Copilot 2 with 3GX help

[flash 56]

Hey guys, can anyone tell me if copilot works with a 3GX, I've been reading till my eyes hurt and not found an answer..I installed it on a trex 550 but it will not work, turn it on and it moves swash full left & hard back...not gonna chance flying it till I can find the prob..
Thanks.

[flash 56]

Can anyone help ?

[jperkosk]

It should work fine if you're using a separate Rx, wired in sequence as follows:
Rx --> CP2 --> 3GX
If you're using a satellite Rx on 3GX, CP2 won't work.

Assuming you have it wired and setup properly, you can't just turn it on indoors, the IR sensors will see the walls and CP2 will either fail to initialize or will provide constant cyclic input to 3GX. Cyclic input to any FBL controller is a roll/pitch rate command, so failing to detect any cyclic attitude change the fbl controller will max out the swash plate in one direction or other.

The setup of CP2 with a fbl controller is not a rocket science, but it's not trivial either. What I would do is make sure the fbl controller responds correctly with CP2 off (off meaning off and auto trim at 0) first. If you move your heli in the air and the swashplate tries to stay level you should be OK. Then I'd take off, take the bird up high and briefly flip the CP2 on and observe the reaction. If everything looks OK maybe flip it on for few seconds next, and so on...

[flash 56]

Thanks for replying,im not sure if it's got a sat receiver or not, but it does have an external box plugged into the side of the receiver that looks to be an antenna as the receiver is located inside the frame, I don't think it's an external receiver, this is a new helicopter that was built for me as a surprise so I'm not familiar with ext. receivers. Also it fly great with copilot turned off and auto trim is off too.

[jperkosk]

Never mind my comments, I since saw your other thread in flight stab forum, looks like you're using AR8000 which is an external receiver. And it normally works with the help of one satellite receiver for radio signal diversity reasons.

3GX is capable of accepting satellite receiver on its own and decoding the received signals itself, in which scenario it isn't possible to insert CP2 between receiver and FBL controller (both functions happen inside of 3GX in that case) but clearly that's not your scenario, so you should be good to go.

[sutty]

I'm not familiar with the 3GX, but I have done this with the MicroBeast FBL controller, so I imagine it is similar enough. If all things are well when it is switched off, and you were careful with the CPII set-up, in terms of directions etc, then it is likely that you will be good with it on too. If you can fly, then Jerry's suggestion to go high, and literally flick it on and off, is the best suggestion. If nothing crazy happens, then you can try it for a second of two, and then longer. When you try for longer you will likely see some drift, and this must be adjusted out in the CPII flight angles section. Do them one at a time, i.e. aileron first, and then elevator, and adjust each in small increments until you can flick the switch on and off at will without even a twitch in the air. As Jerry said, on the ground, and especially in the house, it is difficult to tell how the unit will perform as there are too many sources of heat nearby, which provides a corrective output from the CPII, and since this acts as the input source for the FBL controller, it is likely, and indeed common, for it to go hard over.

You can get a better idea if you put it in the middle of an open playing field on the ground, and stand back, so your heat signature doesn't affect the unit, and then flick the switch from off to on. If there is little swash movement here, then you are probably good to go. Also, if you go back to it with the unit whilst it is switched on, you should be able to see the swash move away from your hand as you move it towards the sensor. So if you put your hand up to it from the right, the swash should tilt to the left. This is because it is as if the heli and sensor were tilted to the right, the warmth of your hand simulating the warmth of the ground. Warm relative to the sky that is. So since it 'sees' your hand, it 'thinks' it 'sees' the ground on the right, so it applies the opposite swash, left swash, to tilt it back over to level, and away from what it 'thinks' was the ground. This of course applies in any direction. Always away from your hand.

If you have any doubts, then try to get an experienced pilot to check it out for you, but if this is not an option, then as Jerry said height is your friend, as long as you can fly a little. Sadly you can't really take off and land with the CPII switched on, especially when it is used in conjunction with an FBL controller, as any small corrective error, created by say uneven ground, in one direction or another, input into the FBL controller from the CPII, can be magnified as it continues to apply more and more throw to achieve what the CPII is asking of it. The net result being a tip over on the ground.

I hope this helps. Hopefully Jerry or others might have some other ideas too.

Cheers

Sutty

[flash 56]

Thank you Jerry & sutty for the replies, I think when the weather clears that's what I'm gonna try, I read of some who crashed as soon as it was turned on and I didn't wanna do that. Just wanted to be cautious I guess, as it was doing the same thing outside but not in a open field . I'm goning to try it at the flying field . Thanks.

[jperkosk]

Cautious is good . CP2 setup is a bit of catch 22 when you need to use it as a training aid as I did: it helps you learn to fly but it sometimes requires more flying skills than you have just to set it up. And it's even more so with FBL setup. Reminds me of all the good advise I was getting to do a pitch pump to verify a nitro engine tune-up on my first 600N and how much good it did me back when I could barely hover and a pitch pump was a guarantee of losing control of the bird

Nothing new to add on my part, I'm afraid, maybe just a remainder to make sure that both CP2 and the model in the Tx should be set to 90° 1-servo swashplate; the 120° CCPM swashplate mixing should be done in the FBL controller. Don't have any personal experience with 3GX, but I don't imagine why it should be any different. Double check 3GX instructions just to be sure.

If for any reason you don't have it so, please correct it and re-do the 3GX and CP2 setup, in that order. Make sure CP2 is completely off (with auto-trim at 0°) before doing 3GX setup, which means you'll need to run partial CP2 setup first, then 3GX setup, and final CP2 setup last. As per Nite's advise, make sure there is no D/R or expo on your Tx during CP2 setup, you can add them afterwards if necessary. Didn't 100% understand from your other post if your heli is flyable with CP2 off; if it is, you're probably good on all these points.

You can also do a field test as Sutty suggested: take your heli to the middle of flat flying field with at least 20-30m of unobstructed view in each direction and flip the CP2 on. There should be a very little if any swash movement, and if there is, it should be slow. Then move your hand towards the main sensor from different directions and the swashplate should be tilting away from your hand.

If all this is happening, you're good to take your bird up, but please remember (Sutty has stressed it as well) always to take off and land with CP2 off. Once all's adjusted a foot or two off the ground is all you will need, but for initial setup take it up at least 15-20 feet high, and flick CP2 very quickly on-off. If nothing crazy happens, you're good to adjust flight angles. Flick CP2 on for a bit longer and observe the drift. Turn CP2 off, land, adjust flight angle (always one at the time, it never saves time trying to adjust both at the same time, trust me), take off, flip CP2 on and observe the drift again. Repeat as necessary.

Good luck, and please let us know how it went

[flash 56]

thanks, Jerry. yes it fly's great with it off and its set up with 3 servos 120 degree swash. I can go and change it to one in the transmitter and redo quick setup in cp2 .
but would I not leave the 3gx as it is. I didn't see anywhere in the manual to set
copilot as 1 servo. sorry for sounding like such a newb. nightflyer has been on with me a lot also which has helped a lot to, maybe I'm getting there.

[sutty]

I think the 3GX uses Tx based mixing, but you should check as I could easily be wrong. If it is flying well when the CPII is off, and you are using Tx based mixing, then it would seem that this is correct for the 3GX. How this impacts the CPII set-up I am not clear. If you can confirm, then I will apply some thought, unless of course someone else chimes in with some more direct first hand experience of your set-up.

Cheers

Sutty

[jperkosk]

Flash, if the 3GX uses Tx based CCPM mixing (which is an exception for a FBL controller, but seems to be a case since this is how you have it setup and it flies well) then both Tx and CP2 need to be set to 3-servo @ 120°. Please double check that this is the case, though, my knowledge of 3GX is nil.

In fact in this case you wouldn't be able to use CP2 with 3GX if your heli had a different swashplate, such as 140°, as CP2 only supports 1-servo and 3-servos @ 120° swashplates.

As is, looks like you're good to go, wait for a clear weather and go to the field to do the tests; start with the stationary hand tests in the middle of the empty field