...and all was well
This morning I managed to get the Phoenix 2000 out for a test flight. Conditions were not optimal, with a moderate breeze and some gusts. However, after standing in the field for a while assessing the weather, I decided to give it a go.
I'd fitted the Phoenix with the 2200mAh battery to counter it's nose-up characteristic under power and, considering how much lift this craft generates, had no concerns of it being too nose-heavy especially after how well the Walrus performed with the same power pack.
The larger battery also provides more power, making things more manageable when the glider goes into a climb, as it will hold the climb better giving you time to react.
So, feeling quite confident about the state of the rebuild and the weight, I launched the Phoenix with a bit more than half power and it took to the air quite happily. I had set the controls to full travel (very daring) with about 50% expo, however with the breezy conditions it was difficult to get an accurate feel of the plane's responses. Nevertheless it flew very well, with the lazy and floaty characteristic of its long wingspan.
While the flying went well, getting the Phoenix back on the deck proved more of a challenge, not helped by the fence running across the middle of the field. The problem was that on approach into the wind, the Phoenix doesn't make much headway. However, when it drops within two metres of the ground and the breeze slackens, it floats on and on. I had a few goes at this, including some emergency power climbs to climb over fences it wasn't going to clear...
...and the carbon prop
The weather this morning had calmed sufficiently to venture out with the Walrus for a flight. Not just any flight, the first flight with the 2200mAh battery installed in the nose.
The Walrus assembly instructions do not provide any particular clues regarding location of the battery. In an attempt to resolve the packaging issues, I had fabricated a battery tray directly behind the motor. This layout is similar to the Phoenix 2000 and worked well with the 1800mAh battery I'd been using.
Lifting the Walrus out of the car I could really feel the extra thirty grams of the larger battery, located well in front of the wings. However I held my resolve not to change-out the new battery for the smaller unit sitting in the car, and headed out. There was a moderate breeze blowing which would help the Walrus to get flying quicker, which was good.
All connected, I set the throttle generously and heaved the Walrus up. I was prepared for various scenarios, being prepared to hit the flaps if necessary to get a bit of emergency height, and perhaps having to nurse the gravid Walrus onto a high-power approach to prevent it from nose-diving.
My concerns, however, proved groundless as the Walrus soared into the air without a hint of imbalance or labouring under the heavier load. If anything, the heavier battery gives the plane a more planted feel in the air, and the higher output combined with the larger carbon prop transform the Walrus from an intermediate trainer to a sports tourer. It's performance is now much more three-dimensional capable of higher speeds and sustaining steep climbs.
With the good news of power and speed one would expect a nasty compromise on approach. However I am relieved to report that the Walrus floated into the breeze for landing absolutely happily, for a landing as easy as any...
...a battery of changes
My spare battery, having thus far survived several crashes in the Floater Jet, finally succumbed to serial abuse when I forgot to disconnect it after a flight. As usual with depleted batteries, I bumped up the voltage by charging it on the Accucell charger as a NiMH, then switching over to LiPO-charge. However, this time, the charger only recognised two cells.
I'm not sure what has happened, but checking the voltage on the balance lead of my good battery in comparison confirmed that one cell was giving no voltage. I have checked to see if perhaps there was a short or something with the leads on the individual cells but have had no luck.
So I've ordered two new batteries, opting for 2200mAh Turnigy units. This is the same rating but a larger capacity than my current 1800mAh battery. The main reason for the upgrade is not the capacity but the curious fact that the 2200mAh battery is shorter than my the 1800mAh, which only just clears the servos arms at full travel, even when pushed right up against the motor.
One concern, though, is that it weighs about thirty grams more than the 1800mAh battery, and it's located right up front. This is also the reason I didn't go for a higher C-rating, as these each weigh progressively more.
What may offer compensation for the increased mass is that I've noticed that the Walrus seems to generate more lift with the carbon propellor, perhaps because the larger spread of prop-wash from the bigger diameter generates more lift from the wings? Anyway, the batteries are still a few days away so we have time for some subconscious deliberation before then.
However, I'm generally thinking that the first launch will be with a good throw and plenty of power, just to make sure it doesn't plough in...
