DX7 setup with 250 help required please!!

[AlasdairM]

OK - I have been hovering and gentle forward flight and lazy eights for a couple of months or so now (Blade 400 and Trex 500) - with DX6i and got used to how to change things on this.

Have now treated myself to DX7 and a 250 (SuperCombo so using Align stock gyro and DS410/420 servos).

250 is built but am having huge problems with how to sort out the sensitivity of the gyro - especially how to use or change settings so that Gear switch flips between HH and Rate mode AND at the same time being able to change gyro %'ges.

Used to be able to do this standing on my head with the DX6i, but as this was "traded-in" for the DX7 I am badly lost!!

ESC is correctly set up (I think!), and tail servo is at 90 degrees with tail blades in center of tail rotor etc. when servo centred. Swash is level etc. and mechanically I think it is OK.

When spooling up, as soon as any change to rudder happens, either by me on rudder stick, or the gyro, the tail spins fast - I have checked the rudder servo direction (on DX7) and also the gyro direction (on the gyro itself), and I think these are correct.

I have watched Jasmine's great build videos (which were invaluable in the build), but I am confused by the bit where the gyro setup is covered - uses "Auto" on the DX7 which I do not understand.

After some advice from another forum I have now ensured Aux2=Aux2 and Gear=Gear in the "Input Select" screen. This means that with Gear switch in 0 position gyro light is green (HH) and in 1 position gyro light is red (rate mode). So far so good.

Have gone into Travel Adjust and changed Gear to (0) +30% and (1) -30% [as per the advice].

If I move rudder stick on Tx to the left, tail slide moves to the right towards the blades and if I move stick right it moves towards the boom - so this I think is all OK.

HOWEVER!!!! In HH mode (gear switch at 0), if I move the nose of the heli to the left or right, the tail does not move at all - stays still - surely this is wrong? Gyro should be correcting movement, but it seems not to be. Have tried changing the Gear Travel Adjusts to different percentages but does not seem to affect things.

Any help greatly appreciated!!

[heli-on]

When the main balde spin clockwise, the rear rotor should be coming up towards the main blades at the leading edge of the disk. To put it another way, looking at the heli from the right (TR) side, the tail rotor should be spinning counter-clockwise.

If that's correct, try reversing the direction on the gyro. You may also need to reverse the rudder channel on the radio.

[AlasdairM]

Hi Heli-on - thanks for reply.

Main rotors and tail rotors going the correct way.

My problems are really

(a) the sensitivity of the giro and how to adjust correctly on the DX7. If it was a DX6i I would be able to do it in my sleep, but DX7 seems very different despite both being Specktrum! and
(b) some explanation of why the giro in HH mode is not moving the tail rotor when I move the heli around.

Sunday night over here in the UK - so I am not at my best!!

Regards, A

[Jasmine2501]

If your heli does this - the gyro is reversed... this is one of the saddest videos I've ever seen, the guy keeps messing with it, but the one thing that would have fixed it, he does not do... put training balls on your helicopter and see if it does this - with no rudder input. Then when you get it to hold, check your rudder direction by giving it a bit of rudder and see if it moves the way you want.

txxJPu1Dn7M

[Mikej]

Alasdair,

The way that I always check it is to have the heli nose pointing away from me, then give right rudder - the servo arm / wheel should move forward pulling the tail slider towards the boom, if not you need to reverse the rudder channel. Once you have that correct and with the nose pointing away from you again move the tail sharply to the right (i.e. nose left) and the rudder servo arm should move forwards again - if not you need to reverse your gyro direction.

Good luck.
Mike.

[AlasdairM]

MikeJ - many thanks. I have checked and am happy the rudder does not need reversing, as tail slider moves exactly as you say if I give it right rudder (i.e. towards the boom).

However the tail does not budge at all if I put it into HH mode and move the tail sharply - leading me to wonder if the gyro settings on the DX7 need to be changed somehow so that the sensitivity is increased perhaps and the tail does move if the heli nose moves?

Still confused in Cambridge!!

[Jasmine2501]

MikeJ - many thanks. I have checked and am happy the rudder does not need reversing, as tail slider moves exactly as you say if I give it right rudder (i.e. towards the boom).

However the tail does not budge at all if I put it into HH mode and move the tail sharply - leading me to wonder if the gyro settings on the DX7 need to be changed somehow so that the sensitivity is increased perhaps and the tail does move if the heli nose moves?

Still confused in Cambridge!!

Did you watch my gyro setup video? At a certain point, the gyro does not do anything. If the gain is too low, it will essentially not respond at all, and there's a point where it's totally wigged out and doesn't know if you want HH or Rate - the big light on the gyro should be solid green...

[Mikej]

MikeJ - many thanks. I have checked and am happy the rudder does not need reversing, as tail slider moves exactly as you say if I give it right rudder (i.e. towards the boom).

However the tail does not budge at all if I put it into HH mode and move the tail sharply - leading me to wonder if the gyro settings on the DX7 need to be changed somehow so that the sensitivity is increased perhaps and the tail does move if the heli nose moves?

Still confused in Cambridge!!

Alisdair,

I should have said - have the gyro in rate mode when you are doing this - in HH it works slightly differently and can confuse things.

What gyro and Servo are you using ?

Mike

[AlasdairM]

Hi Mike - stock gyro and servo - i.e. Align GP700 gyro and DS420 tail servo.

Alasdair

[Mikej]

What happens if you put the gyro into rate mode and move the tail as described ?

[AlasdairM]

Still absolutely no movement of the tail if in rate mode!

[Mikej]

It sounds as if it's buggered :):)

Do you have another gyro that you can try on it ?

[AlasdairM]

Could take a 401 out of my Raptor 30 or Trex 500 - but will probably wait until tomorrow (Monday) and go back to shop I bought the kit from and hopefully they will agree to change the gyro - although I guess it may take some time for one to get to the shop unless they have a stock of them (unlikely!).

Thx for all your help, A

[Jasmine2501]

OK do this for me
1. plug the rudder servo directly into the receiver on rudder channel and wiggle the rudder stick - if nothing, then bad servo
2. Plug the gyro into the rudder channel and the gain wire into the gear channel on the receiver. Do not plug in the servo.
3. Put your gyro into programming mode and wiggle the rudder stick - light should change from red to green and back. Set it back to green for the first option and let it exit programming mode by just waiting a bit. If it doesn't do the switch, something is wrong with gyro or receiver, or you plugged it in backwards.
4. Now plug in rudder servo to gyro hole, making sure that signal wire of servo is facing towards the middle of the gyro, and black wire is to the outside. Set gyro gain exactly as I have it in the video, and make sure throttle hold is active - you will see the "1" blinking like in video. Gyro should react - if not then bad gyro probably.

Tell me what happens at each of these steps - I will check back after dinner.

[AlasdairM]

Hi Jazzy - it is close to midnight here in the UK so am off to bed - but will do exactly as you say tomorrow and will post response.

Enjoy dinner!

Regards, A

[AlasdairM]

OK do this for me
1. plug the rudder servo directly into the receiver on rudder channel and wiggle the rudder stick - if nothing, then bad servo
2. Plug the gyro into the rudder channel and the gain wire into the gear channel on the receiver. Do not plug in the servo.
3. Put your gyro into programming mode and wiggle the rudder stick - light should change from red to green and back. Set it back to green for the first option and let it exit programming mode by just waiting a bit. If it doesn't do the switch, something is wrong with gyro or receiver, or you plugged it in backwards.
4. Now plug in rudder servo to gyro hole, making sure that signal wire of servo is facing towards the middle of the gyro, and black wire is to the outside. Set gyro gain exactly as I have it in the video, and make sure throttle hold is active - you will see the "1" blinking like in video. Gyro should react - if not then bad gyro probably.

Tell me what happens at each of these steps - I will check back after dinner.

Hi Jasmine and all other kind posters.

First thing today I tried to do exactly as Jazzy asked, and got as far as number 3 and all was going well - i.e. servo is OK etc.

When I plugged the rudder back into the gyro there was a quick twitch of servos, and then nothing! :arggg::arggg: I tried several times all to no avail, so unplugged ESC and plugged 6v Rx battery directly into receiver - and all servo movements etc worked. Checked LiPo and it still had over 4.0v per cell. So LiPo all OK and receiver etc also OK - possible ESC problem?

I took the 250 back to model shop this morning, and they diagonsed that the ESC had given up the ghost. They have given me a new one (not Align :thumbdown: as there are no spares available in the UK at the moment) so I need to solder the plugs etc. on to this and set it up. I can then go back to trying to sort out my gyro. :confused:

So please folks I am not ignoring your advice, and Jasmine I will go through your earlier points again as soon as I can and report back.

Thanks again, and if I do not get it done before the 25th, Happy Christmas to All :thumbup::thumbup::thumbup:

[Jasmine2501]

Well it wasn't what I thought, but by taking a logical approach, you did figure out what the issue was... that's what I was going at - you can't attack these problems randomly, you have to eliminate things one at a time, and then you can figure out what it is... good luck with it :)

[moonjoose]

My 250 did exactly this with the DX6i. I had to inhibit the Gyro on the TX, then it worked. Probably different for the DX7, but it's so often the little things you never think of...

[AlasdairM]

Hi again to Jasmine et al - you kindly posted replies to my problem re DX7, gyro settings and Trex 250.

Just to update you, and prove I am not ignoring your helpful advice, I have now had it confirmed (by the model shop that I bought the kit from) that th gyro is faulty.

So no wonder I was having problems - at least it proves I was not going ga-ga.

Bit of a bu**er as I have now had to replace both the ESC (which stopped working after a very short while and which the model shop changed free of charge at least) and now the gyro.

They have replacements on order, but warn Align seem to have very few spare here in the UK.

When I get the new gyro I will hopefully be able to enjoy the 250 and not sit looking at it!!

All the best, and thanks once again for your help, A