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Old 04-02-2011, 02:26 AM   #1
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Default Has anyone converted a CMP Cessna 182 to electric?

This is my first post so first things first; Hi!

I am new to RC planes and just finished my first build, an EP 72" J3 Cub, it flies great and I love it!

So I just bought an ARF CMP Cessna 182 (82.7" wingspan) which is designed to use a gas engine but I want to build it as an electric.

I would also like to set it up using my existing 5S batteries because I already have several that I use with the Cub (and my heli), I'm just not sure how or what motor to use.

Can anyone advise me on the best EP setup for this model, or if its even possible?

Thanks!
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Old 04-02-2011, 03:02 AM   #2
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Welcome to Wattflyer, What Flyer.

I have been flying this for about 6 years now. Love it. This plane taught me how to fly in a scale manner. It loves coordinated turns. Bank and yank is not your friend here!




Ive got a AXI 42 series motor in it (cant see the other number) and a 80 amp controller. Performance is more than scale, but that keeps me out of trouble, and I'm not on the throttle more than I need.


(P.s, see the field behind me? check it out in RealFlight expansion pack 8 http://www.realflight.com/exppack8.html )

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Old 04-02-2011, 05:59 AM   #3
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Originally Posted by What Flyer View Post
This is my first post so first things first; Hi!

I am new to RC planes and just finished my first build, an EP 72" J3 Cub, it flies great and I love it!

So I just bought an ARF CMP Cessna 182 (82.7" wingspan) which is designed to use a gas engine but I want to build it as an electric.

I would also like to set it up using my existing 5S batteries because I already have several that I use with the Cub (and my heli), I'm just not sure how or what motor to use.

Can anyone advise me on the best EP setup for this model, or if its even possible?

Thanks!
Can't go wrong with a Hacker A60-16M motor with a 19X12 APC-E prop and a Castle Creations HV ICE 80 Amp ESC. Nope, not cheap, but these motors are real power houses, very well made, with high motor efficiency. It's threaded steel prop shaft is about 5/16 inch diameter. Power wise, this motor has the same (or maybe even slightly more) horses as a 30 cc gasoline engine. Mine pulls about 65 Amps, running 2400 watts full throttle. That's about 3 horsepower. http://www.aero-model.com/Hacker-Brushless-A60-16M.aspx

I've got a half dozen Hacker motors ranging from an A30, A40, three A50 series and the A60. Most of them are three years old, and still perform as when they were brand new. Two of the A50 motors have over 200 flights on them.

Thread on Hacker A60-16M motor vs gas/glow engine performance
http://www.wattflyer.com/forums/showthread.php?t=58035

Thread on 70 size glow engine conversion to electric
http://www.wattflyer.com/forums/showthread.php?t=45222

I've got my A60-16M motor and its 19X12 APC-E prop running on 12S2P A123 cells, close to your 10S Lipos. This motor will turn that 19 inch prop at around 6500 RPM, just right for that Cub. Running that motor at full power in my workshop is a little scarey. And the prop blast blows everything all over the place. Even rugs 5 feet downwind go flying.

Even so, I've got my 16M in a Extra 330 with 78 inch wingspan, 1200 square inch wing that weighs in at 17 pounds. It hauls that model around with authority. Problem is, around SE Wisconsin, only had one day to fly it. Been to cold, where highest temperature has only been 40 degrees for the past two weeks.
http://www.wattflyer.com/forums/showthread.php?t=59273

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Old 04-02-2011, 08:18 PM   #4
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Yeah that is a bit pricey but I guess you gotta pay to play, right?

So would I run my 2 5s batts in series? I'm also wondering how to get the them in and out of the fuse without too much disassembly. My first thought is to leave the side windows out (or maybe hinge them?) for access.

Any thoughts on this?

Also need servo recommendations.

Thanks for your help!
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Old 04-02-2011, 08:22 PM   #5
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Originally Posted by What Flyer View Post
My first thought is to leave the side windows out (or maybe hinge them?) for access.

Any thoughts on this?

Make the front windshield removable.
I added a plywood doubler under the fiberglass at the windshield corner, and I just remove the front windshield. 2 little screws works fine. Dont overtighten, and its worked for a long time.

I left the side windows out for ventilation and access.

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Old 04-02-2011, 08:24 PM   #6
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Originally Posted by Nitro Blast View Post
Make the front windshield removable.
I added a plywood doubler under the fiberglass at the windshield corner, and I just remove the front windshield. 2 little screws works fine. Dont overtighten, and its worked for a long time.
Cool, do you mind posting a pic of your setup? I'm not sure I'm visualizing it correctly.
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Old 04-02-2011, 09:12 PM   #7
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Originally Posted by What Flyer View Post
Yeah that is a bit pricey but I guess you gotta pay to play, right?

So would I run my 2 5s batts in series? I'm also wondering how to get the them in and out of the fuse without too much disassembly. My first thought is to leave the side windows out (or maybe hinge them?) for access.

Any thoughts on this?

Also need servo recommendations.

Thanks for your help!
Yup, you'd run your 5S batteries in series. FYI, minimum battery capacity would be perhaps 4000-5000 milliampere hours. This motor can pull 60 amps at full throttle. As for expensive motors, I've read to many stories about some of those lower cost motors having bearing problems after a few dozen flights, magnets coming loose after a few dozen flights. The Hacker A40 and larger series motors use four ball bearings. Three on the motor shaft, and a forth large diameter ball bearing to support the "Bell" end of the rotating magnet structure. That forth large diameter bearing absolutely eliminates the possibility of the rotating magnet bell twisting and hitting the stator, possibly taking magnets with it.

I had a 1/4 scale Piper Cub some 12 years ago, simply did not put in the windows on the passenger side for access to the batteries. This thing used 38 Sub "C" 2400 Milliampere hour Nicad cells.

Did a lot of flying with it, finally sold the model to a local guy, sold the Astroflight Geared 90 motor on Ebay.

As for servos, my Extra 330 uses 7 servos, four on the ailerons, two on the elevator, one on the rudder. Servos used are Hitec 645MG's. I've measured the maximum current pulled when all transmitter sticks are moved in all directions. Peak receiver current came out to 14 Amperes!

Be certain to use a receiver battery pack suitable for this. I'm using a Castle Creations 10 Amp uBEC, along with a two cell A123 2300 Mah battery pack as backup. Take a look at the attached. In my case the primary battery is the Castle Creations 10 Amp uBEC, backup battery is a two cell 2300 Mah A123 pack. I used two schottky diodes for isolation between the A123 battery and the uBEC.
http://www.wattflyer.com/forums/showthread.php?t=58989

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Old 04-02-2011, 09:26 PM   #8
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Originally Posted by What Flyer View Post
Cool, do you mind posting a pic of your setup? I'm not sure I'm visualizing it correctly.


No problem. From this angle you can see the block on the other side, that holds the screw. Only thing holding the windshield on are those two screws. They come out each flight.




on a side note, I left the rear plastic out for vent, not the side windows as I earlier said.

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Old 04-02-2011, 11:18 PM   #9
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Thanks DennyV, thats good info. can the bearings in the hacker be replaced?

and NitroBlast, I like that setup... may even try to adapt a quick-release fastener instead of the screws or something.

btw did you have to trim some "dash board" out? mine looks a little diff than yours.

I gotta say I am sooo hyped on this thing I can hardly stand it!
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Old 04-02-2011, 11:59 PM   #10
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Originally Posted by What Flyer View Post
Thanks DennyV, thats good info. can the bearings in the hacker be replaced?
Yup
I "ball dented" the bearings in my Hacker A40-12S motor several years ago when the ailerons on my model came completely out of the model, just hanging on with the servo pushrod. (Model only had 3/16 inch glue area for the hinges! Bad design)

Called Hacker in Arizona, ordered new bearings and motor shaft, installed them myself.

Not a job for someone without a lot of experience though. To easy to damage the windings when pulling that big diameter ball bearing on the bell end of the motor.

On the other hand, they do repair these motors in the USA, at least two years ago anyhow.

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Old 04-05-2011, 07:47 PM   #11
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I have already converted the CMP large cessna 182 to electric. I used an E-flite power 160, hobby king 120 ESC, and two 4s in series for 8s, and 4000 mah 30-40C batteries. It flies great. Plenty of power.
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Old 04-05-2011, 08:42 PM   #12
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Originally Posted by UGLYPUG View Post
I have already converted the CMP large cessna 182 to electric. I used an E-flite power 160, hobby king 120 ESC, and two 4s in series for 8s, and 4000 mah 30-40C batteries. It flies great. Plenty of power.
Is the HK120 ESC "high voltage" capable?

I'm planning to run 10s 6600mah (2x 5s 3300mah) so I want to be sure I dont run it too hot.

Also I think its gonna weigh in @ 10lbs (82" wingspan), and I'd rather have too much power rather than too little.

Thanks!
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Old 04-05-2011, 08:48 PM   #13
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The HK 120 esc will handle 12s, so 10s should not be a problem. I went overboard on power too so I would have plenty of power, and extra ESC capability also. And yes, it is HV.
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Old 04-06-2011, 12:25 AM   #14
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Originally Posted by kyleservicetech View Post
Can't go wrong with a Hacker A60-16M motor with a 19X12 APC-E prop and a Castle Creations HV ICE 80 Amp ESC.

I've got my 16M in a Extra 330 with 78 inch wingspan, 1200 square inch wing that weighs in at 17 pounds. It hauls that model around with authority. Problem is, around SE Wisconsin, only had one day to fly it. Been to cold, where highest temperature has only been 40 degrees for the past two weeks.
DennyV, I just noticed that you may have misunderstood me and thought that this motor/esc/prop is for a Cub. If so, I just wanted to make sure that you realized its for a Cessna 182 with 82" wingspan, @ 10-11lbs.

Will it still be enough? Also, I'd rather not use a batt pack for the rx/servos so what would you recommend for a BEC?
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Old 04-06-2011, 03:14 AM   #15
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Originally Posted by What Flyer View Post
DennyV, I just noticed that you may have misunderstood me and thought that this motor/esc/prop is for a Cub. If so, I just wanted to make sure that you realized its for a Cessna 182 with 82" wingspan, @ 10-11lbs.

Will it still be enough? Also, I'd rather not use a batt pack for the rx/servos so what would you recommend for a BEC?
Yup, realize it is for a Cessna 182.

FYI, I just got the first three flights on my Hacker A60-16M, 12S2P A123 pack, 19x12 APC-E prop, 78 inch wingspan, 1200 square inch Extra 330 model today.

Winds were about 12 MPH, temperature about 45 degrees.

Holy Crap, that motor has power! It hauls that 17 pound airplane up at 60 degrees and keeps on going. The Castle Creations ICE database shows that the maximum power is 2650 watts, turning that 19X12 prop at 6500 RPM. This setup had no problem flying the model running at about 600 watts while in flight. I limited my self to 4 minute flights, which took about 1300 Mah out of the batteries 4000 Mah capacity.

Maximum current pulled by that Hacker was 69.5 Amps, the motor was cold on landing. (It was only 45 degrees F though)

So, I suspect it will fly your 10 - 11 pound Cessna 182 very well.

As for uBEC's, I'm using a standard 10 Amp Castle Creations unit. NOTE that this uBEC is only rated for 6 Series Lipos. What I did is wired two 6S2P A123 packs in series, and connected the uBEC to ONLY ONE of the battery packs. Also have a backup receiver battery that uses two series A123 cells.

Take a look:
http://www.wattflyer.com/forums/showthread.php?t=58310

IMHO, if you're flying giant scale models, dual receiver batteries is a requirement. What I did was configure the CC uBEC for 6.5 Volts DC, and put a pair of 2 Amp silicon diodes in series with the two cell A123 pack. That prevents the A123 pack from interfering with the CC uBEC.

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Old 04-06-2011, 03:06 PM   #16
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Originally Posted by what flyer View Post
dennyv, i just noticed that you may have misunderstood me and thought that this motor/esc/prop is for a cub. If so, i just wanted to make sure that you realized its for a cessna 182 with 82" wingspan, @ 10-11lbs.

Will it still be enough? Also, i'd rather not use a batt pack for the rx/servos so what would you recommend for a bec?
just to let you know, i can get over ten minutes flight times with my set up. Seems the bigger motor just lopes along with this plane, and doesn't suck the batteries as fast as the higher rpm/volt jobs. I love it,, but, had a little accident and it is out of service for a while,,, messed up the right horizontal stab,,
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Old 04-06-2011, 03:54 PM   #17
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Originally Posted by UGLYPUG View Post
just to let you know, i can get over ten minutes flight times with my set up. Seems the bigger motor just lopes along with this plane, and doesn't suck the batteries as fast as the higher rpm/volt jobs. I love it,, but, had a little accident and it is out of service for a while,,, messed up the right horizontal stab,,

Can't argue with success! As in "if it ain't broke, don't fix it".

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Old 04-06-2011, 05:03 PM   #18
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Originally Posted by kyleservicetech View Post
Can't argue with success! As in "if it ain't broke, don't fix it".
Well it sounds like it IS broke, ha ha! Get that thing back in the air soon, UGLYPUG!

So I ended up going with the e-flight 160 and a CC120HV ESC.

I will also be using a Hyperion BEC but would like to have a batt backup, too. What would be the best way to configure such a setup?
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Old 04-06-2011, 07:48 PM   #19
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Originally Posted by What Flyer View Post
Well it sounds like it IS broke, ha ha! Get that thing back in the air soon, UGLYPUG!

So I ended up going with the e-flight 160 and a CC120HV ESC.

I will also be using a Hyperion BEC but would like to have a batt backup, too. What would be the best way to configure such a setup?

Question:
Is the output voltage of the Hyperion BEC adjustable? If so, this will work.

Pick up a 5 cell Nih, or a 2 cell A123 pack. (Do not use a 4 cell pack) Pick up two silicon diodes from Radio shack, and put them in series with the red wire of the on-off switch harness for the backup battery pack. (The diodes prevent any interactions between the uBEC and the backup battery) Normally one diode would be enough, but I ran into the backup battery sending power to the receiver on occasion. Be sure to properly protect the solder joint to the diodes with a few pieces of shrink tubing.

Then, adjust the voltage output of the uBEC so the backup battery is not delivering any current while flying. I've adjusted the output voltage of my Castle Creations 10 Amp uBEC to 6.6 Volts DC. It's simple to check. The receiver should work on either the uBEC, or the backup battery. And, of course it should work with both battery inputs switched on. Check the battery voltage with the uBEC on with the backup battery off. Then compare this to the receiver voltage with the uBEC off, and the backup battery on. The receiver voltage should drop perhaps 3/4 volt or so, indicating the backup battery voltage is less than the uBEC. This should be done with the battery fresh off the charger.

I've plugged in my uBEC into the standard battery input of my Spektrum AR7000 receiver, and plugged in the backup battery into any unused servo connection. I used the gear servo input. If you've run out of servo inputs on your receiver, put a "Y" harness on the throttle connector, run one to the ESC, the other to the backup battery. This does provide a little redundancy with the two different DC power connections to your receiver.

Be sure to charge that backup battery before any flying sessions.

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Old 04-07-2011, 07:02 PM   #20
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Yes, the output is adjustable from 5-6v.

btw I got the CC110hv, not the 120 as I posted above.

I have a batt pack that came with my DX7 but I'm not sure of the specs on it. (I'm away from home at the moment) I'd like to use that if possible.

Thanks for the help!
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Old 04-08-2011, 12:48 AM   #21
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Originally Posted by What Flyer View Post
Yes, the output is adjustable from 5-6v.

btw I got the CC110hv, not the 120 as I posted above.

I have a batt pack that came with my DX7 but I'm not sure of the specs on it. (I'm away from home at the moment) I'd like to use that if possible.

Thanks for the help!
If you're referring to the standard DX7 receiver battery, that is a 4 cell battery. The web sites refer to many 2.4 ghz receiver re-boots resulting from voltage dips on the receiver when flying giant scale models with that 4 cell pack. IMHO, those "Pen lite" sized Nih batteries should only be used in perhaps 5 - 6 pound models and smaller.

In my opinion, giant scale models should use at least a five cell Sub C type Nih battery, or a two cell A123 2300 Mah battery. And dual supplies should be used for giant scale models. Those 2300 Mah A123 cells can put out 25 Amperes (Continuously at that) with absolutely no problem.

The seven Hitec 645MG servos in my Extra 330 (17 pounds, Hacker A60-16M, 19X12 APC-E prop, 12S2P A123 cells) have a measured peak current of 14 Amperes when all transmitter sticks are moved in all directions. That 14 Amperes is far above the capability of any Nih type "AA" battery pack.

Problem is, a pair of 2400 Mah Sub C Nih battery packs is going to weigh in at about a full pound of weight. A pair of A123's will be about 1/2 of that, and one A123 plus a uBEC will be about 6 ounces.

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Old 04-17-2011, 07:21 PM   #22
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Ok, so i finally got my motor (eflight 160), esc (castle 110 HV) and bec (hyperion HP-ticool) installed and fired it up.

Everything seems to work as it should but i am a bit concerned about the big spark i'm getting when i connect the batts (2x 5s 3300mah). Is this normal for a HV system or could there be something out of whack here?

btw the plane weighs @ 14lbs with motor and batts but i had to trim my prop a bit because of ground clearance issues. It was 18" and now it 17", do you think this will be a problem?
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Old 04-17-2011, 10:30 PM   #23
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Originally Posted by What Flyer View Post
Ok, so i finally got my motor (eflight 160), esc (castle 110 HV) and bec (hyperion HP-ticool) installed and fired it up.

Everything seems to work as it should but i am a bit concerned about the big spark i'm getting when i connect the batts (2x 5s 3300mah). Is this normal for a HV system or could there be something out of whack here?

btw the plane weighs @ 14lbs with motor and batts but i had to trim my prop a bit because of ground clearance issues. It was 18" and now it 17", do you think this will be a problem?
Yes, all of the ESC's have what's called capacitors connected directly across the DC input of the ESC. These capacitors knock off any voltage surges that take place because of what's called the inductance of the battery wires. This inductance can cause voltage spikes nearly twice the battery voltage.

But, those same capacitors take a LOT of current for a fraction of a millisecond when you power the ESC up. And that "Lot of current" will cause arcing on the connector when you plug it in.

Not really a problem, but it will eventually lead to erosion of your battery connectors terminals, so kind of keep an eye on that. FYI, I've got a model with 12S2P A123 packs, and the spark you get when the Castle Creations 80 Amp HV ESC can be heard from 20 feet away.

As far as the prop goes, make certain it is well balanced. Also note, removing an inch off of the diameter of the prop will make a significant decrease in watts input to the motor. That decrease in watts is related to the ratio of the prop's original diameter and the new diameter raised to the third power. (LOL, ask your fifth grader!) That's about 20% difference or so.

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Old 04-18-2011, 12:30 AM   #24
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Good to know.

So what does "significant decrease in watts input" do? more heat for the esc or?
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Old 04-18-2011, 02:16 AM   #25
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Originally Posted by What Flyer View Post
Good to know.

So what does "significant decrease in watts input" do? more heat for the esc or?
Good question.

Reducing the diameter of the propeller on an electric model will significantly reduce the "horsepower" on the propeller shaft, and will reduce the performance of your model.

If your model is well overpowered to begin with, you won't notice much difference. But if the model is just able to get into the air, it could make a big difference.

This will reduce heating effects on the motor/battery/esc since less current is pulled by the motor, due to the smaller prop.

And, going to the opposite direction, adding an inch in diameter to an existing prop can lead to motor/esc/battery overheating, depending on how close to their respective limits your motor was to begin with.

One reason an on line ammeter such as an Astroflight Wattmeter is so useful. These meters can directly measure the amperes, volts, and watts pulled by your motor/esc/battery setup.

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