) to the processor and imu (the arduino uno can accept 7-12 vdc) and another battery supplying the servo with whatever it requires, but connect both battery grounds together. If that helps solve most of the problems, then provide a stepper or linear voltage reg to one battery to power the servo.... or just get a high-voltage servo. As is now the servo is most likely drawing down the voltage to the processors and creating a sort of ripple.

Hang gliding Videos :: RE: 1-axis gimbal footage?

27 May, 2017 - 01:37
Author: DMarley
Posted: Fri May 26, 2017 5:37 pm (GMT -8)

Dave,
Using arduino ide delays to attempt to correct problems just creates more problems and prevents the processor from doing things efficiently. Instead of delays, try to do a moving average calc to smooth out the outputs from the imu. Graph your inputs vs averaged inputs vs time and see what works that way. The raw inputs are probably scattered a bit. You'll have to find a running average set length that will provide reasonably smooth curves yet yield fast enough response rate. That is if putting the servo on it's own power supply doesn't correct the problem.
Try using the Atmel Studio IDE rather than the arduino ide. You'll be glad that you did later on if you make the switch. It's not the easiest to print things, but it has a much better debugger, and the whole of the ide is professional and lightyears beyond arduino's poor attempt.
You may find that wrapping the servo wires around a torus ring a few times may help reduce signal interference.

All I want for Christmas is my two front teeth .... oscilloscope and a logic analyzer!

Hang gliding general :: RE: Can anybody identify this wing

27 May, 2017 - 00:30
Author: lizzard
Posted: Fri May 26, 2017 4:30 pm (GMT -8)

Thanks here are a few more pics

Hang gliding general :: Jerry Lanham, early HG pilot in the Maryland area, dies

27 May, 2017 - 00:28
Author: jlatorre
Subject: Jerry Lanham, early HG pilot in the Maryland area, dies
Posted: Fri May 26, 2017 4:28 pm (GMT -8)

I heard recently from Richard Hays, of the Maryland Hang Gliding Association, that Jerry Lanham of Sail Flight Systems has passed away. He hadn't been active in the sport for over thirty years or so, but back in the day he was one of the pioneers of the sport in the D.C./Maryland/Virginia area. His company, Sail Flight Systems, taught a lot of people to fly. Red Howard probably remembers him, since he was a common sight at Oregon Ridge.

He also was a manufacturer for a while in the 1970s, making your basic Dickenson wings (aka "Standard Rogallos") and then clones of the Cirrus 2. His quality control was often erratic, and his students often came away with sprained ankles and such. I was an instructor at a rival school that shared the training site at Oregon Ridge with him, and I often ended up driving those students to the nearest hospital. (I still remember when I checked one student in. The admitting nurse took down the pertinent information ... type of injury, where it happened, etc. When he told her that it happened during a hang gliding lesson at Oregon Ridge, she looked up and said, "You should have pushed out!")
_________________
"Good judgment is the product of experience. Experience is the product of bad judgment."

-- old aviation proverb

Hang gliding general :: RE: Can anybody identify this wing

27 May, 2017 - 00:18
Author: jlatorre
Posted: Fri May 26, 2017 4:18 pm (GMT -8)

DVH is Deutscher Hanggleiter Verein (German Hanggliding Association), which was the certifying agency for most European gliders.

My German is pretty rusty, but I could probably interpret the plate for you. My guess, though, is that it could be any of several Atlas clones that were made between 1979 and 1985.
_________________
"Good judgment is the product of experience. Experience is the product of bad judgment."

-- old aviation proverb

Hang gliding general :: RE: Can anybody identify this wing

26 May, 2017 - 23:53
Author: kukailimoku
Posted: Fri May 26, 2017 3:53 pm (GMT -8)

Could you add close-ups of downtube/basetube and crossbar junctions?

There are a few designs that looked a lot like that...
_________________
In the event of decompression oxygen masks will deploy from the the ceiling above your seat.

Untangling them will annoy you as you lose consciousness.

Hang gliding general :: Can anybody identify this wing

26 May, 2017 - 23:47
Author: lizzard
Subject: Can anybody identify this wing
Posted: Fri May 26, 2017 3:47 pm (GMT -8)

Hi Everyone,
I am looking at buying this glider .
The owner does not know its pedigree but it has a plate on the xbar with DHV ,a list of speeds as usual but no numbers ..other than the brand DHV the language is German I think . The owner says its a 170 sqft which makes it attractive to me for a dune wing.

Thanks

Lindsay

Hang gliding general :: RE: Computer Simulation of a Hang Glider

26 May, 2017 - 20:23
Author: Watson
Posted: Fri May 26, 2017 12:23 pm (GMT -8)

Hi Steve,

You just gave an amazing idea!

I'm currently running with a inlet boundary condition that changes in order to balance the weight of the glider + pilot with the lift, so basically it speeds up and down in order to find equilibrium at a certain AoA.

Now, from what you are saying, I think that I can include the entire glider and change the inlet flow angle depending on the forces on either side of the glider. This way the yaw-roll oscillations might be simulated by just changing the boundary conditions, rather than making the glider move.

Of course, a good FSI would be needed to include all the correct physics, but it looks possible!

Thanks for the input,
Watson.

Hang gliding Videos :: RE: 1-axis gimbal footage?

26 May, 2017 - 20:19
Author: red
Subject: Re: 1-axis gimbal footage?
Posted: Fri May 26, 2017 12:19 pm (GMT -8)

dbotos wrote: Red,
Quickie research yielded the following current draws for the three components:
So I could be getting close to if not exceeding the 500 mA standard for USB. Powering the servo from its own supply sounds like a good way to eliminate possible voltage drag-down. I'll ultimately need a battery that will run all the gimbal components. And maybe voltage regulator like you mentioned depending on how the battery and component voltages work out. I'll have to remember about small load resistor to keep output properly regulated. Thanks,
David David,

Everybody in your game needs an Oscilloscope. Here is a DIY oscilloscope that uses your PC sound card, and a few extra pieces. The guy mentions Hantek, if you want an off-the-shelf commercial solution, still much cheaper than a fer-real commercial oscilloscope. Have fun . . .

http://homediyelectronics.com/projects/howtomakeafreesoundcardpcoscilloscope/
-
_________________
Cheers,
........Red.........................
Pssst! New pilot? Free advice, maybe worth the price,
http://www.xmission.com/~red/
H4, Moyes X2, Falcon Tandem, HES Tracer, Quantum 'chute

Hang gliding Videos :: RE: 1-axis gimbal footage?

26 May, 2017 - 17:17
Author: dbotos
Posted: Fri May 26, 2017 9:17 am (GMT -8)

Check out this guy's stepper-driven balancing robot:

http://www.brokking.net/yabr_main.html

It uses NEMA 14 steppers, DRV8825 driver boards, and an 11.1V 2200 mAh RC battery. Couldn't find mention of battery life, which is one of my worries with steppers. Listed battery weighs ~6.2 oz. My current statically mounted camera setup (mount + camera + waterproof case) weighs 10.4 oz. What would be the max weight you think I could safely stick on the keel of my Falcon 3 195 just behind the neoprene sleeve that covers up the rear wire attachment point? I guess the gimbal battery could be located further up on the keel so it doesn't cause as much of a pitch moment.

Hang gliding general :: RE: Hang glider pilots learn to spel

26 May, 2017 - 17:05
Author: Nigel Hewitt
Posted: Fri May 26, 2017 9:05 am (GMT -8)

RobertKesselring wrote: I can't tell if you're being serious or speaking in jest.
If you're being serious, I disagree. I know several people who are extremely intelligent and well educated who have less than perfect English. For some of them, English is a 2'nd or 3'rd language. For others, it's just not their strong area. Being able to correctly use a semicolon does not make someone smarter than someone else who can correctly use tensor calculus.
ROTFL.
I have a distinctive regional accent and people seem to think it marks me out as intelligent. I know that they're kidding themselves. I was just born at Oxford in the UK.

Conversely, having now retired, I haven't had to do tensor mathematics for years. I don't miss compressible flows and such evils one bit. I used to be paid to think so I'm darned if I'm thinking on my own time.
_________________
nigelH
Avian Rio 15, Aeros Target and Aeros Phantom
Waterboarding at Guantanamo Bay sounded like a radical holiday opportunity until I looked it up.

Hang gliding Videos :: RE: 1-axis gimbal footage?

26 May, 2017 - 17:01
Author: dbotos
Posted: Fri May 26, 2017 9:01 am (GMT -8)

I checked out the sensitivity of one of the level vials in both directions with my digital level. Here are the results:

0° --> bubble centered
0.5° --> end of bubble almost touching black line
1.0° --> small portion of bubble over the line
1.2-1.3° --> bubble takes off and heads to end of vial, almost like you had a flat-topped hill and pushed at ball to the point where the flat meets the slope

Hang gliding Videos :: RE: 1-axis gimbal footage?

26 May, 2017 - 16:46
Author: dbotos
Posted: Fri May 26, 2017 8:46 am (GMT -8)

Red,

Quickie research yielded the following current draws for the three components:

Arduino Uno R3: ~50 mA in idle state
GY-521 IMU: probably in the neighborhood of 5 mA
MG90s servo: 230 mA idle; 300-460 mA for 1 - 1.6 kg-cm of torque

So I could be getting close to if not exceeding the 500 mA standard for USB. Powering the servo from its own supply sounds like a good way to eliminate possible voltage drag-down. I'll ultimately need a battery that will run all the gimbal components. And maybe voltage regulator like you mentioned depending on how the battery and component voltages work out. I'll have to remember about small load resistor to keep output properly regulated.

Thanks,
David

Hang gliding general :: RE: Hang glider pilots learn to spel

26 May, 2017 - 09:32
Author: RobertKesselring
Posted: Fri May 26, 2017 1:32 am (GMT -8)

Comet.
I can't tell if you're being serious or speaking in jest.
If you're being serious, I disagree. I know several people who are extremely intelligent and well educated who have less than perfect English. For some of them, English is a 2'nd or 3'rd language. For others, it's just not their strong area. Being able to correctly use a semicolon does not make someone smarter than someone else who can correctly use tensor calculus.
_________________
Do something today to inspire a new pilot for tomorrow!

Hang gliding general :: RE: Hang glider pilots learn to spel

26 May, 2017 - 08:19
Author: Comet
Posted: Fri May 26, 2017 12:19 am (GMT -8)

Don't sweat it Steve: spelling and grammar are how we can immediately distinguish if someone's opinions are valid or not.

If someone has good language skills, chances are that they have some intellect and education behind their views. If not, then we can probably dismiss their rant as originating from a position of ignorance. But if you get them all to correct themselves, how can we tell who is who?

U knoe, becuz spellin is like hard and shiit...

Hang gliding general :: RE: Hang glider pilots learn to spel

26 May, 2017 - 03:36
Author: AIRTHUG
Posted: Thu May 25, 2017 7:36 pm (GMT -8)


Link

_________________
Shut up and fly.

Hang gliding general :: RE: Hang glider pilots learn to spel

26 May, 2017 - 03:19
Author: Rick M
Posted: Thu May 25, 2017 7:19 pm (GMT -8)

This sums it up nicely:

http://theoatmeal.com/comics/misspelling
_________________
Rick
Hang 3 - WW U2 160
FL - ST - FSL - AT - TUR

"Once you have flown you will walk the earth with your eyes turned skyward, for there you have been, and there you long to return" -- Leonardo da Vinci

Hang gliding general :: Hang glider pilots learn to spel

26 May, 2017 - 02:33
Author: aeroexperiments
Subject: Hang glider pilots learn to spel
Posted: Thu May 25, 2017 6:33 pm (GMT -8)

"you have 4 breaks and 1 clutch"

breaks= brakes
fleg = fledge

To be updated... add your own

Hang gliding Videos :: RE: 1-axis gimbal footage?

26 May, 2017 - 01:45
Author: red
Subject: Re: 1-axis gimbal footage?
Posted: Thu May 25, 2017 5:45 pm (GMT -8)

dbotos wrote: red wrote: How high is the voltage that you feed to the servo? Red,
Just 5 VDC from the Arduino so far. The servo can take 4.4 to 6.6 VDC. Guess I could see if a higher voltage supply for the servo would help.
David David,

I would suggest using a straight 5Vdc from the power source, with only the signal voltage coming from the gadget. An oscilloscope might show that servo signals are dragging down the power to the servo, as is now. This power issue may or may not be causing some jitter at the "level" spot.

In RC aircraft, constant "corrections" by the servo can drain the batteries. I used a three-pin voltage regulator chip, 11Vdc in and 5Vdc 2A output, to stop that jitter. It was similar to this part, but feel free to innovate. US$.68 each.
https://www.digikey.com/product-detail/en/stmicroelectronics/L78S05CV/497-1468-5-ND/585989

For the chip I used, the regulated voltage would "float" upwards, no load, but a small-load (high resistance) resistor would hold the 5Vdc steady, when there was no other load.


_________________
Cheers,
........Red.........................
Pssst! New pilot? Free advice, maybe worth the price,
http://www.xmission.com/~red/
H4, Moyes X2, Falcon Tandem, HES Tracer, Quantum 'chute

Hang gliding general :: RE: prius as glider car

26 May, 2017 - 01:34
Author: aeroexperiments
Subject: Re: prius as glider car
Posted: Thu May 25, 2017 5:34 pm (GMT -8)

red wrote:

Man, that will be some hefty overhang lengths, both front and rear. Better check with the local LEOs about what your legal limits will be there, for overhang lengths.

The only time I was ever pulled over for this, it was the front end they were worried about. Apparently in Oregon there is maximum amount that something can project forward of the front bumper. In this instance I was just barely within the limit. But (oops!) I can't remember if the glider on my car was a curved-tip glider or something longer like my Falcon 170.

On a Ford Festiva w/ a ladder rack.

Steve