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        Discussion Giant Scale Focke-Wulf Fw 190 ARF

#1 nippaero Sep 09, 2012 01:13 PM

Giant Scale Focke-Wulf Fw 190 ARF
 
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Is anyone else eyeballing this one for electric conversion? The built in hatch on top looks perfect for accessing batteries.

Been thinking about a P-51 on 12S but this may sway my decision. It's due sometime in October.

Here's Dans original al thread on the FW190. http://www.rcgroups.com/forums/showthread.php?t=1736958

#2 jollyroger Sep 09, 2012 01:32 PM

Specs please.

#3 Thrawn150 Sep 09, 2012 09:05 PM

I like it alot, but with just having finished my H9 P-51D 1.50 conversion it will be a few years for me. Hatch looks great, get electric retracts and you are all set yo use the hatch for batteries.

#4 nippaero Sep 09, 2012 10:16 PM

Specs here

http://www.towerhobbies.com/products.../topa0706.html

#5 jollyroger Sep 10, 2012 09:15 AM

Well, you're going to need at least 110-125 watts/lb here. probably use a 12S pack. As this plane was designed for a 50-55CC gas, I made a couple calculations using a Hacker A60-18L/12S pack and 24X12 APCE prop produces around 3627 watts in and 3174 watts out at 79A, 525 oz. thrust.
Scorpion 5545-150: 12S pack ,24X12 APCE prop, 83 amps, 3674 W. in, 3061 W out, thrust: 513 oz.
As you know these figures will vary, I used Scorpion calc and E calc to check out the performance outcomes of these two motors.
There are of course other motor brands out there that may be able to do the job, albeit not as efficiently. There are a few Axi's available that should do the job as well.
There are a number of cheap outrunner motors available but if it were my choice I would rather not use them. They are unreliable, inefficient and not well made, but they are cheap.
As expensive as that model is, I would not scrimp on either motor speed control or batteries. You certainly wouldn't use cheap servos or one of those cheap receivers from H.K. either.
How ever, figure the cost of a decent 50-55 CC gas engine. There are lots of very inexpensive one available and some high end ones sch as Desert Aircraft.
Anyway, this is what you're going to need as far as power is concerned. There are some who will disagree but this is only just a suggestion.
Good luck

#6 kahloq Sep 10, 2012 08:00 PM

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There are cheaper alternatives to the Hacker and AXI motors and Im not referring to stuff from hobbyking like the rotomax 50cc or rotomac 100cc electric motors.
Ive got the ESM fw-190 dora9 and its at 82.5" wingspan plus fiberglass fuse compared to this TF one at around 87" all built up balsa...so it'll weigh less then my D9 which much heavier Sierra Giant scale retracts then those half cheapy robarts in the TF.

My motor is the 65cc rimfire which is capable of 7500 watts on 15s.....but most people run them on 12s at around 4000-5000 watts depending on the plane.

They work just fine and are considerably less expensive.

Ive got a 21x14 prop on my plane but also have a 23x12. The motor is capable of turning 26x12

The 50cc rimfire has already been proven in the larger esm me-109G which is 87" wingspan and flies that plane with ease.

#7 nippaero Sep 10, 2012 09:55 PM

Any thoughts on spinning a 3 blade prop with that setup?

#8 kahloq Sep 10, 2012 11:01 PM

Yes...the rimfire 65cc on 12s can spin a 26x12 3 blade prop. I have a 20x14 Biela currently, but am also thinking about picking up a 24x12 3 blade for static looks on the ground plus being able to use it to fly. I want to get the maiden out of the way first on a 2 blade though.

#9 nippaero Sep 11, 2012 05:51 PM

It looks like electrifly posted some pictures of this setup on their Facebook page.
https://www.facebook.com/electrifly

#10 kahloq Sep 11, 2012 07:45 PM

Would be nice if they showed a flight report, but that 23x10 listed seems a bit low in pitch fir such a low kv motor, even on 12s.

max speed using a 10 pitch on 12s is 75mph, but that doesnt even account for motor load of the prop or drag of the airframe. Usually you lose 15% of the static max. so that would only give a real world top speed of 64mph

A 12 pitch would yield 90mph static no load and 77mph accounting for drag and motor load. Amps will go up of course.

A 14 pitch(which is what ive got) would yield a static max of 105mph and a realw orld flying speed of about 90mph. Yes amps would be even higher(except my diameter is smaller then then 23x10. Mine os a 21x14.

Having that 26mph difference means I dont have to fly near full throttle all the time plus it wont look like a dog in the air or as putsy slow as a trainer cinsidering how big these planes are.

Anyway...IU prefer speed capability(even if I dont use it all the time) over slow flying and maybe extend the flight 1-2mins.

#11 nippaero Sep 11, 2012 07:53 PM

I hope they post their findings. How does a three blade prop affect these figures. In general are the less efficient? Thanks for the data BTW. I think TBM has a scale three blade prop.

#12 kahloq Sep 11, 2012 10:44 PM

3 blade will load the motor up more. It is somewhat less efficient too, but not a massive amount.

Basically....if you have a 24x12 2 blade, and a 24x12 3 blade, the two blade will fly the plane faster. There's less mass for the motor to spin and less turbulence produced.
On the other hand, the 3rd blade on a 3blade prop adds more thrust, but due to the increased turbulence, the work the prop is doing is less effective.
So a 24x12 3 blade basically would be comparable to a 25x11 2 blade.

#13 buzzltyr Sep 16, 2012 05:54 PM

Hobbico flew this all three days at NEAT this weekend during the noon demos. 65cc Rimfire and 12S. Flew beautifully. Plenty of vertical capability. Flew both very fast and slowed down nicely. Was flown mostly in a scale fashion.

Mark

#14 nippaero Sep 18, 2012 09:56 PM

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Thanks for the heads up. There are quite a few pictures of it over in the NEAT photo thread. Here's a few.

#15 super kupfer Sep 20, 2012 01:36 AM

Quote:

Originally Posted by nippaero (Post 22771820)
Thanks for the heads up. There are quite a few pictures of it over in the NEAT photo thread. Here's a few.

I know its a FW190 thread but I cant help notice a real nice looking Giant size Revolver.


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