Phoenix Super Decathlon conversion - RC Groups
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Apr 27, 2011, 01:59 PM
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greywolfe57's Avatar

Phoenix Super Decathlon conversion

I have seen a few post on "how to" but none dealing with what I am attempting. I would consider myself to be an intermeadiate pilot having flown for about 4 yrs and observed since a kid. Thing is I don't like the foamies, just a personal thing, but am balsa from days gone by. That is why the Decathlon, 66 inch wingspan, 7lb finished weight. This plane suggested engine .46 to .50 gas. Reviews stated that engine sizes were still lacking in power and some upgraded to .60 to .75 and were pleased. Soooo, I just ordered an Exceed Power 60 400kv, 1200wt for this plane. Why I am here is hoping that the expierenced pilots could offer me some advice on matching battery to engine. I am pretty sure it is going to take a 6 cell LiPo but I am unsure of the "C" rating as well as the voltage if 14.8, 18.5 or 22.2 volts. I think it is best to do a seperate rx battery in this plane. Any suggestions would greatly be appreciated. The following specs are known but I don't know what to do with them .....

Model #: Monster Power 60 (63M55)
Kv: 400Kv
Input Watts: 1200W
Resistance: .06 ohms
Idle Current: 2.70A
Continuous Current: 40A
Max Burst Current: 60A
Cells Ni-Cd/Ni-MH: 16-24
Cells Li-Po: 5-7
Weight: 14.8 oz (420g)
Overall Diameter: 2.0 in (50mm)
Shaft Diameter: .32 in (8mm)
Overall Length: 2.55 in (65mm)

Thanks for your input and advice,

Last edited by greywolfe57; Apr 28, 2011 at 08:53 AM. Reason: wrong wingspan
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Apr 28, 2011, 08:56 AM
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greywolfe57's Avatar
Hi again all. I know I am new to the site but I really do need some help on choosing the right battery set up as I know very little about electrics. I have looked at some of the models you guys/girls are building and am humbled by the commitment shown and attention to detail. I only hope to be worthy of receiving advice from you.


Apr 28, 2011, 10:32 AM
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Ken Myers's Avatar
Looks like a 3800mAh to 4000mAh 6-cell would be about right for your 400Kv motor. You really don't need to worry to much about the C-rating. See spreadsheet below.
Apr 28, 2011, 11:29 AM
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greywolfe57's Avatar
Thanks alot for the info. Just wanting to be sure of what needs to be done so I don't have a maiden disaster or end up with a burnt up project. Thanks again.

Apr 29, 2011, 09:22 AM
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greywolfe57's Avatar
This really is a nice model from Phoenix. I did a test fit of the parts all looks good. Some wrinkles, not many and not bad at all when arrived but heat gun and paitence cleaned it right up. I will post as model progresses and again thanks for the information on the electric set-up!!

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Apr 29, 2011, 05:57 PM
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warhead_71's Avatar
I plan to use a similar motor converting a 1/6 scale Sterling Stearman ~9lbs AUW. I will be running 4x 2200mah 3S 20C lipos is series/parallel for 6S2P 4400mah 40C. I will likely use a 16x10 prop for scale. 15x8 might be more efficient for your application (lighter plane, less drag).
May 03, 2011, 10:00 PM
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greywolfe57's Avatar
I got my monsterpower 60 today, waiting on the motor mount and ESC to come in along with my servos. Cut flaps in today, I know WHATTTTTTT!!! I like to go up and do some floating and slow flying. I used the hinges installed so all I had to do was add the extra mounting platforms for the servos. I will put some pictures up next post when all the parts are in so I can show you how I am placing them and hopefully if I screw up one of you will catch it!! LOL.

On another note I have been looking at one of the Sky Fly 2.4ghz 6 channel radios. I know the saying about getting what you pay for but hey the reviews on this unit are all good and it seems that the range on the unit is extremely good as well. Any suggestions or review from anyone who has one would be greatly appreciated.

May 03, 2011, 10:30 PM
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Joespeeder's Avatar
Hey greywolfe57,

Your Monster 60 is basically an Eflite 60 equivalent. I have an Eflite 60 in a 9 1/2lb Hurricane. I also have a Scorpion 4020-16 in an ME-108 which is also an Eflite 60 equivalent.

Both of my set ups run on 4200 Hyperion 6s and a 15x10 prop. At 7lbs you wont need the 9+lbs of thrust a 15inch prop gives you.....Of course it would be fun. I would start on a 14x10 and adjust.

Now each of these motors will give you slightly different numbers but they are probably the closest three to each other I've seen. When choosing props it's good to have an idea of what the change will get you. More thrust? More Speed? Less Power?? Etc.

Here's the work sheet for my Scorpion set up which I know is VERY close on my Eflite motor also. Since your Monster motor is very close to these two this should give you a guide.

DON'T trust these exact numbers other than as as guide to test a new prop with a watt/amp meter and tach.

Write down your results and the guide will give you an idea what a change will get you. It's interesting to see how pitch or diameter will change things in ways you didn't expect.

Some times its better to get more pitch on a smaller prop sometimes it goes the other way. I'm guessing a APC 14x10E is what you want. At least that's where I'd start.

4020-16, 6s, APC 14x7E - RPM 8173, Pitch Speed 54mph, Thrust 102.4oz, Amps 28, Watts 636

4020-16, 6s, APC 14x8.5E - RPM 8059, Pitch Speed 65.9mph, Thrust 122.7oz, Amps 34, Watts 765

4020-16, 6s, APC 13x10E - RPM 8006, Pitch Speed 75.8mph, Thrust 112.8oz, Amps 37, Watts 824

4020-16, 6s, APC 14x10E - RPM 7928, Pitch Speed 75.1mph, Thrust 125.1oz, Amps 41, Watts 911

4020-16, 6s, APC 15x8E - RPM 7897, Pitch Speed 59.8mph, Thrust 144.5oz, Amps 43, Watts 946

4020-16, 6s, APC 15x10E - RPM 7749, Pitch Speed 73.4mph, Thrust 159.9oz, Amps 50, Watts 1106

4020-16, 6s, APC 16x8E - RPM 7676, Pitch Speed 58.1mph, Thrust 177.8, Amps 53, Watts 1185

4020-16, 6s, APC 16x10E - RPM 7484, Pitch Speed 70.9, Thrust 192.6, Amps 62, Watts 1385

May 03, 2011, 11:18 PM
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greywolfe57's Avatar
Thanks Joe and Warhead for the input and suggestions, I can use all I can get. You guys have any picts you would share so I can get an idea of how other conversions look? Thanks again for you help. Can't wait to get this bird together and flying.

May 16, 2011, 12:42 PM
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greywolfe57's Avatar

its together now..almost

I want to thank the ones who gave me some guidance on where to look and possible solutions to what to use. I would have posted some pictures of progression of build but I was not so proud of my well kept and orderly work area . So it ended with an exceed monster power 60 400kv, 80amp esc, 4000mah 6s 22.2v lipo, 5 cell nimh 6v(rx). Flysky 6ch tx & rx range tested to 1/2 mile. I added flaps, simply cut them out of the ailerons. Installed individual servos on all flap and ailerons. I still have to figure out where I am going to place the lipo and how to make access without having to pull the wing everytime. I have an idea . Here are some picts.
May 16, 2011, 12:49 PM
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warhead_71's Avatar
For battery location, see this:
May 19, 2011, 01:50 PM
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greywolfe57's Avatar
thanks man but the set up for my plane makes it way to nose heavy. the monster 60 is heavy enough and with the 6s battery pack up front I would have to have a brick on the tail....LOL>...i believe that an access on the bottom is going to have to be done. the balance point puts the battery just under the servo mounts for the elev. and rudder which is about 8 inches behind the firewall. i think in this case i will use hinges and a couple of latches instead of magnets as the battery is fairly heavy and if, and i say if very gingerly, something happens and the battery comes loose it would push magnets open easily. thanks again for the link and idea and i believe it would have worked if the motor wasn't so heavy.
May 19, 2011, 01:59 PM
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I am wondering if a monster power 46 on 4s would be enough to power this plane. I have that setup on hand. Would definitely be a lighter setup.
May 19, 2011, 02:21 PM
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greywolfe57's Avatar
I looked at the MP 46 and did a lot of research both glow and electric and from what I saw the 40 thru 50 glow fell just short of power in climbing and some light acrobatics. The electrics being very close in conversion ratings left me thinking, that is where I get in trouble sometimes, thinking..... So looking again at reviews and seeing the the most used glow was a tiger 75 I felt that the 60 would be the motor for me. Granted I am looking to fly slow and not many acrobatic moves except the ones needed to keep me from crashing....LOL. But to answer you yes I do believe that the Power 46 would handle the plane but this build is nearing 9lbs and it was said to build out at 7. The pilots at the AF all feel either motor would work as well but opted for the 60 too. Man when converting so many things to look at and such great ideas from everyone here too and I really appreciate you all.
May 19, 2011, 02:53 PM
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Harry H's Avatar
Greywolfe, I don't know if this would be an option for you, but I have a similar plane where I remove the windshield to access the battery. Same motor and battery that you are using. Taking the wing on and off was just way too much work.


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