[NSRCA-discussion] Spektrum DX-7 quick setup...more on throttle to elevator mix...

[tocdon at netscape.net]

For those using the DX-7 Spektrum for pattern flying, I did a 9 step process for setting that radio up as a competitive pattern flying plane.? Krishlan, please feel free to print this in the K factor somewhere if you think it's informative.

http://www.rcuniverse.com/forum/m_5876308/tm.htm

Of interest, for example, "The reason I use P-MIX 2 and 3 is used when doing throttle to elevator or aileron 
because these don't tie the throttle trim to the mix. So you down-line mixes will not be effected by throttle trim adjustments. 
This is similar to the ORIG on the JR 10X." 



Quick setup for Spektrum DX-7 for an RC Aerobatic Aircraft, by Don Szczur

The 9 steps to setting up the DX-7 for your pattern plane that has two aileron and two elevator servos: 

Go to the system mode (push the down scroll and select buttons, while turning on the Tx). 

1. Scroll to model select, choose a model number. Scroll to model name, (increase or decrease to select each letter). 

2. Scroll to dual rate. Set up a dual rate switch ( I like all my dual rates tied to the aileron switch, but you can leave them on each individual or choose to put them all on another switch like the flap, elevator, rudder). 

3. Scroll to wing type, select flaperon on. Scroll down one more to input select. Select Aux 2: INH. TRIM: INH. Flap: INH, Flap TRIM:ACT This gets everything working with the trims, takes the flap switch off, normally I don't use any kind of flaps on any of my pattern models. 

Thats it- you are done with the system menu. There is a neat function which I did not set up but its called throttle recovery. If you beep down all the way to kill your motor after a flight, when you beep once back up it goes to your pre-set position, ready to start the motor again. 

Go to Function mode: Turn off the Tx, push the select and up scroll while turning on the Tx. This gets you to the Function mode. 

4. Scroll to reversing SW and set up any servo reversing you need. (you get to this by holding select and down scroll and it gets you in to make the reversing). 

5. Scroll down the P-MIX 6 and go elev to Aux 2 (plug in to your left elevator servo). Adjust rate to 100% (move elevator stick up and down to do this). Set SW: ON. Use P-MIX 6 for this because P-MIX 5 and 6 include trim. You want the elevator trim to move both elevator halves up and down. 

6. Scroll up to travel adjust. Get your CRC or similar meter and fine tune your travel up and down on ailerons and elevators. Remember you want to get them mechanically set as close as possible then use the travel adjust to get the throws perfect. Suggest only using plus or minus 10% from 100% because more than that will distort your control speeds (for aileron and elevators, you will have one servo moving faster then the other- even if you cannot see the difference, it will be there). 

7. Scroll to D/R and Expo and set for elevator, ailerons and rudder. (remember its positive expo for softer center). Suggest when you set up dual rates you use a proportionally higher expo with high rates, as compared to low rates, to have the same feel around center. For example, 20% expo on low rate (75% D/R) and 28% expo on high rate (100% D/R). 

8. Set timer (Down- Stopwatch, etc.) if you use a timer to avoid dead stick landings. 

9. Advanced P-MIXES. I have the following. 
I set P-MIX 5 to Throttle to Rudder. +1 high throttle, -1 low throttle. Offset 0 
I set P-MIX 4 to Rudder to Aileron. I have a few percent in for right rudder to give opposite aileron. Offset 0. 
I set P-MIX 3 to Throttle to Aileron. (I don't use that but set it up in case needed) Offset -75% 
I set P-MIX 2 to Throttle to Elevator. 0 at high throttle, -17% at low throttle; Offset -75% 
I set P-MIX 1 to Rudder to Elevator. I have a few percent in for left rudder to up elevator. Offset 0. 
The reason I use P-MIX 2 and 3 is used when doing throttle to elevator or aileron because these don't tie the throttle trim to the mix. So you down-line mixes will not be effected by throttle trim adjustments. This is similar to the ORIG on the JR 10X. 

Done!?? Don't forget to re-bind with throttle stick at low before flying. This will make sure the throttle fail safe is set at low throttle. 



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