RE: Help? Phoenix Models 63" Yak-54
Success! Maidened the Yak-54 this morning and all went well.
Running an OS91 with 15x6 prop. Possibly may alter this prop in coming weeks, but all ok to start off with.
The maiden was the convergence of three 'new' events - first fly of a nitro aircraft (have always flown electric - more on that later!), first fly of the Yak / brand new OS91 of course, and first fly at a real club (always flown at parks).
The flights were uneventful (somewhat boring for onlookers after it became evident that a crash wasn't on the cards!). One click of right trim, one click of up trim and no worries.
Couple of build notes (may or may not be relevant for others)
1) Placed the throttle servo immediately behind the fuel tank (had to construct a small shelf) - aim was to get more weight forward to help CG. Shelf was good to mount the AR7000 Rx as well.
2) Replaced the stock tank with a 16oz DuBro (much better match for the OS91) - this didn't seem to impact flight characteristics as the tank drained.
3) CG was achieved with the addition of approx 150g / 5oz of weight up front - will look for options to remove this (such as Greg's idea to move the engine forward - new mounts or make a small box?). Also, the pilot seems quite heavy so may remove him...
4) Lateral balance was out too, so had to add 10-12g to the left wing - possibly this was not enough to worry about, but not sure
5) Started with recommended control throws, but will increase in subsequent flights
6) Made sure I reinforced main areas with either CA or epoxy - some joints / bulkheads had little glue. The undercarriage held up well to the landings but will further reinforce.
Anyway, very impressed with the aircraft - it's a big jump from smaller electrics (largest flown to date is a 3D FuntanaX, 1100mm wingspan) to something like this, but well worthwhile. The biggest difficulty was landing as I kept overshooting - I found it just floated on and on unlike the electrics I have flown. I did about 6 touch-n-go's before finally landing on the second flight!
Lastly, thanks to Spacey for starting the thread and for everyone else who posted experiences and ideas - very helpful thank you.
cheers,
Boltor