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I already have the chart from ground level UP. Its easier than it sounds.

Its true that at times the horizon indicator would indicate level when the craft wasn't but I don't need to read a LOOP, just know if the nose is up or down in level flight. It needs to be better than a glass of water on the dash but I want to try easier ways before using mult axis gyro's. :D Also keep in mind, I can usually see the horizon, a mark on the monitor sides where the sky meets the ground might be just fine.

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as you pull up/turn your exert g forces in the direction opposite of your turn, therefore a glass of water on the nose will be perfectly flat as you pull up, and an accelerometer would read pulling up as flying flat. Try it with a shopping bag with water on it.. spin the bag around your head :D

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59.95 is what I am seeing.

I'm still looking for cheaper solutions.

a mark on the monitor sides where the sky meets the ground might be just fine.
Edited by ddwaner
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The weight will only work correctly when your lateral acceleration is zero. So, if you're accelerating forward, your weight will suggest that you are nose up even though you're actually level. It's these sort of stuff that limits the usefulness of that scheme, simple as it may be. And since you don't know your lateral acceleration, you can't compensate for the error.

Daniel

Edited by Daniel Wee
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So it's not gonna read right when I'm do'in a loop (course I won't spill any water out of a glass either).

So if my lateral acceleration is NOT Zero and the screen is showing a big change in direction, I should NOT be looking at the artificial horizon. I should be looking at the monitor and trying to get back to smooth flying (GOOD IDEA!).

Edited by ddwaner
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So just read the altitude and generate a psudo horizon that would indicate climb, fall or level compared to the last altitude sample. Hmmm... Wouldn't need a servo just a linear IC and 3 LED's. That would be only 1 device in the aircraft and would be lighter and cheaper than 2 devices in the aircraft and acceleration/deceleraton/GForce would be less a factor and I could use the second audio channel for something else (like receiver signal strength) 3 values from 2 audio channels!

Edited by ddwaner
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I don't think you understand what I am saying:- Let's say your plane is flying level and straight at a constant velocity - at this point your weight will be directly pointing downwards, as you would expect it to. But now, if you hit the throttle, but maintaining level flight, your plane will start to accelerate (but not climb or descend) - at this point, your weight will move to indicate (falsely) that you are climbing when you are in fact still level. Now, still keeping level flight you throttle down, your plane decelerates but stays level since no elevator has been applied (assuming your planed has been trimmed properly) - at this point your weight sensor will indicate (falsely) that you are diving.

All this while you are in level flight, neither climbing nor descending, but due to the acceleration and deceleration, your weight sensor will give false readings. I don't know if I can be clearer than this.

Daniel

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So if the Altitude is 500 feet and 3 seconds later the altitude is read and it is now 510 feet. Did the aircraft Climb/Fall/OR Stay Level the last 3 seconds. Would you say Climb!!! Now decide what the trigger threshold will be. Maybe add 2 more LED so if the value is greater than 20 another LED would light till the next sample.

Edited by ddwaner
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Let me try again:-

POINT A

Altitude: 500 ft

Speed: 50 ft/s

Acceleration: 0 ft/s2

In this state, your device will work. But now:-

POINT B

Altitude: 500 ft (no change at all) <------------------- NO CHANGE

Speed: went from 50 ft/s to 70 ft/s in 10 seconds

Acceleration: 2 ft/s2

Now, would you agree that because there is no change in altitude, your device should have stayed level? Thus it SHOULD not indicate any change since the plane has not changed it's attitude at all. The only thing that has changed is the speed and acceleration.

In this condition, your device will NOT remain unchanged. It will in fact indicate falsely that you are climbing when you are not climbing. I hope you realize we're not talking about the altitude sensor here but the attitude sensor (a.k.a. artificial horizon).

Daniel

Edited by Daniel Wee
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If you don't change the altitude then the horizon is still level using the pressure sensor from the altitude downlink.

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Yes but I was referring to your earlier proposal to use a potentiometer with a weight attached to be used as an attitude sensor. What I've been saying is that such an arrangement is unreliable and will yield false readings. When you're looking through the video, you have no idea if you are accelerating, or decelerating, or even staying at constant speed. Furthermore, unless your actual horizon is perfectly level (ie. calibrated) it will be hard to tell if you are climbing or diving (except for large changes).

So, if your plane was climbing at, say 3-meters a minute (0.05m per second), with a slightly nose up attitude, you can't really tell that from just looking at the video alone. Then suppose that at the same time you are slowing down due to a headwind. Again, you won't realize anything from the video alone. Now, in this type of situation, that weight+potentiometer device is going to yield unpredictable results. The end result is that you won't know if your plane was climbing or descending, either from that said device or from the video. You can tell the altitude change from a separate pressure sensor, but you won't know if you are climbing due to a thermal or due to a change in attitude, or due to a change in airspeed.

Of course, if all you want is a very crude device such as the ball (as Kilrah referred to) to indicate perceived downwards vector, that's probably okay but remember, it won't be telling you the attitude exactly. If you flew into a fog or cloud, basically that weight+potentiometer instrument is not going to be very good in terms of telling you your attitude. This applies to both pitch and roll. Then again, if you're going to be relying on video most of the time, why have such a device, especially if it won't be able to tell you the attitude reliably when you most need it?

Daniel

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The derived horizon from the altitude changes would do just fine at about 1 to 3 second intervals. If the aircraft lost altitude in the last 3 seconds then its falling which would be what I want to know. It hard to pick the aircraft out of the top of some of the tree's so the numeric of the altitude would be the most important.

I still don't have problems with the plumb bob method, it would probably tell me what I wanted to know but if I can omit the device and derive the value with the other existing devices in the aircraft, so much the better,... and it would work better!!!

Edited by ddwaner
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When it comes down to building the aircraft and transmitter and reciever and ground setup and recording and editing and web site establishment and developement with FTP, I have been for the most part "ON MY OWN". I couldn't even get a ready made 2.4 TX/RX combination so I had to fabricate from parts. My 25 years in industrial automation electronics and instrumentation may help a little (I was kind of a Rocket Scientist too(I did Industrial Combustion Work for years)).

Today's ground RIG.

post-6-1182909586_thumb.jpg

Edited by ddwaner
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Got 3 flights. I found that with 3 Spektrum transmitters running I had a better picture when I went from channel 2 to 4. I made 1 landing from the monitor. The Airwave TX/RX combo transmits the audio from the camera module good an clear. I still had some dropouts which I will work on with RX placement, today I just did it the EASY WAY. From the 10mw TX/RX combo I was using to the one I have now, I have decreased the number of dropouts by about 70%.

P.S.

I must have taken the last two pictures with the camera in the low light mode in full daylight, or it was in Macro mode.... Oh well I got a snap of the rig (today).

ONCE AGAIN

The main part of this experiment is a "GOOD CHAIR"

:rolleyes:

post-6-1182910004_thumb.jpg

Edited by ddwaner
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Had bad weather today so I experimented with smoothing out the roll with wind. I used a old piezo gyro that I used on my Shogun Heli and placed it on the aileron channel and went back to the OLD way when using two aileron servos using a Y harness. I first set the gain on the gyro HIGH but found that the airplane was so ROCK solid on aileron that I would not have been able to do GOOD aerobatics. I ended up using about the same gain as I used on small helicopters like the Shogun or T-Rex (tail ctrl). The gyro cost about $55 new and has always done well for the money. It is mounted outside of the aircraft today because it does not have remote gain adjustments, also, the gain adjustment effects center so now that I have the gyro gain how I want it, I will fix it inside the aircraft.

When my camera plane is complete I expect to use this gyro on elevator and a Futaba 240 on aileron for aircraft/camera stability (but that means I have to take my 240 off my T-Rex and buy a new Futaba 401 to go back on my T-Rex, OH WELL..). :D

I also built a NiMh 6 cell 1100 battery for the receiver. When using the battery, the regulator seems to run cooler and the battery should be able to run about 5 or 6 hours on a charge with the receiver.

post-6-1182992233_thumb.jpg

Edited by ddwaner
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Anyone interested... This is the field I most often fly. Its about 5 minutes from where I live. :wub:

The full view High Res Pic is here... http://rcflyerscu.hobby-site.org/RemotePic...nways_zoom3.jpg

post-6-1183019870_thumb.jpg

Edited by ddwaner
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Could one get attitude information using 3 axes of electronic compasses? Perhaps wouldn't be so vulnerable to effects of acceleration as a gyro (or a plum bob).

Never heard of anyone trying this, mind.

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It should be possible to do something with that too, but it will be a pain to get it working especially on electric aircraft. According to a friend's tests it's a nightmare to get a compass to work well on there due to the high and variable currents running in the power wires.

Edited by Kilrah
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As long as YOUR buy'N. $250.00 is a bit price'E, I'd more use the little compass ball in front of the camera for about a dollar. For $250 I could build a second video feed setup and send just the instrument panel (including compass ball) to the ground and still make change.

:P One of the advantages of ELECTRIC aircraft is that you don't have to clean the camera lenses as often and they almost NEVER start backwards.

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