Setting up the Vigor for F3C
I get many emails asking "How much expo or dual rates should I use?" or "What's the best pitch curve for hovering?". Setup like this is very much a personal preference thing, but I decided that I would outline the setup of one of my helis to help some people with their own setups.
My Vigor CS is about 14 months old now, I brought it for the express purpose of doing competition flying and it has been very good at it winning the Sportsman class last year. This year I'm competing at the F3C with very experienced and talented pilots and the competition is much tougher.
With the competition much tougher this year, I wanted to ensure my machine was optimally setup to help me out as much as possible.
The engine runs on 5% nitro, 15% oil and 80% methanol.
I use the Futaba 9Z WCII transmitter.
I have only recently started to use the GV-1 so my throttle curves are still current. I have also spent a lot of time on the throttle curves getting them just right.
I like the RPM to come up very early in the curve so that the headspeed is
up to operating speed before the helicopter leaves the pad. The reason I do
this is so that then the response of the helicopter to pitch and cyclic will
be constant as the headspeed is not still increasing as the heli lifts off.
You'll notice that I also have a lot of negative pitch in my pitch curve. While many may disagree with my setup here, I like to be able to 'pull' the machine out of the sky in windy scenarios if need be.
Now that I use the GV-1, I have it set to 1550 RPM in Normal mode. I have found at this speed, the Vigor is quite locked in (the Vigors seem to like a high headspeed) and is stable in wind gusts, but not too twitchy either.
Idle Up One:
I tuned this curve by doing loops and ensuring that the engine didn't speed up too much on the downward side of the loop.
I added in 30% cyclic to throttle mixing (the SWP function on the 9Z) to help keep the engine constant in rolling stall turns.
I also found that in windy days when I really had to get into the negative pitch at the top of 540 stall turns to prevent the heli from 'travelling' you could hear the engine cut back as it went into the lower end of the throttle curve. To prevent this, I added a little rudder to throttle mixing (25%) so when I add rudder, the radio mixes in a little throttle which keeps the engine 'on song' in this situation. Careful not to add too much though else you will have the opposite problem of the engine speeding up. Once again, changes in headspeed will often show up in unwanted movement of the helicopter which the judges will nail you for. Doing this kept the engine at the same note throughout the maneuver.
Once again, now that I use the GV-1, all this mixing is redundant, I'm just leaving it there though for if the GV-1 throws a magnet or something.
I have the GV-1 set for a headspeed of 1750 in Idle Up One.
Idle Up Two:
With the GV-1 now in place, I set it for a headspeed of 1850 in Idle Up Two, at this speed, the CS rolls very well.
I found that this setup hovered well, but in gusty winds did not of the precision control to counteract the wind.
I was expecting the aerobatics to suffer, but was pleasantly surprised to find they didn't. It was the lack of precision in the hovering which encouraged me to continue to research.
After discussing setups with various other Vigor pilots, I decided to install one of the 'O-ring' dampener kits from Ron Lund with hard and soft ring combination and see what the results were. The head tightened up considerably, trying to move each blade grip up and down yielded little movement compared to the grey dampeners.
As expected, I found the hovering to be quite 'twitchy' now but very precise. The aerobatics had a more precise feel to them also. Knowing that I could address the 'twitchiness' with flybar combinations I decided to stick with this dampener combination.
First of all, I moved the weights all the way out to the paddles. I found that this yielded pretty good hovering performance but it was very slow to roll. Very good if you only have to do one roll in the schedule, but doing two at this pace was just making hard work for myself. I then moved the weights all the way in and found that hovering stability was not that great in that the helicopter felt like it was always on the move. However it rolled very quick. I put the weights back to where they had been (halfway along the flybar) and found that was the best compromise.
Now that I felt I had the dampener and weight parts sorted out, I wanted to see what impact shortening the flybar would have.
I got hold of a shorter KSJ flybar and fitted that up with the weights all the way into the head but still with the Hirobo weights in the paddles.
First impressions of this combination was how well it seemed to hover in a
very gusty environment. I removed all the expo and delays from the aileron and
elevator controls in normal mode which made the heli a bit more responsive.
Later that afternoon I fitted the GV-1 and set the headspeed to 1850 (up from about 1680 or so) in Idle Up Two, this increased the roll rate considerably and made the heli perform as desired. I could then have a nice docile hovering setup without sacrificing roll rate in Idle Up Two.
DUAL RATES AND EXPO:
I use exponential on the rudder because I want the tail to be quite insensitive because there are no quick rudder movements in the hovering maneuvers. Piroettes are three seconds in duration so blazing pirouette rates are not required. This also means that any 'unwanted' inputs by my fingers do not show up as much.
Idle Up One:
Idle Up Two:
This is a fairly detailed explanation of my setup, feel free to critique the setup and/or pick and choose bits of it for your own setups. Remember, setups like this are very much a personal preference type thing. Something that works well for me may not be suited for you.