Differential thrust with throttle cut on the 2nd throttle channel

[Ricky R]

Just about to give it a try on a test model.

Excellent. Let me know if it works.

[xviper]

I can't resolve the Aux2 thing. When I activate CUT, Aux2 still works and in fact it goes all the way to +100 on one mix and on the other, I can't get it off the middle no matter how I mess with the rates. Also, is step 5 a typo? You say ON>AX2. Should that be THR>AX2?

[Ricky R]

I can't resolve the Aux2 thing. When I activate CUT, Aux2 still works and in fact it goes all the way to +100 on one mix and on the other, I can't get it off the middle no matter how I mess with the rates. Also, is step 5 a typo? You say ON>AX2. Should that be THR>AX2?

No, it's not a typo. In the IX, there is a selection available in the mix page called ON, and it took me by surprise also. As I said, step 6 was a bit of a curveball to me. Up to step 4, all followed exact as the author stated, but at step 6, my throttle went to low but the aux went back to center-however, they WERE linked, ie: when I advanced the throttle past half the aux followed. I then intuited that I should be able to change the rates for the aux to match the throttle, and I was able to, although my aux rates were different from the author's, the aux channel NOW followed the throttle exactly AND went to low with activation of the throttle cut. I hope this helps and you can get it working. Maybe being you have an NX and I have an IX is the difference.

[xviper]

You're probably right about the IX vs NX thing. I don't have an "ON", so I guess I'll just keep to the 3-pos switch. It was certainly worth a try. Thanks just the same.

[Ricky R]

You're probably right about the IX vs NX thing. I don't have an "ON", so I guess I'll just keep to the 3-pos switch. It was certainly worth a try. Thanks just the same.

Sorry and you're welcome. Some day I am going to try it on my DX8. I hooked my HK Lancaster to that, and never got the problem resolved.

[kallend]

Just out of curiosity I imported my iX20 Twin Otter setup, with differential thrust and throttle cut on a 2 way switch (H), into an iX14. It worked, BUT when I tried to set up the exact same assignments and mixes from scratch on the iX14, it didn't work. Must be something in the ISPM file from the 20 that the 14 can use, but can't create.

[Ricky R]

Just out of curiosity I imported my iX20 Twin Otter setup, with differential thrust and throttle cut on a 2 way switch (H), into an iX14. It worked, BUT when I tried to set up the exact same assignments and mixes from scratch on the iX14, it didn't work. Must be something in the ISPM file from the 20 that the 14 can use, but can't create.

Interesting. My IX 14 is my highest end radio so I can't try it, but I DID succeed with the instructions above with exceptions as noted. BTW, those instruction were for an IX 12.

[kallend]

From a Spektrum engineer, this is the accepted way of doing it on a DX9. I presume it works on an NX (I have no way of testig). It sets the second throttle channel to AX1:


First you need to go to Channel Assign and set AUX1 input to INH.

Mix THR > AX1 at 100/100%. Set "Trim" to ACT so throttle trim is copied over. Set the switch so this mix is active when the throttle cut is inactive. When the throttle cut is active, this channel will now jump to the center.

To fix that position, mix ON > AX1 using the same switch but in the opposite state. Adjust the right "Rate" until the output shows the same position as the throttle in the cut mode.

You now have two throttle channels that honor Throttle Cut together. Note that ThrCut position only affects the THRO port. You need use the ON>AX1 mix to change the other throttle cut output.

Now you can do your differential throttle by having RUD > AX1 and RUD > THR as you already understand.

[Ricky R]

But Viper said he doesn't have an "on" option in his NX mixes.

[xviper]

Nope ................... no "ON" when calling for mixes. I substituted THR and that didn't make it work. Diff thrust works very well, though.

[xviper]

CORRECTION. I do have "ON". I never scrolled far enough. It's the very last item in a very long list. I'll go back and try again. APOLOGIES.

[Ricky R]

CORRECTION. I do have "ON". I never scrolled far enough. It's the very last item in a very long list. I'll go back and try again. APOLOGIES.

LOL! I read your post (1st of the 2) and I'm thinking Kal has it on his DX, I wonder if I should ask Viper to check again, but you beat me to it! Good luck!

[xviper]

IT WORKS! "ON" is almost to the end of the list, 2nd from end. Didn't even have to play with rates to get the mid throttle down to -100. It was never there. I need to be more patient when trying to find something when scrolling.

That 3-pos switch thing came from a guy on YouTube (Kallend's link) named "Putzy Tart". He said he was working on something a lot simpler. I've been waiting. I'm not going to tell him you beat him to it.

[Ricky R]

IT WORKS! "ON" is almost to the end of the list, 2nd from end. Didn't even have to play with rates to get the mid throttle down to -100. It was never there. I need to be more patient when trying to find something when scrolling.

That 3-pos switch thing came from a guy on YouTube (Kallend's link) named "Putzy Tart". He said he was working on something a lot simpler. I've been waiting. I'm not going to tell him you beat him to it.

Well, like I think I said, I got it from a guy on RC Groups. I copied it and shared it here when it worked. I watched the putzy kat video, not sure if I tried his thing but if I did it didn't work for me. Besides, I wanted to have TC on H switch and diff thrust on/off on a separate switch too. I used the A switch and the gear channel because my model, a Grumman G44 Widgeon (build video on youtube), is a waterplane with no gear.

Congrats on getting it!

[xviper]

I've just programmed your method into my Canadair. On monitor, it works. I'll need to power up the plane to make sure I don't need to reverse something. At the time the Widgen first came out, nobody in Canada sold it and to ship it from a seller in the US cost almost as much as the plane was worth. I gave up on it.

[Ricky R]

Let me know. I haven't done an actual test either.

[xviper]

Couldn't wait for spring. Had to do it now. It works.

[Ricky R]

Excellent!

[kallend]

But Viper said he doesn't have an "on" option in his NX mixes.

He is mistaken.

EDIT: was mistaken

Curious that only the DX20 and iX20 have built-in multi engine aircraft types. I would have thought a 10 or 14 channel TX would have been an appropriate choice for a multi without requiring heroic programming..

[Ricky R]

He is mistaken.

EDIT: was mistaken

Curious that only the DX20 and iX20 have built-in multi engine aircraft types. I would have thought a 10 or 14 channel TX would have been an appropriate choice for a multi without requiring heroic programming..

Yeah, 4 different mixes, but the KEY was that "ON" to aux mix. I NEVER would have figured that one out. Big thanks to RCG poster "Basser." My search page gave me this link, and there is where I found the solution.
Spectrum iX12 differential throttle for twin - RC Groups