Swapping Tx & Rx queries.

[Heliboy31]

Background:-

I have a Trex 600ESP (Pod & boom with Flybar!!) which flies just perfectly for me. It has an AR7000 (Dsm2) Rx with Sat. which were bound to an older type Spektrum DX7 Tx. (see photo).

It is my intention to fit the heli into a scale body with some retracts, lights etc. which needs a couple more channels so, just as a preliminary step, I decided to rebind the Heli with the existing AR7000 Rx with my DX9 Tx (DMX & DSM type).

As these are both computer (digital?) based Tx's I thought I only needed to transfer all the settings (Sub trims, Swash mix, end points etc) directly from one Tx to the other and all would be fine.
It is pity that the old DX7 Tx doesn't have a SD card port like the DX9 but it didn't take too long to copy the settings across manually.

I did the rebind --- no problems there, but disappointingly, I found that my lovely "level swash" setup was now all to c*#k!
I had to completely redo the servo "90" sub trim settings, set up new end points, adjust the swash mix a bit etc etc.
Servo directions were OK!!
Whilst this wasn't a huge problem, it has now left some nagging doubts in my mind.....

Questions:-
1. Is this issue of needing to redo the setup because the DX7 is of an older type of (digital?) technology compared with the newer Tx's or what?
2. If I swap my new DX 9 settings (using an SD card) to another DX9 (or one of the new generation DX6, 7 or 8's) do you think I would likely need to reset the head/swash again?

and...
3. When I put my new(ish) 8 or 9 channel (Spektrum) Rx in the heli and rebind with the DX9, do you think I will have to reset-up the head, swash & servos again?
4. Do you think it will make any difference if it is a DSM or DMX Rx?

Thx in anticipation.

[trillian]

I think the reason for the differences in subtrim and other parameters is because the older DX7 is just calibrated a bit differently in places. Some parameters go to 150 instead of 100 being the max etc.

I have also brought over all my helis from the older DX7 to the DX7s. so I've done a bit of this myself as well.

In answer to your other questions:

2. No, once you have everything set properly in the DX9 it should translate straight over. (I have transferred heli setups between the DX7s, DX8 and DX9 with no changes needed)
3. Changing out the RX will not alter the setup either, it should all work just as it did with the AR7000
4. Nope, makes no difference - I have been told this from developers of current FBL systems with regard to DSM2 or DSMX sats, in practice the only difference would be if you fly in an environment that is so crowded that it exceeds the amount of DSM2 channels, which is extremely unlikely.

[bigpops]

1, 2, 3 - I'd always do a full setup when changing radios, unless it was like for like (DX9 to a replacement DX9 should work perfectly). Even then, I'd check everything.

4 - I've had lockouts on DSM2. These were at a range of only about 30 metres. I never had any trouble on DSMX.

If you fly out in the countryside, I'm sure you'll be fine on DSM2. I personally wouldn't use DSM2 on a helicopter these days. A micro foamy plane, maybe, but not anything with that could cause injury.

[coolice]

Hey buddy.

I've experienced similar and it's just basically through the different radios calibration settings to the stick potentiometer's. I've even seen same type transmitters (DX8 and DX8) have different centres ;-)

So I'd say;

1. No its more likely the different Tx stick calibration data.

2. Possibly, again I've seen difference's between Spektrum radios so if I was going from one DX to another totally different DX Tx (same model type or other) and using it to fly the model, I'd check the settings work.
The only time I wouldn't is if I was using another to buddy box using the original Tx as the master, as the 2nd Tx is just using the stick inputs and not the calibration points.

3. No you'll be fine, the receiver just receives the same data and moves the servos. The Tx is where any differences would originate from.

4. Not specifically, although DSMX does benefit from the high resolution and faster transmission rate. Probably undectable but it all helps I think, so if you can use the better transmission protocol I'd say use it.

Ian