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Old Nov 29, 2012, 04:12 AM
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That web page has improved, but still is off on many points. Example would be the statement that the GY240 works best with analog servo's. The GY240's performance is greatly enhanced with a good digital servo.
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Old Nov 29, 2012, 09:04 PM
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Thanks for that Roto.

What components would you recommend?
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Old Nov 30, 2012, 05:10 PM
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A digital servo perhaps?
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Old Nov 30, 2012, 08:38 PM
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To early to make specific recomendations. Would need to figure out how much torque is needed, and the speed. So the control concept would be the first step.
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Old Dec 01, 2012, 01:42 PM
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Hi Roto,

My centre canard is ~50 square inchs (12 X 4) and 100% balanced so the loading is very reasonable.

It has been suggested to me the HiTec HS-5646WP servo would be appropriate.

I have also gleaned a heading fixed gyro would be a good controller.

I am trying to determine how I could incorporate turn banking into this arrangement...

Perhaps this would dictate what components may be favourable.

Speed will be zero to 15 knots (8m/s).

Lower speeds will be managed by a kayak paddle as there is little roll stability only damping really.

Thanks for your interest.
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Old Dec 01, 2012, 01:52 PM
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I still say a MWC flight control board would be a better choice. It's very tweakable. And a lot more versatile than a gyro. http://www.goodluckbuy.com/crius-upg...r-v1-0-se.html

If you want stability, turn on the accelerometers, if you want banked turns, turn them off. Or adjust PID settings for how much hold you want. You don't even need the gyro.
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Old Dec 01, 2012, 02:14 PM
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Wow Balr, that is some piece of kit.

The learning curve is a bit steep here for me but I am keen.

Why do you feel this would be a better solution?

I'm thinking other than fly by wire, simply mounting the sensor on a tilting joy-stick may facilite turning/banking.
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Old Dec 01, 2012, 03:52 PM
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Quote:
Originally Posted by BluenosePacific View Post
Wow Balr, that is some piece of kit.

The learning curve is a bit steep here for me but I am keen.

Why do you feel this would be a better solution?

I'm thinking other than fly by wire, simply mounting the sensor on a tilting joy-stick may facilite turning/banking.
RC helicopters vary quite a bit, but they all fall within somewhat limited parameters. Since your purpose is very different, you may need to be able to adjust parameters in the control loop way beyond what helicopter gyros allow. So, ideally you need a control board that lets you adjust every possible parameter, and/or completely reprogram the software itself. There are many such boards available, and if you're hard core, you can pick up some Arduino and the proper sensors, and get some open-source software and tweak all you want. It may be difficult to find software and known parameters for operating in water.

You're going to need to establish a proper control loop, so I don't know what you mean by putting the sensor on the stick.

Have you read Gyros 101?

http://www.helifreak.com/showthread.php?t=76808 - this explains how a gyro achieves physical stabilization between the aircraft and the control signal. Keep in mind that's the goal with helicopter gyros - they are not simply damping, they are controlling too.
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Old Dec 01, 2012, 05:13 PM
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Quote:
Originally Posted by BluenosePacific View Post
Wow Balr, that is some piece of kit.

The learning curve is a bit steep here for me but I am keen.

Why do you feel this would be a better solution?

I'm thinking other than fly by wire, simply mounting the sensor on a tilting joy-stick may facilite turning/banking.
The entire purpose of accelerometers is to maintain stability based on a value established when you allow the board to initialize. If your craft deviates from those values it will react. That board also has a 3 axis gyro, a barometer and magnetometer. So the control functions you can use are quite extensive and very versatile. A gyro has very limited input/output capabilites, this board has many. These boards are used to stabilize and control most aerial camera platforms you see now. I'm pretty sure it will handle your needs. They aren't that hard to program. All that is required is picking limits in a GUI program. However, if this is beyond what skills you feel you have, a KK2 board is about as difficult as setting an alarm clock. http://www.hobbyking.com/hobbyking/s...rol_Board.html
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Old Dec 01, 2012, 05:47 PM
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Well, isn't that one of the more interesting things I've read in a while.

Thank you Jasmine2501.

Your comments are certainly thought provoking and I completely appreciate where you're coming from, well said.

I'm inclined to think I'll try and see if heli adjustment tolerances are adequate for my needs and go from there.

The idea I had with mounting the sensor (gyro) on a roll (tilt) oriented joy stick was to "fool" the gyro into allowing the vehicle to lean or bank into a turn.
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Old Dec 01, 2012, 05:48 PM
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Thanks Balr, I'll check it out.
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Old Dec 01, 2012, 07:40 PM
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Quote:
Originally Posted by BluenosePacific View Post
The idea I had with mounting the sensor (gyro) on a roll (tilt) oriented joy stick was to "fool" the gyro into allowing the vehicle to lean or bank into a turn.
That might actually work now that I think about it - IF the stick is mounted on the vehicle you're trying to stabilize. The thing with gyros is they just try to match the sensed amount of rotation to the desired amount of rotation from the control input. If the input (stick input) doesn't match the output (actual sensed rotation), the gyro creates a control signal to try to correct that situation - the vehicle's rotation must react to that control signal to close the loop.
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Old Dec 01, 2012, 08:56 PM
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You're on the right track there 2501 but I'm controlling roll here not yaw.

So take what you said and simple apply it to the other axis.
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Old Dec 02, 2012, 12:02 AM
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Yes it works on any axis.
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Old Dec 02, 2012, 12:51 AM
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Balr14, $20!! that's amazing!

2501, sorry, I thought you had misunderstood but it was I who missed you...

The board seems the way to go.

Can I set it in epoxy to waterproof it?
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