Got my AR in the air for the first time this morning. This is my first "speed" plane.
I got it all buttoned up last night, and snuck it in the car "just in case" I had a few minutes on my way to work this morning. Turns out I did, so pulled over to my favourite (large) park, and let her rip. Not before taking a few snaps with the phone though, so I can remember it in case the worst happens ;-)
I gave it about 1/3 throttle and pushed it up and away. It was a MASSIVE handful right away, as it needed about all the up trim I had and a good deal of right as well to prevent it spearing in at the closest piece of dirt. I nearly lost it at one point as it ended up quite far away and was very hard to see. Managed to gather it all in though, and eventually got the time to hit the trim buttons for about 40 clicks. After getting it straight and level (phew!) I spent the remainder of the first pack just cruising around, getting a feel for the low speed handling, with the occasional squirt of full throttle. Jeeeeezzzzus this thing moves out! One observation is that I'm not sure the little 5g servo is enough for aileron. I tried a fast roll with full aileron deflection, and the roll rate was not much faster than when at low speed. I think the ailerons are being blown back at high speed, but I need to test it some more to be sure. It's not a problem though. I was pretty happy with the thrust line as it was pretty consistent on trim with power on and off. After that I brought it in for a nice landing on the short grass, right on the battery. It slid to a stop right at my feet. I was originally worried about landing on the battery, but the slick morning grass is no problem at all as it just slides along without digging in.
After landing I noticed the elevator had quite a bit of up deflection at neutral to stay level. I'd set the CG at 1" from the leading edge as suggested earlier, and I'm going to try moving the battery back a bit and see if it settles out. It flies OK as it is, but it feels naturally nose heavy when inverted so I think I can move the CG rearward quite a bit from here.
So as for my specs:
Motor: Turnigy 2730 3000kv
ESC: Turnigy plush 18A
Prop: TGS sport 4.75 x 4.75
Battery: Turnigy Nanotech 3s 850
Servos: 2 x HXT500
Full power on the ground is just under 24A for 271W, but I don't think I'm getting that in the air.
Overall I'm pretty impressed with this thing so far, but part of that is that I've never flown (or even seen for that matter) anything quite this fast before. The build took much longer than expected. From reading the first post on this thread, you might think you'd have it done in an evening, but in my case I'm a notoriously slow and meticulous builder, so I'd guess I'd put 10 - 15 hrs into it. That's all my fault though, as I elected to scratch build everything from the plan, and to cover all the balsa parts with laminating film. I also took a while deliberating over the motor mount, and in the end I machined up a threaded offset bush to locate the plastic motor mount on the 5mm carbon tube at exactly 3° down and left thrust. Works like a champ and is very secure, but is overkill.
179g, 6.3oz all up. so at 277w that's 688 watts/lb. Can that be right?
Need to check that in the am.....
the flying battery haha
Wow, this is an old thread! My adrenaline rush died a couple of weeks after it's first flight. I pulled too much elevator in a turn and snapped the wing! I fixed the wing and bagged it in fibreglass, but never got around to finishing it. Since then I've had faster planes, and never really got back into fast little things.
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