My assumption was that my video range would be the Achilles heal of my setup.. But I discovered this week that the limit of my quad (Using a DX8 and AR6210) was a paltry 400m.
This wasn't actually a problem as the quad has a FS and that kicked in and bought itself home.. But how do you go about finding the limits on a plane which does not have a FS?
Obviously you can do some kind of ground test, but thats not really going to work.. The only way seems to fly, but when you go too far, its too late.
I am currently building FPV into my WOT4 (using an Orange RX for the first time) and that will have an AP/RTH, so its not a big deal...
But for my Radian glider, I have simply got a backpack (With Camera, OSD and TX) and am only using an AR500, so how do I find my limits?
My assumption was that teh first thing I should do was setup the RX FS to zero throttle.. And then circle above me gaining hight until I loose signal.. Then the engine should cut and it should stall and drop back down into range.. But this could go wrong, if it doesn't stall and just glides out.
I also wondered if you could attenuate the TX antenna in some way.. Then when you lose control, you could just remove teh attenuation (i.e bag over aerial, point the antenna down, etc)..
Does anyone have any advice on how you go about this? Or is it simply that if you don't have FS/RTH you should not exceed LOS limits?
Any support/advice would be greatly appreciated
Jon
Sort answer, ground tests. ;D They do work well.
Set the fail safe to zero throttle, either level so it just glides down, or with a light turn so it circles down and maybe back into range.
We have been out to over 1.5km on Spektrum Dx8 and AR8000 on a quad. You should get at least 1km range.
Also make sure you are using DSMX not DSM2. Don't understand why you would want to cheap out on a Rx. Why risk £100s of stuff for a few more £.
Why the comment re DSM2, is it shorter range? The reason I ask is that I use a module in my old 9XII and wondered if there may be range issues?
Quote from: Ratty on July 26, 2014, 12:25:13 PM
Also make sure you are using DSMX not DSM2. Don't understand why you would want to cheap out on a Rx. Why risk £100s of stuff for a few more £.
What do you mean by "cheap" RX? Are you referring to my choice of an Orange on my WOT4?
Believe me, i didnt intend too.. But after a length debate with other members of the forum i wae convinced that it was a good product, comparible to the genuine spektrum RX.
I think i just need to realign my expectations of range.. Instead of assuming i could go miles, i am just gong to stick "local" and enjoy it for what it is...
Someone already told you what I'm going to because it's the best solution:
Get a Frsky telemetry module for £30, a Frsky D8RII receiver for £25 and a Turnigy 9x/9xr for £30-50 ... you'll have an instant 1-3km control range, with telemetry that warns you via beeps that get progressively quicker as you go out of range so you get a chance to turn back.
If you want to go further, grab a patch antenna for the Frsky module which should in theory double your range again straight out front.
Further still, the 9x/9xr will accept a UHF module.
Honestly, it's worth the investment.
Additionally, maybe your range issues could be ironed out with a better setup? Would be interested to see pics of how you have things laid out on the quad .. I'd expect more than 400m control range from a well setup system (even if it is Spektrum).
On a Turnigy 9x with DJT module and dipole antennas I've done 2.8km.
They are both right, if you want long range you will have to change control systems. However, you should be getting further than 400m with any radio. Id be interested to see your layout too.
Yes I did mean about the orange Rx, although they have been tested and I know people use them and they work fine, I still don't see the point in cheaping out on one of the most important components.
DSMX is the newer version and has better range and link quality than DSM2. I have never seen both systems tested side by side tho, its just what I, and other have experienced. ;D
Quote from: Ratty on July 27, 2014, 08:31:15 AM
They are both right, if you want long range you will have to change control systems. However, you should be getting further than 400m with any radio. Id be interested to see your layout too.
Yes I did mean about the orange Rx, although they have been tested and I know people use them and they work fine, I still don't see the point in cheaping out on one of the most important components.
DSMX is the newer version and has better range and link quality than DSM2. I have never seen both systems tested side by side tho, its just what I, and other have experienced. ;D
I will upload some photos tomorrow. But i have just finished my FPV "backpack" which means i am ready to fly my Radian (with an AR500) so will be interested to see what range i fan get with that.
One thing i do wonder if its significant. My AR6210 antennas are not straight. The one on the RX is horizontal but it tends to bend up.. And the satellite is mounted with the antennas vertical but those wires are bent too and tend to fold back.
I wonder how important it is to get them "straight"? I am considering adding some "tubes" to make them rigid.
I am also going to do a range test this week (reduced power) and am going to go right to the limit to see how far i can walk away before i loose signal...
Was thinking today about the suggestion of putting a bit of left/right stick in on failsafe to get the plane to circle.. But my RX only supports throttle in FS.
So I wondered, is it bad form to setup the rudder (this is effectively the aileron on the Radian) so that its always pointing a bit left/right.. And then using sub-trim to put it straight.. That way, when if FS kicks in, the controls will go back to Zero which will then give me a bit of rudder and get it circling.. Is it bad form to do this?
Jon
My honest feeling. Get a better radio :)
By UK law, your throttle should always cut if you loose signal. This is for safety. Last thing you want is a motor driving your model full speed into somebody!
Quote from: rob.thomson on July 28, 2014, 02:25:16 PM
My honest feeling. Get a better radio :)
By UK law, your throttle should always cut if you loose signal. This is for safety. Last thing you want is a motor driving your model full speed into somebody!
Motor Cutting isn't open to debate.. Thats a given and thats how I have it set up. But I want to put in a bit of left/right stick so that it circles, so rather than buy a new RX, I was just wondering if I could achieve the same with "Sub Trim"
There is no doubt that changing the radio could solve some of my problems.. But to be honest, this whole range thing makes me nervous and I am more than happy to stick 'local' and fly around in a 400m radius.. But I just wondered if anyone had any tips on how to find your limits, without loosing the plane for good..
And it seems that zero throttle and a bit of rudder would work as it would allow it to circle slowly down giving me time to move towards it a few meters to gain control again!
you can't put in a bit of "left / right stick". .. if you do, it'll be like giving it continuous left/right stick, so it'll not circle, it'll keep banking until it's inverted... sort of like a slow roll.
You definitely could trim a glider like a radian to fly in a circle. It effectively has dihedral so it'll want to stay the right way up.
Quote from: Steve W on July 28, 2014, 03:00:57 PM
you can't put in a bit of "left / right stick". .. if you do, it'll be like giving it continuous left/right stick, so it'll not circle, it'll keep banking until it's inverted... sort of like a slow roll.
Its the rudder.. Its a 3 channel radian and thats the only left/right control it has, so you can stick a bit of left and it keeps turning. If you go to far, it will start to role, but a few degrees seems to hold/circle.
I am going to do some tests tonight, just to be sure by dialling in a bit of trim to see how much I can get away with.. But in principal, is it bad form to set the rudder off center, and then using sub-trim to bring it back?
Jon
Yeah your Radian will turn nicely with a bit of rudder.
And it makes no difference whether your Rudder is off-centre and only centred by sub-trim, that's the point of sub-trim.
Sounds like a decent way to make sure your plane goes throttle off and then begins a slow turn.
I'm not sure that RX is going to do what you think it'll do, though. I think it might hold the last command on all the other channels except the throttle which you can set. Just do a quick test by holding the stick in the corner and switching it off. When it's still on the ground, obv. :D
The failsafe is set when you bind. So you need to mechanically put a little bit of rudder in when the servo is centred, then trim it out for level flight.
Or you can try and bind it with a little bit of rudder in.
Quote from: Ratty on July 28, 2014, 04:11:12 PM
The failsafe is set when you bind. So you need to mechanically put a little bit of rudder in when the servo is centred, then trim it out for level flight.
Or you can try and bind it with a little bit of rudder in.
My TX only remembers "Throttle".. In a FS condition, the rest of the channels just get no PPM, so they SHOULD go back to zero..
So tonight I am going to fly, and 'trim' the plane until it flys in a nice big circle.. And will then move the servo position (mechnically) so that this is the zero position.. Hopefully this will work, and then when I go out of range, it should cut the motor and start a nice gradual turn, hopefully bringing it back into range!
Jon
if its only throttle failsafe and your mechanically flying straight,loss of signal will remember last stick positions and carry on flying straight,if I remember my basics on rx,s
Quote from: Brod on July 28, 2014, 04:47:48 PM
if its only throttle failsafe and your mechanically flying straight,loss of signal will remember last stick positions and carry on flying straight,if I remember my basics on rx,s
Hmmm.. I can't say you are wrong, as I don't know.. The instructions say that it just stops sending PPM out to the other channels, so my assumption is that this would make the servos go back to zero.. But I could easily be wrong.
Looks like I had better do some tests later before I start messing around with my throws... Cheers for that.. I hope you are wrong, but if you arnt' then its saved me some work!
Jon
On my orange receivers they power up to centre position without the tx powered up so I assume when it losses signal all channels are zero'd
on the odd occasion when I have flown out of range I always think I am lucky that it returns to level flight but in reality its probably because all the servos centre :)
Ah - dihedral and rudder changes everything I said, I thought you meant ailerons.. I foresaw a crater :D
I can't help but feel you're fighting a losing battle though :) It may be worth seriously considering investing in some "proper" kit for this purpose, i.e. the FrSky gear .. it has decent failsafe on all channels, audible telemetry so you can't run out of range very easily .. and not to mention it'll give you a very nice range boost to alleviate the strain on your nervous system :)
Please also remember - what if you lose RC connection while flying inverted or in a sharp turn :P
Quote from: Steve W on July 28, 2014, 05:46:49 PM
Please also remember - what if you lose RC connection while flying inverted or in a sharp turn :P
:) Radian. "Inverted"? Would like to see that....
Edit: Looks like its possible:
https://www.youtube.com/watch?v=TmIjGHQQBB0 (https://www.youtube.com/watch?v=TmIjGHQQBB0)
But lets not get this out of proportion.. What I am doing no different to what am doing now (LOS) and have done before countless times.. I just wanted to check my range.. There is little chance that i am going to exceed it.. But just wanted to find out waht my limits were.
The servos will return to centre on failsafe. Easy to check, just turn it all on, hold rudder to one side then turn off the Tx, youll see the rudder centre.
Quote from: Ratty on July 28, 2014, 07:52:10 PM
The servos will return to centre on failsafe. Easy to check, just turn it all on, hold rudder to one side then turn off the Tx, youll see the rudder centre.
Unfortunately, I was wrong.. As others have said above, the Servos just stop where they are when you power off the TX!
The AR500 has a throttle FS so it cuts teh throttle to what ever I set it to when I bound it.. But the rest of the controls just freeze where they are.. I am gutted as I expected them to atleast level out, but apparently not!
On the range front, I tested my Radian tonight in Low Power mode on the TX and I can get 90m..
I did the same on my quad (with an AR8000) which gave me 400m last week, and also got 90m.. But at one point I left my TX 50m from the quad (on full power) and when I went back, the orange LED on the RX was flickering.. Not sure what this means, but it doesn't look good.. So I am going to have to get a friend to help me and do some tests!
Jon
Jon
Hmm, just checked my AR500 too, and it also stays where you lose connection. That's a pain.
Maybe get another Rx that has a better FS. Otherwise its guna be a painfull failsafe.
The AR500 isn't a proper full range Rx anyway. Its a parkflyer with an extended antenna. I have flown mine til the plane was tiny tho, so they do have decent range.
I plan to use these for FPV IF they ever come back in stock...
http://www.hobbyking.co.uk/hobbyking/store/uh_viewItem.asp?idproduct=45177 (http://www.hobbyking.co.uk/hobbyking/store/uh_viewItem.asp?idproduct=45177)
It has fail safe on all channels and only 8 quid... Lovely Jubbly.. You know it makes sense ;D
Obviously posting the link will result in less stock lol but I can wait my time... still lots to do before I need full range for FPV ;)
Quote from: RaySky on July 28, 2014, 10:15:44 PM
I plan to use these for FPV IF they ever come back in stock...
http://www.hobbyking.co.uk/hobbyking/store/uh_viewItem.asp?idproduct=45177 (http://www.hobbyking.co.uk/hobbyking/store/uh_viewItem.asp?idproduct=45177)
It has fail safe on all channels and only 8 quid... Lovely Jubbly.. You know it makes sense ;D
Obviously posting the link will result in less stock lol but I can wait my time... still lots to do before I need full range for FPV ;)
I think you are right.. My limited FS capabilities could be a problem.. Last night I took the Radian for a quick flight, to test my Rezembi.. I was amazed how quickly I got 300m out.. And it made me realise that the last time I flew it FPV (with no camera), I must have flown 500-700m out, just because of the time that I traveled in each direction.. And I had no problems with range then.
But after my problems with my Quad last week, I am now paranoid that the Radian will just fly off into the sunset.. So I am certainly going to pick up one of those receivers so that I have more FS options.
Let night I managed to do another range test.. I am not sure how scientific it was, but it certainly showed something.. I put the TX in my car (on the drive) transmitting on full power and then took a bare AR500 with battery and walked down the street.. I got to the end of the road (blocked by trees and houses) before the LED went out.
Whilst I was in this location, I fiddled with the antenna wires and the conclusion is that their orientation/layout makes absolutely no difference.. Whether I stretched the wire out straight, folded it up, or screwed it into a bundle, it made no difference.
Then I took my Radian (with another AR500) installed, and in the same test got exactly the same distance (or perhaps a bit further).. Then I did the same with the quad (using an AR8000) and again, got to exactly the same point.
So I don't know what conclusion I can draw from this, but to my mind, the 'range' of each of the 3 RX's i tried was pretty much the same..
Jon