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        Discussion Great Planes Cherokee .40-.56 ARF 60"

#1 phyxer May 16, 2008 01:50 PM

Great Planes Cherokee .40-.56 ARF 60"
 
I picked this ARF up yesterday at the Hobby Shop and it really looks nice! VERY strongly built (typical for gas planes that get converted to electric). No wrinkles in the covering. Should go together very quickly. Looks like an extremely easy build. Still shopping for the power system as I want to use a 4S setup apposed to the recommended 5S setup. AUW is supposed to be between 6.75-7.25 pounds. Seriously considering the Motrofly 2820-950KV motor and 11x7 prop with 4S 4000mah batteries. I think it should be a perfect touch-and-go airplane that will perform mild aerobatics as well! Whatcha ya'll think? :p

Troy

#2 phyxer May 18, 2008 02:14 AM

Am I the only person on the face of the earth that likes this model? Oh well, I unpacked it and went over all the joints I could get to with CA tonight. Upon further serious inspection I discovered that my orginal analisys was correct.....this thing is built STOUT and true! I can't wait for my servos and motor to come in so I can put some batteries through it! :p

Troy

#3 fas350z May 18, 2008 06:57 AM

cherokee
 
I picked mine up last week. Real nice kit. Im going with a 4120 AXi on 4 or 5 s.
I like how the whole top hatch comes off for battery access. Uses full size servos, so I will have something to use all my spektrum DS821's in.

#4 killerstick May 22, 2008 02:34 PM

I have one also and starting the build this weekend. Using the same setup as my Great Planes Revolver.

I think it's very nice plane for the money, since tower has all the good coupon deals. They sold out of the 1st batch very fast.

#5 phyxer May 29, 2008 09:45 AM

Ready for Maiden
 
Well, I finally got it finished and ready to maiden. My AUW is 6 pounds 1.5 ounces. I have an E-Flite Power 32 with a Turnigy 60 amp ESC with 4S 4000 mah batteries turning an 11x7 prop. Watt meter say I'm pulling 56 amps and putting out 570 watts. Should be enough to fly it fairly well. There won't be any hovering with it though! :p On a side note, there is no way in the world that this model can be built by a normal human in 4 to 6 hours as the manual says. It is an easy build but there is a lot time required doing all the drilling and mounting. It is a gorgeous airplane and I am excited about getting it in the air. Well worth the money as far as how strong and well built it is. Hopefully it flies as good as it looks! :p

Troy

#6 jrb May 29, 2008 11:19 AM

FYI: http://www.rcgroups.com/forums/showp...28&postcount=5 .

Quote:

Originally Posted by Dr Kiwi

"Have an E-Flite Power 32 with a Turnigy 60 amp ESC with 4S 4000 mah batteries turning an 11x7 prop. Watt meter say I'm pulling 56 amps and putting out 570 watts. Should be enough to fly it fairly well."


Well, Jim,

This particular example is fraught with difficulties: The E-flite Power 32 is rated for 42A cont. If he is pulling 56A on 4s and seeing 570W on the Wattmeter he is down to 10.18v (2.55v/cell!) - that will kill 'em in a hurry. Of course, he is confused by saying "putting out" 570W - he is taking in 570W and "putting out" maybe 400W.

At 56A, his pack (let's say 80% of 4000mAh) will last him ~3.4 minutes.

I'm afraid that I cannot go along with this habit of taxing every component to the limit or beyond - heck, I have an 2.5cc diesel Oliver Tiger III, bought second-hand in 1965, used extensively for C/L combat, and which is still in good running order!

Cheers, Phil


#7 gouda May 29, 2008 11:40 AM

No,, you're not the only one. How about some pics?

#8 phyxer May 29, 2008 12:21 PM

I'll try and get some pics this evening of the finished bird. It really is a gorgeous plane. Great Planes got this one right I believe. In an attempt to provide more info on my now "contested" power system, here are Horizon's posted specs on my Power 32 motor"

Specs
Type:Brushless Outrunner
Size:Replacement for a 30- to 32 size glow engine
Bearings or Bushings:Ball Bearings
Wire Gauge:14
Recommended Prop Range:11x7 to 14x10
Voltage:12 - 16.8
RPM/Volt (Kv):770
Resistance (Ri):.02 ohms
Idle Current (Io):2.40A @ 10V
Continuous Current:42A
Maximum Burst Current:60A (15 sec)
Cells:10-14 Ni-MH/Ni-Cd or 3-4S Li-Po
Speed Control:60A Brushless
Weight:200g (7.0 oz)
Overall Diameter:42mm (1.70 in)
Shaft Diameter:5mm (.20 in)
Overall Length:50mm (1.90 in)
Needed to Complete
60A Brushless ESC
3S - 4S Li-Po or 10 - 14 Cell Ni-MH/Ni-Cd
11x7 to 14x10

As you can see, I have exceeded NOTHING! I have no intention of spending any notable time at WOT. I got this plane to be soley a sport flyer to have fun flying a box pattern doing touch and go's with. :p

Troy

#9 jrb May 29, 2008 12:56 PM

Quote:

Originally Posted by phyxer

Discussion - Great Planes Cherokee .40-.56 ARF 60"

Would you use a .32 glow?

#10 phyxer May 29, 2008 01:04 PM

jrb, I honestly have no clue as to what "non-electric" motor I would use. I have only ever flown electric and the only thing I know about gas is that it is loud and smelly. I understand your question as it refers to the electric motor's equivelant in glow, but I have found that most glow to electric conversions end up lighter (as this one did) than their glow counterpart so you can spec it for a lighter setup which is what I did. I will let ya'll know the good, the bad and the ugly once I maiden it! :p

Troy

#11 jrb May 29, 2008 01:16 PM

Bol!

#12 Ed Lyerly May 29, 2008 01:57 PM

I don't agree that "most" electric conversions (especially ARF's) end up lighter than the "glow" setup the plane is specked for. My experience is just the opposite. I'm not saying it can't be done ..... I'm saying that would be the exception , not the norm.
Also, in looking at the numbers from the E Flite 32 on 4S with a 11x7 prop ..... something is wrong. On a good 4S pack this motor should pull about 40 amps turning a 11x7 APC-E prop. If it is pulling 56 ..... then something is wrong ... as that would be more of what I would expect from a 5S pack.
Ed

#13 MustangAce17 May 29, 2008 10:18 PM

Troy,if you run that 32 at 56 amps it will fry in a heartbeat,eflite motors can be slighty pushed with plenty of cooling,i've done it BUT not THAT much! This plane needs a 46. AND you HAVE exceeded the 42 amps in the specs. I've had my hands on this plane and a 32 is gonna be mediocre at best,especially since it won't last long.

#14 phyxer May 30, 2008 09:19 AM

I agree that I CAN exceed the continuous rating of 42 amps when I hit WOT. But the specs also state that the motor can take BURSTS up to 60 amps not to exceed 15 seconds so as long as I stay at 42 amps or below for continuous use and don't stay above 42 amps for longer than 15 sec bursts and I don't ever go above 60 amps then NO, I HAVE NOT EXCEEDED ANY LIMITS! Now, as to Mustang's comment on needing a larger motor to be happy with this plane, that may be so, I will let everyone know once I get to maiden it. It is way to windy here for the last couple of days. Maybe this weekend I hope! :p

Troy

#15 jrb May 30, 2008 09:29 AM

Check the temp (are they hot?) of the motor, batteries, and ESC post flight!


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