Dialing in plane and pilot for precise RC flying

Hi everyone -

As I wrote in my last post http://migsrus.blogspot.ca/2015/01/scotts-rc-goals-for-2015.html , I am in the process of changing how I set up my planes, my transmitter and myself to become a more precise and honest flying RC pilot.  I also forgot to add that I want to learn to be more relaxed and skilled when flying inverted, it is kind of my "RC kryptonite" right now, but with the process I am going through, I see that being a much easier thing to learn and hopefully master.

I shot a video at the field yesterday to hopefully better demonstrate some of what I am talking about.

Hopefully the video touches on most of the process that I have been learning with help from Stephan and his inputs from Dave Scott's Airplane & Radio Setup manual http://www.rcflightschool.com/Setup_Manual.asp , but I wanted to touch on a few highlights that stick out in my mind from going through this process.  I have my own copy of this manual on the way in the mail and will share more with the blog once I receive it.

The foundation of this all rests on setting up and flying a more balanced plane, so I would strongly recommend doing this first as it makes the plane much more balanced and predictable in what it is going to do from my experience.  Even with 3D style throws and tons of expo, my planes have been flying immensely better when properly balanced.  In my video and the video Stephan shot, we demonstrate the arc method of determining whether your plane is properly balanced.

There is no "class answer" on exactly what your arc should look like, you have to use some judgement there.  What I would say to look for from my experience is if the nose drops almost right away after you cut the power, the plane is more than likely nose heavy.  If the back end drops and the plane kind of "mushes" (sorry not the most scientific of terms) it's way through the arc, it is probably tail heavy.  

The plane should continue to climb after chopping the power and as speed bleeds off, transition across the top in a smooth, uniform arc before the nose starts to drop.  

Like any dialing in process, it needs to be done in steps, don't move the battery on your Mig29 back by 2" right away just because I did, take it in smaller increments maybe 1/4" at a time until you find the right balance.  You can do a couple arc tests, land, move the battery, try again, etc, so you can get several arc tests done in one battery to help speed up the process.

Once you get the plane balanced, don't be scared if you have to put in some trim to keep it level for certain parts of the flight envelope, sometimes the plane might want to zoom or descend on you at full throttle, so a few clicks of trim to help that out is not a bad thing.  This was one of the hardest ruts for me to break out of.  Now obviously if you are using half your down trim and are dragging around 1/4" of deflection in your elevators, the plane might not be balanced properly or the elevators were not dead center at zero trim, so you might want to recheck the balance point and the control surfaces.

I mention this at the end of the video and will mention it again as I learned this while going along and I think it is very important to the process.  It is important to ensure that your control surfaces are dead center when you have zero trim.  Over time especially with scratch built park jets, I have found as hinges and linkages get broken in, what was once center with zero trim can shift, causing me to have to trim to compensate for that as well.  So I found it very important to be working from a point of dead center control surfaces as I dialed in my plane, my transmitter and myself to become a more precise pilot, otherwise I was battling against something which didn't need to be there.

What I found worked well for me once my plane was properly balanced was to then train myself to use the two finger method of stick control before playing with my servos and expo.  I now have about 50 flights using this method and will never go back to "thumbs only".  In honesty it took me probably about a dozen flights to fully get comfortable with my new hand position and control and it wasn't without a few mistakes... :/  So while learning this method, I kept my plane up a little higher than normal to give me recovery altitude if I messed something up.  

Then the next step was to start dialing down my expo.  As I have mentioned before, I was in the rut of at least 50% expo on everything as a way of smoothing out my plane not being balanced and essentially what were 3D setups in my radio and with my servos and linkages.  So again, baby steps here, dropping no more than 5-10% at a time, get used to that, then drop again until I got dialed down to 20% expo on the pitch and roll and about 35% on the rudder.  I am still working on the rudder setup, but with the planes Stephan and I have modded and fly, we like having large rudders to help compensate for prop wash in high alpha and other rudder dominant moves, so this may be an area of compromise.

Then the last step I did which I show in the video was to move my linkages as close as possible to the servo to give smoothest response.  Even then with 100% throws, this reduced the travel of my control surfaces, but I am actually very happy with how the plane flew.  As I mention in the video, in future builds I will use different control horns on my rudders and elevons to give me more flexibility in being able to adjust my control surface deflections mechanically.  Awhile back, Stephan was kind enough to send me some control horns from Flitetest http://store.flitetest.com/control-horn-20-pieces/  One of their control horns is on the right compared to a Grayson Hobby control horn which I have been using.

I have at least another 1/8" of control horn to work with which should give me lots of flexibility in getting the control surface travel I want.  Plus, they are much cheaper, $5 for 20 compared to $2.99 for 4.  

As soon as I moved my linkages closer to the servo, I noticed how much smoother the surfaces were moving.  When I had the linkage at the end of the servo arm, the action could be very "jerky".  Of course I am using inexpensive nylon gear servos, but helping the servo out in it's job has helped out the precision I feel and see in how my plane flies.

So although that was the last piece of the puzzle, there is still much work to be done to master the whole process and convert my fleet over, but it has been well worth it.

I found that by following the steps that I did it was actually a very smooth transition, much less difficult than I originally expected.

So again, I'm not trying to be an evangelist here or anything, but if you are looking to push your plane and yourself to a whole new level, these techniques might be worth a try.  If nothing else, next time you fly, try the arc test with your plane and see how it responds.  As I mentioned before, if a person was to try nothing else other than to ensure their plane is balanced on neutral CG, they will immediately notice a difference in the balance, predictability and improved handling of their plane, at least that is what I have learned.

Cheers,

Scott