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Old Jan 29, 2013, 04:25 AM
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Zbig's Avatar
Warsaw, Poland
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Originally Posted by Tikky View Post
The "stall speed" is not single. As it depends on load factor, it is for exemple double under 4G! A simple turn with a bank of 60 increases "stall speed" by a factor of 1,4.
O course you are right! I've think of steady flight and vertical aircurrents only, but real flights are more complicated.
Different payload is natural for airliners, but in FPV payload do not changes often, so we can easily forget about this factor.
But when maneuver causes (or requires) increase of lift without changing airspeed - this extra lift can be achieved only by changing (increasing) angle of attack - it's obvious.
Factors you've given are big, so making just "safety margins" for airspeed to cover all this situations seems to make no sense.
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Old Jan 29, 2013, 01:10 PM
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France, PACA, Saint-Cannat
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Quote:
Originally Posted by Zbig View Post
Different payload is natural for airliners, but in FPV payload do not changes often, so we can easily forget about this factor. .
Well. It seems you mix up playload with g load. Anyway, let's continue on PM if you want, better talk about your fantastic OSD here
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Old Jan 29, 2013, 04:04 PM
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I'm aware about G-load - any acceleration needs force (change in lift in our case). I've mentioned payload because it changes "stall speed" in airliners too.
It's interesting topic and many hobbyist are not sure what causes stall - and thus crash of their valuable airplane. I'm sure this discussion spread some light on this subject.

And OSD will defend himself
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Last edited by Zbig; Jan 30, 2013 at 03:49 AM.
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Old Jan 30, 2013, 04:29 AM
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The reason why so many want airspeed as an indicator is because this is used in real aircrafts. Sure stall depends on many factors but if you know the airspeed it is a lot easier to prevent it during landing.

Airspeed is also very useable when flying to find out wind direction etc. This is especially important for long range rc models since our small models fly relatively slow. A little wing not even noticable in full scale can have a big impact for us.
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Old Jan 30, 2013, 05:22 AM
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Originally Posted by boopidoo View Post
Airspeed is also very useable when flying to find out wind direction etc. This is especially important for long range rc models since our small models fly relatively slow. A little wing not even noticable in full scale can have a big impact for us.
You're right. Considering that we have the airspeed it should be possible to comput wind direction and windspeed. Only one more parameter is needed: heading. There are two ways to obtain it: a magnetic sensor (compass) or via IMU calculation like in real plane like mine. I don't know if RC used IMU have enough output parameters for that.
It could be very usefull for FPV pilotes, specifically for those using gliders.
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Last edited by Tikky; Jan 30, 2013 at 05:45 AM.
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Old Jan 30, 2013, 06:26 AM
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Even if wind speed and direction isn't calculated it is quite easy to find out yourself by just making a slow turn. That was the way I checked wind speed and direction when flying full scale gliders, I compared ground speed vs IAS.
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Old Jan 30, 2013, 06:38 AM
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Originally Posted by boopidoo View Post
Even if wind speed and direction isn't calculated it is quite easy to find out yourself by just making a slow turn. That was the way I checked wind speed and direction when flying full scale gliders, I compared ground speed vs IAS.
Yes it's a way to have a good idea of it but, as it's just a matter of calculation, it's realy better to have the information display in real time front of you specifically on final
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Old Jan 30, 2013, 11:47 AM
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United States, FL, Palm Beach
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On the topic of heading and altitude hold, this weekend I got a demo of uThere Ruby autopilot, and it does perform this function. It will maintain a heading even if that means flying with a sideslip angle to achieve this in a strong wind. This is handy when self-launching a large airplane, getting it to a safe altitude and heading, setting your HOLD, then walking back to your comfy chair and FPV monitor/goggles to continue your flight. Larger, faster airplanes get out of sight rather quickly, but for slower planes you could walk to your FPV station while maintaining LOS.
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Old Jan 30, 2013, 05:46 PM
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Originally Posted by viper522 View Post
On the topic of heading and altitude hold.
This suggestion is on my shortlist for next version. I don't want to delay current BETA version, which is almost ready to manufacture.

Latest major change in this version is fully customisable, analog user input.
It can be used for analog sensor like temperature, or under water pressure for submarine boat (yes, it is real request from one of our customers) when following formula is used:

Quote:
result = scale * (ADC + offset)
Or for differential pressure sensor for airspeed measurements, when other formula is applied:

Quote:
result = scale * sqrt( ADC + offset)
this will cover this request as well:
Quote:
Originally Posted by henkvdw View Post
Can other than the EagleTree airspeed sensors be used?
APM for example?
http://store.diydrones.com/Kit_MPXV7...v7002dp-01.htm
Other formulas can be added if needed.

In any case user can define 3-letter units attached at the end of result.

User can define those parameters in convenient way:
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Last edited by Zbig; Jan 31, 2013 at 03:57 AM.
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Old Jan 31, 2013, 08:03 AM
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United States, FL, Palm Beach
Joined Jan 2011
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Very cool Zbig. I currently have DragonOSD v2 and Skylark Trace III OSD, but I only actually need one solid OSD. And with a new 50" high speed wing on the way, you might have the best offering.
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Old Feb 01, 2013, 08:20 AM
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Poland, Silesian Voivodeship, Tarnowskie Gory
Joined Feb 2012
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If the PPM signal from RC receiver is connected to the input number 6 ( Autopilot ) , is active configuration of inputs 1-5 as outputs 7-11?
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Old Feb 01, 2013, 04:27 PM
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Warsaw, Poland
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Both inputs #1 and #6 are reserved as serial inputs, for future use in diversity RC. Only inputs #2 to #5 are free to use in serial PPM mode. Present firmware do not utilise those inputs in serial mode, but it is quite possible to use it as outputs in next versions of firmware.
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Old Feb 05, 2013, 05:28 AM
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I've got information that pressure (depth) sensor for submarine boat works well with OSD user-configured input

BTW. How we should name equippment for such boat? First Captain View (FCV)
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Old Feb 07, 2013, 09:18 AM
Hitech soaring
Germany, BW, Stuttgart
Joined Jan 2013
8 Posts
OSD Video Quality

Hello

your pitlab OSD Video qualty is much better than the Feiyu OSD.
The pictures show the difference.
I thought the same when I saw my camera picture the first time last weekend.

In the pictures you can see the difference by using the same equipment except the OSD. There is much less noise on the pitlab OSD video signal.

Regards pitpilot.
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Old Feb 07, 2013, 05:19 PM
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Joined May 2012
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Nice to see this equipment on RCG. Yes, video quality is good and it supports 690tvl cameras.

I've made a short compilation of many flights with Zbig & Pitlab set. Video is rendered quite well so you can see exactly the same what pilot see.

The Best Of - Podlaskie z Lotu Ptaka 2012 part 1 - kompilacja z kilkudziesięciu godzin w powietrzu (6 min 43 sec)
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