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Old Nov 12, 2011, 08:16 PM
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Granby, CT, USA
Joined Jan 2001
937 Posts
Help!
Fw 190 power requirement?

I'm in the midst of finishing up a 58-inch-wingspan FW-190 built from Model Aviation plans, originally designed to be flown with a .40 glow motor. I don't have a comfortable idea of how much power I'll need to comfortably fly this thing realistically (meaning no screaming vertical climbs after a five-foot takeoff roll).

Any advice will be appreciated.

So far, the power system I originally intended to use has been tested to turn a 12x8 prop on 16 NiCd cells at 20 amps. This works out to 400 watts. My intention is to use a 6S lithium battery. I do not know the rpm associated with that prop and battery combination. I'm hoping for 10K rpm with 22.2 volts. Going from 20 to 22.2 volts, does anyone have a guess of the increase in current?

Thanks very much. Any comments, experience, or suggestions will be appreciated.
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Last edited by PeterH; Nov 12, 2011 at 08:26 PM. Reason: clarify title
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Old Nov 12, 2011, 10:11 PM
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mistairjoe's Avatar
lake orion mi
Joined Sep 2002
921 Posts
The easy answer is an E-flight 46.Here are the specs.


Size: Replacement for 40- to 46-size glow engines

Recommended Prop Range: 12x8 to 14x10
Voltage: 14.4 to 19.2
RPM/Volt (Kv): 670


Shaft Diameter: 6mm (.24 in)
Overall Length: 55mm (2.15 in)
Weight: 290 g (10.0 oz)
Overall Diameter: 50mm (2.00 in)
Diameter: 50mm (2 in)
Length: 55mm (2.15 in)
Continuous Current: 40A
Maximum Burst Current: 55A (15 sec)
Cells: 12–16 Ni-MH/Ni-Cd or 4–5S Li-Po
Speed Control: 60A brushless
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Old Nov 13, 2011, 12:59 AM
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Kilsyth, Victoria, Australia
Joined Oct 2003
1,937 Posts
Dear Peter,
Know the plan well as I have it at home. Been a "good possible" in among my favourites. If, as I imagine, you might be hoping for around 5 -6lb I really don't think you need to go near 6S.

I flew one of the VQ 190A model on electric for a review here in Australia. At a weight of eight pounds it flew easily and with authority on 5S. Certainly stay away from the 16 Nicad cells as this will have a pack weight around 32oz and, dependant on type probably only the equivalent of a 2200 - 2600 Lipo. A 4000+ 5S lipo will weigh much less which will produce a better flyer with longer flights.

My current Miles Sparrowhawk also weighs in at 8.5lb and flies on 5S using a 5020/510 motor turning a 15 X 8 APC E prop and during flight only requires around 20 amps at very scale like flight for a racer.

Look forward to seeing your FW 190 but the best way, if you believe me, is to keep the weight down and the wing loading low. This will produce nice characteristics and pleasant landings. Can't remember the manufacturer but there is a very handy alloy spinner available suited to a FW. It is comparatively heavy being designed for IC but this helps greatly with getting the balance sorted out on a short nose plane.
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Old Nov 13, 2011, 01:40 AM
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United States, PA, Grove City
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Quote:
Originally Posted by David Hipperson View Post
Dear Peter,
Know the plan well as I have it at home. Been a "good possible" in among my favourites. If, as I imagine, you might be hoping for around 5 -6lb I really don't think you need to go near 6S.

I flew one of the VQ 190A model on electric for a review here in Australia. At a weight of eight pounds it flew easily and with authority on 5S. Certainly stay away from the 16 Nicad cells as this will have a pack weight around 32oz and, dependant on type probably only the equivalent of a 2200 - 2600 Lipo. A 4000+ 5S lipo will weigh much less which will produce a better flyer with longer flights.

My current Miles Sparrowhawk also weighs in at 8.5lb and flies on 5S using a 5020/510 motor turning a 15 X 8 APC E prop and during flight only requires around 20 amps at very scale like flight for a racer.

Look forward to seeing your FW 190 but the best way, if you believe me, is to keep the weight down and the wing loading low. This will produce nice characteristics and pleasant landings. Can't remember the manufacturer but there is a very handy alloy spinner available suited to a FW. It is comparatively heavy being designed for IC but this helps greatly with getting the balance sorted out on a short nose plane.
I gave a 50" build away to a glow flyer, as it was just too heavy for my liking in recent times. I still have the AXI 2826-12, prop, and spinner, and will probably build another sometime in life, as you said, light. This build here is motivating me to want one, as it is a favorite plane. Especially with modern high-C lipos, I agree that 6s is not needed. A 2826 10 or 12 at 58" span would be ample, even on 3s, as long as the build is not a tank.
Bill
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Old Nov 13, 2011, 02:28 AM
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Canada, ON, Owen Sound
Joined Oct 2008
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I built a Kyosho P40 Warhawk conversion using 6S a couple of years ago. I used a Scorpion 4020-14 motor, 14/7 APc e prop, 6S/5000 25C battery. AUW was 7 lbs,6ozs. Motor made 1100 watts with this setup. A 4020-16 with the same prop would make around 900 watts. Right now, Hobbyking has a listing of the 4020-16 for $79.95, half the $$ everyone else is asking.
Is this where my plane I'd run an Emp prop, 15/8/3 blade on 6S/4000 30C from a Turnigy 80A Plush Esc. The 4020's are heavy enough to help with CG (FW has a fairly short nose). If power tests prove too hot, I'd cit the prop down to 14". JM2C FWIW Doug B
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Old Nov 13, 2011, 07:31 AM
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V2rider's Avatar
USA, MD, Hagerstown
Joined Jun 2009
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Here is my first Kyosho FW-190 running the E-Flite P-46, 75amp CC ICE esc, 13x8x3 MAS prop, on a 4s 5000ma 25c pack. Lost it in June, but doing another now. This one is getting the same esc, a Himax 50-30-390kv motor turning a 14x9x3 MAS prop on 6s.
FW-190 .mpg (4 min 57 sec)
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Old Nov 13, 2011, 08:00 AM
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New Boston, Texas, United States
Joined Jan 2003
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Peter,

See my thread for power notes. I would love to see some pictures of yours. Finished and unfinished.

JIm
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Old Nov 13, 2011, 01:32 PM
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United States, PA, Grove City
Joined Jan 2011
751 Posts
I'd love to see pictures also. I'm trying to recall if this is the Peter who built and flew a really well done Guillows 190 conversion some years ago, that was built from my Guillows plans. Either way, the more 190s the better. I still have my 6 or so year old Alfa 190, which is the best all-around flying plane I have, hands down. Can't quite say that for the heavy 28" Guillows version, but it flies fine for what it is.
Bill
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Old Nov 13, 2011, 02:03 PM
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Melbourne, Australia
Joined Mar 2009
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About 120-150 watts per pound is the rule for a Warbird. And really, if you want an easy conversion, then the E-flight .46 is the way to go.

Knowing David Hipperson personally as I do, I can vouch for his opinion.

Cheers,

Hugh
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Old Nov 13, 2011, 03:45 PM
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Granby, CT, USA
Joined Jan 2001
937 Posts
Thanks to all

Folks, I'm going to make grateful noises at one time for everyone who has offered his experience and advice. Thanks very much to all of you. I have three drive systems available to me, the one I mentioned, a geared Astro 40 and a brushless motor from Common Sense.

I'm trying to do an acceptable job and getting into the air an airplane project that was partly built (fuselage framed up) and obtained from an estate, powered by a gift geared motor. I wanted to see the airplane and the motor get used, and I was hoping that they could be used together. We'll see. The airplane, covered and sealed, ready for paint, weighs 40.5 ounces. Plus motor, plus battery, finish, retracts, servos and receiver.
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Old Nov 13, 2011, 11:34 PM
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Kilsyth, Victoria, Australia
Joined Oct 2003
1,937 Posts
Dear Peter,
Like you I have an Astro 40G in my motor cupboard along with a couple of Astro 25G, and several other European brushed motors. The 40G is a great motor in terms of quality and longevity but vastly overweight compared with modern outrunners. The Astro would be much better suited to something like a large Cub style aeroplane. While I know that you will have to keep weight up into the nose it is better to control your choice of weight rather than having the bits of weight controlling you if you get what I mean.

I'm flying a Phoenix P-51 which is very similar both in size and weight to your 190. A Hyperion 3020/10 on 3S 3700 flies this quite well but space controls battery size.
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Old Nov 14, 2011, 07:36 AM
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Granby, CT, USA
Joined Jan 2001
937 Posts
Thanks

David, thank you very much for your comments, and thanks to everyone else, too. I agree that the Astro 40 is a weighty lump, but in the event that the original motor doesn't look like it will drag the model around well enough, I'll see if the model will tolerate the Astro without adding tail ballast. Otherwise, I'll move along to step 3 of my motor selection and use a brushless '.46 size' motor I bought from Commonsense last year.

All this motor choice traffic has come into play after I framed up the FW-190. At the beginning of all this, I'd been gifted with a ganged-geardrive array using a pair of Kyosho brushed motors, and soon thereafter got gifted with the Focke-Wulf project. All this being a few years ago. I was the owner of what looked to be a usable power source and a project to put it in, all for zero cash. The cheapskate side of my personality awoke and I adapted the model's engine compartment for the geared array. I've since purchased, also a few years ago, the Astro and the brushless motor, but these came along after the project got defined and the original motor array designed into the cowl area. With the passing of time motors have become extremely inexpensive, and the judgements and compromises we would have made in the past have become irrelevant. It's a different world.

Onna, no, I'm not the Peter who you helped in the past. This is my first FW-190 project.

I'll post some pictures when I can.
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Last edited by PeterH; Nov 14, 2011 at 07:43 AM. Reason: additional text
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