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Old Mar 21, 2012, 11:36 PM
Crashing into the sky!
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Auckland NZ
Joined Aug 2007
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What are you using to measure current?

And how many rpm is it pulling.
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Old Mar 21, 2012, 11:37 PM
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Joined Jan 2006
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Just tried the Ammo on a tired (3.4V under load) 3 cell and got about 30A w/a 4.1 so it should do fine tomorrow...ticked about the ARC. Just got it back from lightflight and it was unused till today..

(used a Wattmeter)
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Old Mar 21, 2012, 11:41 PM
Crashing into the sky!
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Auckland NZ
Joined Aug 2007
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What sort of wattmeter.......

Are you sure its a -2 (3750) and not a 2.5 (2800kV). Do a Kv check.






Current is irrelevant.








RPM determines how fast you go......



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Old Mar 22, 2012, 02:31 AM
Blue Sky Mining
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Australia, VIC, Miners Rest
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... current determines for how long ...
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Old Mar 22, 2012, 10:03 AM
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Its labeled a -2 but does act likes it the other wind. One of the 1st things I did was look at the other motor specs to see if it was an obvious mislabel. Maybe someday I'll figure out how to set the drill press up to measure the Kv but for now I'll let lightflight handle the Kv check....I'm just trying to figure out how to cram a large ESC in to get it up to 800W and still have a decent sized battery..
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Old Mar 22, 2012, 10:28 AM
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United States, AZ, Tucson
Joined Nov 2010
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Quote:
Originally Posted by stanordave View Post
Its labeled a -2 but does act likes it the other wind. One of the 1st things I did was look at the other motor specs to see if it was an obvious mislabel. Maybe someday I'll figure out how to set the drill press up to measure the Kv but for now I'll let lightflight handle the Kv check....I'm just trying to figure out how to cram a large ESC in to get it up to 800W and still have a decent sized battery..
That's where this dual aileron set up has multiple advantsges. Look at the space saved!
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Old Mar 22, 2012, 04:05 PM
Tim Lampe; Hobbico R&D
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Champaign, IL
Joined Dec 2009
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Quote:
Originally Posted by stanordave View Post
Its labeled a -2 but does act likes it the other wind. One of the 1st things I did was look at the other motor specs to see if it was an obvious mislabel. Maybe someday I'll figure out how to set the drill press up to measure the Kv but for now I'll let lightflight handle the Kv check....I'm just trying to figure out how to cram a large ESC in to get it up to 800W and still have a decent sized battery..
Not sure what other wind you are referring to, but the ARC 28-37-2.5 is good on a 4.75 x 4.75 - another ideal choice for the Rifle - flown it with that motor many times. Does 21,000rpm, 28A, 290W static (19.4A in flight), but that's on a 1500mAh 25C battey (3S of course!) (before I started flying our ElectriFly 1800mAh battery).

Not sure how to use a drill press to check the kV. All you need to do is somehow get the unloaded rpm (and know the Voltage with a Watt meter). You can simply cut a round flywheel from white plastic or cardboard or something, then mark two black lines on it, spin it up, then get a reading with our tach.

Tim
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Old Mar 22, 2012, 05:11 PM
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Well it flew fine w/the Ammo today. Launching it has gotten waaaay easier. Either my arm has gotten stronger or I have a better setup than earlier! Maybe its just better technique. Hardly loses any altitude on the throw. The dual aileron setup may come in handy when I start using 4 cells to keep the CG close (if a decent size 4s fits!)

for now, I'll go fly while ya'll go work

cheers,
Mike
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Old Mar 22, 2012, 10:08 PM
Tim Lampe; Hobbico R&D
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Champaign, IL
Joined Dec 2009
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Nice Mike.

What Ammo are you running - the 28-35-3900?

I've found that my launches are better than ever this year too. I have to remember to look at it when I throw it. This helps me keep the wings level.

Tim
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Old Mar 23, 2012, 12:14 AM
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United States, AZ, Tucson
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Not sure yet but i might be selling mine. Need to earn money for a much larger TRUE F5D
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Old Mar 23, 2012, 12:44 AM
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Tim, the Ammo 24-45-3790
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Old Mar 24, 2012, 05:12 AM
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Joined Mar 2012
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New rifle owner

I purchased the rifle today and I'm excited for the build.  This is what I have thus far, please advise if I'm on the right track to a good/fast flyer.

Motor: ARC 28-37-2
Prop: 4.5x4.1
ESC: Dynam Detrum 40A ESC(3A BEC) from hobby partz
Battery: HYPERION G3 VX 1800 MAH 3S 11.1V 35C/65C
Spinner: MP Jet Precision Spinner 30/3.2mm
Servos: tbd
Receiver: tbd but probably spektrum 6210
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Old Mar 24, 2012, 07:19 PM
Tim Lampe; Hobbico R&D
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Champaign, IL
Joined Dec 2009
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Congratulations and thanks amagad.

I've flown the Rifle dozens of times on the ARC 28-37-2 with 4.5 x 4.1. The only thing I am compelled to remind you of it's over the 300W limit specified in the manual. However, as I said, I have dozens of flights on a stock airframe Rifle with this setup and am also flying two other Rifles with the 28-35-3900 Ammo at around the same watts as your ARC and going fine. You may want to start out on low rates.

Visit my blog for ways to make a few simple improvements.

Keep us informed of how it is going and post some images.

Tim
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Old Mar 25, 2012, 12:33 AM
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Alberta,Canada
Joined Nov 2009
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Quote:
Originally Posted by stanordave View Post
Well it flew fine w/the Ammo today. Launching it has gotten waaaay easier. Either my arm has gotten stronger or I have a better setup than earlier! Maybe its just better technique. Hardly loses any altitude on the throw. The dual aileron setup may come in handy when I start using 4 cells to keep the CG close (if a decent size 4s fits!)

for now, I'll go fly while ya'll go work

cheers,
Mike
I run a 4s 1000 50c in my rifle,and I have not removed the inside wood support rib.
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Old Mar 25, 2012, 04:08 AM
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Sydney Australia
Joined Aug 2009
395 Posts
3 more flights today. I really love this little plane. I tried using the landing method that a number of guys mentioned on this thread by flaring gentle until they run out of up elevator but the approach i use now is to slow it as much as possible but then fly it onto the ground as smoothly as possible keeping the wings level. I have installed the landing skids on each wing tip to help stop catching a wing tip.
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