Vigor CS - My thoughts
Towards the end of November last year my Vigor CS finally arrived, however due to lack of available time I didn't start building it until early January.
Here in New Zealand, the bulk of our competitions are scheduled in the December to April period in an effort to take advantage of the (supposedly) good weather during our summer months. I competed in the first competition in December with my little Ergo 46 because my Z230 was still out of action at that stage.
I came back from that competition determined to get the CS going ASAP and use it in the next competition just over a month away. At that stage I still hadn't decided on a power plant for the machine yet. Should I go with the tried and tested OS 60 with Muscle Pipe, or try the new OS 91 with the KSJ Muffler? In the end I decided that you only live once and so I went for the OS 91 combo.
The first thing that really impressed me was the enclosed drive pinion. The pinion is supported top and bottom by bearing mounts which makes a great change from both the Ergo 46 and Z230 who only support their pinions at the top.
The rigidity of the frame assembly also stood out, you could just feel it as you put it together
The installing the brass grounding plate required a little bit of extra work. The holes didn't line up correctly and had to be slotted out and when this was done and assembled, it was found that the landing skid mounts didn't sit flush on the carbon bottom plate. This was fixed by milling an amount equal to the thickness of the brass grounding plate off the bottom of Cross Member 'B'. This allowed the landing skid mounts to sit flush on the bottom plate.
I set my Vigor up for 140 CCPM using the 'standard' range setup.
The split gear tail drive is a great feature that impressed me, very simple
and very effective. At first I was concerned with the gear meshing, it all seemed
a bit tight. However, with the CS, you cannot really get it wrong, there are
no slotted holes to line things up with. You just bolt the components in and
they line up.
Another problem with the canopy was the lack of clearance between it and the frames, servos and linkages when mounted. It rubbed up against the linkages and the servo output arms.
The person painting the canopy made such a good job of it that we were too scared to drill holes in it to mount it to the frames in case we got it wrong. One day while crusing around Ron Lund's website, I found how he had mounted his canopy using internal mountings. Because this meant that no drilling was required, we decided to investigate this option further. Darryll made up some prototype mountings and expoxied them to the inside of the canopy. The standard canopy standoff's were replaced with Darryll's creations and it seems to work quite well. The canopy stretches over quite well and fits very securely as well as providing a nice seamless finish to the canopy.
One thing I'm very much over is the plastic servo mounting plates that are secured by CA Stopper rings. These things require a fair bit of tightening up in order to ensure the servo doesn't move in its mountings. These are used to secure the rudder and throttle servos. The cyclic/collective servos are mounted very securely the servo tray and frames.
I slowly raised the throttle and got the blades spinning just below hover RPM. I did this for about 30 seconds then let it ilde again for 10. Each time I kept the blades spinning for 10 extra seconds. I never got the machine off the ground because I wasn't sure how the machine would handle, and in the tight confines of Darryll's back yard, I didn't want to find out just yet.
Once the first tank was emptied, we examined the machine to ensure that nothing had come loose and that everything was still fine. It appeared so, so it was down to the riverbed to get it off the ground. I had set the throttle curve quite low in order to run the machine in, this resulted in a low headspeed which the Vigor didn't really seem to like very much, it was a little unsteady at first. Again, after this tank, the machine was examined to ensure that it was still fine, then it was off to the field for some more tanks.
Raising the head speed made the Vigor settle down into a steady hover. I still had a low normal mode throttle curve to ensure the engine didn't stress itself during run in.
After six flights of easy hovering and circuits, I set to work on setting up the hover better, adding in Dual Rates and Expo to get a smooth controlled hover for competition style hovering.
Another few flights and setup of Idle Up 1 flight mode and it's first loop was attempted only to find I obviously wasn't getting the cyclic pitch that it needed and the big 91 obviously wanted to pull a bit more pitch. A session on the bench revealed that some creative grinding with a dremel as suggested at Ron Lund's site was going to be called for in order to pull 11 or 12 degrees of pitch and still use cyclic without binding.
Rolls were then attempted and the machine rolled like an arrow.
A week later and the machine was put through the competition maneuvers that we do in the class that I'm in here (Sportsman, the intermediate class below F3C), loops, rolls, 540 stall turns, split s's, all went well with the faults being those of the pilot, not the helicopter. The forward speed of this thing is quite breathtaking but is fuss free and definately not nervous.
Once again, a visit to Ron Lund's site provided some idea of the modifications required. First of all, the bottom of the head was modified with the dremel to enable the linkages from the washout arms to the flybar to get full travel without hitting the head. Then, the dremel was applied to the metal just below the head to allow the linkages that connect from the washout base to the see-saw arms that connect to the blade holders to get full travel without binding on the head. This allowed 11.5 degrees of pitch without any binding when cyclic is applied. I have setup throttle hold for 13 degrees of pitch.
With this setup I still get -9 degrees of pitch at the bottom end. Of which I only use -7 (this machine is setup for FAI style flying).
The engine quit on me a couple of times while changing from ID 1 to Normal which resulted in a couple of low altitude high speed autos which rated high on the pucker factor scale. Sorting out the needles better ended that problem.
After 8 3/4 hours, the ball link on the carbuettor arm fell off. Just one of those things I suppose.
Starting this thing can be a real pain in the ass if you don't have a decent starter. To start it with my starter I had to unscrew the glow plug 2 turns and crank it. This arrangement didn't turn me on at all, so I invested in a heavier duty starter. I haven't tried it out just yet, but I'm hoping that it'll end my woes.
I fear for the life of the one way bearing in the clutch sometimes, although I think my starter is at fault here as it is not strong enough to crank it properly, yet strong enough to send nasty shocks down the starter system into the one way bearing. We'll see how it goes with the new starter.
Flying my Z230 now just doesn't have the same appeal, it's just not that exciting after flying the CS, so I'm putting the Z230 up for sale and will use the proceeds to get a Futaba 9Z WCII.