Hi,

So I have been using a Dx5e for quite some time with my Apprentice 15e and decided that before I get another plane, I want to upgrade my transmitter so I can bind more to it later down the road.
After some research I decided on the DX7s.

So far I am loving it, I have tweaked it to my liking but I still feel I am not maximizing and maybe have some settings off. Today for example I lost control of the plane a little bit and it was very jerky even though I had the dual rate enabled (set it to 75% on all controls with 20% expo). I think I could use higher expo.

My settings entail 75% Rate as mentioned, 20-30% expo (increased today after crash), and I have been playing with Mixing on the Aileron/Rudder, giving 25% Rudder with Aileron movements.

What do you guys recommend/or do and what are some good tips you can give me? I am currently using an E-Flite Apprentice and I just bought a PZ T-28 which I have not flown yet (kind of scared :-) )

Thanks all in advnace

You just have to experiment. 75% movement might be a bit much for the style airplane and 25% might not be enough expo. If you are used to your DX5e try to set up your DX7 to have the "feel" you are used to and gradually migrate to a more aggressive setup. I have a DX7 and I normally have more expo dialed in and of course it depends on the surface. For me Rudder, and Elevator are usually less expo than ailerons, at least on my planes because I tend to use aggressive aileron servos and I have to dial them down some. I have some set to 70% expo and some with as little as 25%. Again it really depends on the plane.

One thing I do with my radios is while I am learning is to read over the manual a couple times, then go out and practice some. After I use the radio for a while, I then read the manual again. Each time it seems I am able to further my knowledge and usage of the features of the radio to get the most out of it for my use.

Thanks for the feedback. I agree with reading the manual and have done it twice, but prob could use a coupld of more times. As far as the experimenting goes, I agree as well but unfortunately sometimes the plane is not as forgiving to the experimenting as I believe happened today :-) and crashes happen. I think there is some standard initial setup for these types of planes and your feedback certainly helps. Any other suggestions from you or the other members will be greatly appreciated. thanks

I have set up countless planes with my radio over the years but I still have my instruction book on my lap every time I do it. Once I somehow tossed it out and have never figured out where or when so I downloaded one from the net and printed it out. Things like expo is something you will just have to do as trial and error from plane to plane. My radio has expo on the throttle servo too so I use it there but make it more sensitive. I like the throttle to move faster. Keep playing with it and you will find a lot of things you like and don't like to use.

I've got 2 DX7S's and love them...
if I'm experimenting with a particular setup and assuming I haven't filled the TX up, I'll use the COPY function to copy the airplane's profile to a new (blank) profile.
(giving it a unique but Similar name... say 'Sbach' and 'Sbach3D')
I can then make changes to the Sbach3D program... changes that work as expected are then made to the Sbach profile, changes that don't work as expected are removed from the Sbach3D profile. (alternately you can also copy the original Sbach profile to the SD card.. in case you want to revert back)
also don't forget when setting things like D/R, Expo, servo travel etc, you need to set it in BOTH stick directions, and possibly with which switch (example, if changing elevator travel, remember to set both UP and DOWN travel, if setting expo, remember to set it either by flipping a switch, or set it to be 'ON' all the time)
+1 on READING the manual gobs of information in there!

Hi!
First of all get ride of all the sloop in the system (aileron,rudder and elevator)! Second use 100% throw or more when it comes to throw on all channels! You fix the throw mechanicly first and then just do some minor electronic trim.
On a trainer no expo is needed! Just trim it out right and fly! Never ever couple the side rudder to the ailerons!!!
If you can't trim it out yourself ! Get help from a friend in your club who can! -You are a member of a AMA club aren't you!

I agree with Jaka on getting the slop out of the system and mechanically trimming the airplane as much as possible before going to electronic trim. Personally I too am not a big fan of dual rates, my thumbs provide that function. I do however use expo the value differs airplane to airplane, and control surface to control surface. I use expo to dampen out cross controlling; for example if I move the right stick wishing to apply elevator if the ailerons move I will add aileron expo to remove that issue and so forth. Most of the time my expo is setup around 35-40% on most of my airplanes. I have flown another pilot's airplane with high expo's around 80% finding it to be uncomfortable for me making the stick movements too large before the surfaces move, bringing on the control surface movements on too quick (too much throw all at once) once the stick reaches the point to where control is activated beyond the expo dampening point. To each their own, I prefer my setups to be more linear.

Good morning Steve. Great reply.. very tactfully done..

I also use expo on all my planes. I find that I like the soft handling during normal flying (without aerobatics) but like the agressive handling when maneuving for aerobatics. Expo give me just that and I can do it without dual rates. I just set everything up for the maximum deflection recommended then use expo for the normal flight... I said that already didn't I. But, you get my point I am sure.

I am also a big fan of mechanical before electronic trimming. I had a plane that I set up a while back that I could not get the darned controls to move to full deflection, including the throttle, which is where I was having the most problems. I was trying to get full throttle control using end points and really screwed things up in the process. So, I went to the field and a friend helped me work it through.

What I originally did was copy a plane settings into another model memory and then tried to make that work. What works for one plane may not work as well with another. This was the problem I ran into. So, he showed me how to restore all controls to the factory setting, without anything added electronically, then we proceeded to set things up properly mechanically.

THEN, we did the expo settings and minor settings on end points.. note minor settings to finalize the initial trim. Then, all electronic trim that was put in during the maiden flight was adjusted out mechanically so that center sticks with no trim on the transmitter had the plane set up for flight trim with very close to straight and level at about 1/2 throttle. That left me with plenty of wiggle room for both throttle and trim. So, subsequent first-flight-of-the-day flights required a minimum of trim to get straight and level flight and the rest of my flying was fun time.

BTW, I got your voice mail yesterday - jeech.. what a week. I will call you either tonite or tomorrow. Julie is down in Bradenton this week and I am stuck here in NJ feeding the cats and working.

CGr.

One word of caution. You can use too much expo which puts you in a position where the control response is very agressive at the ends of the stick deflection.

If you use this on your Elevator channel on an a/c that needs significant Elevator deflection to hold low speeds on approach you could increase the pitch sensitivity rather than decreasing it.

Looking at the attached diagram you can see that as your stick deflection increases not only is the control response curve steeper than the linear response but it is assymetric around your new "neutral" point. i.e. You will get more elevator change when you increase the stick deflection than you will when you decrease it. This could lead to some potentially negative handling changes as you are trying to make the model easier to fly.

If you are testing changes like this you may like to do them on only one rate at a time. If the response on the changed rate (i.e. high) is adverse and makes things worse then at least you can switch back to low rate and land the plane in a condition you are familiar with to retune and try again. If you change the expo on both rates and the response is adverse you have a tough landing ahead of you.

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