Top Flite Giant Scale P-51d ARF converted to Neu2215/1.5y

[LaxLife]

We picked up this beautifully detailed airframe last year and set about converting it to electric. After lots of debate, research and testing we landed on this setup:
Motor: Neu2215/1.5y geared inrunner www.neumotors.com
ESC: JetiSpin200
Battery: 2, ThunderPower Extreme 6s (22 volt) 9000 mAh packs in series to create a 12s, 9000 mAh power source
Wiring and connectors were 13 gauge silicon noodle wire with 5.5mm bullet connectors including a fabricated safety shunt placed under the fuselage at the forward end of the wingroot
Prop? we really wanted a 4 bladed scale prop to match the high quality detailing the original builder gave to the airframe. We found a British Columbia firm called NRG Research and their Solo Props!
www.soloprops.com
We installed a 24" scale version and Tru-Turn cut a beautiful spinner to match it.
Here is a video of the maiden flight:
http://media.putfile.com/TopFlite-GS-P51d-Electric-Neu2215-12s-24--SoloProp

and here are some pictures:

http://img2.putfile.com/thumb/9/24318145584.jpg (http://www.putfile.com/pic.php?img=6477513)

http://img2.putfile.com/thumb/9/24318145572.jpg (http://www.putfile.com/pic.php?img=6477512)

http://img2.putfile.com/thumb/9/24318145530.jpg (http://www.putfile.com/pic.php?img=6477511)

http://img2.putfile.com/thumb/9/24318145581.jpg (http://www.putfile.com/pic.php?img=6477510)

http://img2.putfile.com/thumb/9/24318145437.jpg (http://www.putfile.com/pic.php?img=6477507)

http://img2.putfile.com/thumb/9/24311542680.jpg (http://www.putfile.com/pic.php?img=6475839)

[jonnyjetprop]

Sweet plane :D

John

[megawatt]

WOW! :eek: Nice conversion.
Makes me wish I had not sold my Top Flite Giant scale mustang kit. :( With todays motors/batteries, seems almost anthing can be converted.Too cool.

What is your AUW, and WOT current on this model?

Jeff

[LaxLife]

All up weight: 25 lbs
current? I haven't measured it yet (poor answer but that's the truth--I was too scared and I wasn't the test pilot, just the financier!)

[hul]

nice. How much pitch are you running?

Hans

[davidleitch]

I don't know much about planes that heavy, but seems like a really well built undercarriage to survive a landing like that. Surely you are supposed to come in a bit lower with a little power on.

Looks like a great plane and the Neu motor seems to do the job

[countrygentleman]

Can you show me a little bit more on how you placed the batteries and how you were connected/disconnecting?

[LaxLife]

Pitch setting? The Solo Props have an ingenious variable pitch hub. We ran this maiden on 10 degrees. Now its time to tweek the prop and tune it to the motor. I'm ordering 22" and 20" blades to test them since the 24" blades provided so much power. My test pilot's school beckoned him to return so we had to get it in the air without some of the usual monitoring and tweeking one would normally pursue. Our maiden was more of a "light this candle and see if she flies" moment.
Landing? yes it was too hard but the robart springs cushioned it nicely and there was no damage. Chalk it up to maiden flight jitters. The retractable tail wheel collapsed on the 2nd or third bump: no air pressure. We had discovered a mystery air leak on taxi out and decided to keep the gear extended the entire flight. The tail's retainer isn't firm enough to keep it extended when there is no air pressure.

Battery placement?
The two BIG ThunderPower 6s 9000 mAh Extreme Series lipos lie next to each other in the middle of the wing root battery tray. We had thought they'd be going much further forward up under the cowl but balancing tests proved she was nose heavy so we extended the tray aft by moving the retract servo and valve even further aft which wrecked TopFlite's nicely laid out retract valve/servo station but so be it. Before the next flight I'll post images of the tray with the packs installed in their flight position.

http://img2.putfile.com/thumb/9/24411564480.jpg (http://www.putfile.com/pic.php?img=6482780)

Wiring?
here is a shot of the main battery connection just below the safety shunt. We used 13 gauge silicon noodle wire and 5.5 mm bullet connectors. The lipo's have male positive connections and female negative connections. To create the serial connection; one pack's positive connects to the other pack's negative and then the free connection from each pack makes the connection at the plane shown here to the left, just below the safety shunt. I haven't conected the JetiSpin200's third "anti-spark" line yet but its on the preflight list for this week. I did get a good spark when arming the shunt but its not so bad when you know its coming.
http://img2.putfile.com/thumb/9/24411564432.jpg (http://www.putfile.com/pic.php?img=6482781)


Safety Shunt Detail-John, aka ESB-help taught me how to rig safety shunts to provide a positive method of cutting off power to the prop in pre-post flight. Now all our planes have them and its a great source of peace of mind knowing that the lipos are cut off completely. Here are some shots of the safety we installed on the TF P-51 which sits under the fuselage at the fore of the wing root.
http://img2.putfile.com/thumb/9/24411564430.jpg

http://img2.putfile.com/thumb/9/24411564417.jpg (http://www.putfile.com/pic.php?img=6482782)

[davidleitch]

Very nice safety shunt. Will use that myself.

[megawatt]

Very nice safety shunt. Will use that myself.

Ditto that, I don't like relying on the radio (Rx) switch with these Kilowatt power systems.Never had a problem, I just don't trust it.

Jeff

[LaxLife]

I started using these Maxx Products safety shunts;
http://www.maxxprod.com/mpi/mpi-21.html#Harness
and they brought real peace of mind knowing that the lipos were totally cut off from the prop and other drains of their precious voltage. For rigs above 8s I really prefer to have 13 gauge silicon wire and 5.5mm bullet connectors so I had to make the shunt myself. Its not pretty but it works. BTW a great source of cheap shrink tubing in all sizes is on eBay;
http://stores.ebay.com/Heat-Shrink-Tubing

[Sture Smidt]

This is mine. Axi 5330/18 with 10 LiPo in seres.

Sture

[hul]

Pitch setting? We ran this maiden on 10 degrees.
at the tips, I assume? That would be about 13.3" pitch. My calcs give between 5 and 7kW depending on how well the pack holds volts. No wonder you have plenty of power....

Hans

[LaxLife]

Sture Smidt, nice plane thanks for joining in. What kind of prop and what does it produce Amps, Watts? How long are you able to fly? What is your AUW? What ESC are you using?

hul, I'd love to know more about your calculations (MotoCalc?) what kind of watts, amps do you think this produces? (silly question I know since I have the plane, I should just go measure it but I love the idea that somebody actually understands the math!) What kind of flight time? The packs are ThunderPower Extreme series 6s 9000 mAh. I hook 2 in series for 12s, 9000 mAh. After that 4 minute maiden flight I replaced 2000 mAh to each pack upon recharge. Preflight voltage was 25.2 per pack and 23v after the flight. And where are you in Switzerland? We have some family in Wintertur and Lugano.

[Sture Smidt]

10S 3700 mAh 6 minutes flying time (will buy 5000mAh packs soon)
8.5kg
200km/h (measured)
18x12 APC-E
Robart retracts

Sture

[hul]

hul, I'd love to know more about your calculations (MotoCalc?) what kind of watts, amps do you think this produces? (silly question I know since I have the plane, I should just go measure it but I love the idea that somebody actually understands the math!) What kind of flight time? The packs are ThunderPower Extreme series 6s 9000 mAh. I hook 2 in series for 12s, 9000 mAh. After that 4 minute maiden flight I replaced 2000 mAh to each pack upon recharge. Preflight voltage was 25.2 per pack and 23v after the flight. And where are you in Switzerland? We have some family in Wintertur and Lugano.
it's an Excel sheet that uses the same math as Motocalc (there's series of articles on the ezone that has the math in it). It doesn't model battery performance, voltage under load is an input. And it's all a bit rough and depends a lot on prop characteristics.
I get about 160A at 40V, about 180A at 42V and a pitch speed of 60 to 65mph. 2000mAh in 4 minutes is only 30A though, a rather large difference. Don't think you should rely on my numbers....
I live about 1/2 hour west of Winterthur in a small town near Zurzach.

Hans

[LaxLife]

Sture, I'm impressed with your 8.5 kg (18 lbs) weight! Very light especially with Robart retracts!

hul,
Thanks, I hope I'm not running 160 amps, that's too much! Even the idea that I could possibly do that has got me running to order 20" blades for the SoloProp. I don't need the power of my 24", 4 bladed prop and I'd like to go easy on my ESC and lipo's. Your icon is a DH Mosquito, is that what you fly? I've got an old Aerotech International fuselage in my shop that's is dying for a conversion but I can't find any information on it and the UK firm that made them is long out of business. Do you know this kit? 80" wingspan approximately.

[countrygentleman]

The thought of everyone having a P-51 doesn't bug me, but why are they all Big Beautiful Doll? Mix it up a little.

[hul]

Your icon is a DH Mosquito, is that what you fly?
used to fly. It was only small, 43".

My calculated amp draw could easily be off by 30%. 100A would still be plenty of power...

Hans

[LaxLife]

hul,
thanks for the calc. Steve Neu just wrote to say that voltage is not an issue there's no practical max. but the amps shouldn't top 160 for more than a second or two. I gotta de-prop a bit, drop from 24" to 20 or 22.

[Sture Smidt]

Hi,

Look here for pictures http://www.rcgroups.com/forums/showthread.php?t=568603

SS

[hul]

gotta de-prop a bit, drop from 24" to 20 or 22.
I would measure first, the calcs aren't that reliable

Hans

[LaxLife]

Sture that's a nice build and conversion. I wish I had known of your thread last year.

[rosek007]

I just got mine done today,
axi 5345/14, zinger 4 blade prop,cchv110 and 10s extreme tp.
It's going to fly with the stock landing gear because tower is out untill the end of the month so...
KEVIN

[Synwpn]

hahah i should have known Kevin would end up with one.

I've got one about ready to start. It's been stripped of the covering and I need to sand down the paintjob on the cowl. Have yet to decide which paint scheme to go with.

I've got Sierra Precision retracts for it and am starting to think about motors. Leaning toward the Hacker A100, but will look at Neu motors.

[rosek007]

Dave,
I had to, been thinking of this thing for a long time now. Only bad part is tower is out of the retracts so i had to maiden it with those god awefull "afterthought" stock landing gear. Flys oh so sweet though.
When the flaps come... :D :D :D :D :D :D :D
Kevin

[Synwpn]

Kevin, what can I say,

heh. And I've got a Robart for the rear wheel retraction.

I am totally sold on this stuff with the variable rate valves. On my Hellcat, watching the gear go up is enough to distract me from flying it!

[rosek007]

Those look nice, if tower don't get it in soon i'll have to get a set, for now i'm flying my boomerang xL...now that flys nice...oh and my yellow f15 is almost done.
Kevin

[rosek007]

I put 4 more flights on mine today, I have to tell you it flies great but it definately needs the retracts, I guess I wont fly it again untill i get a set.
kevin

[LaxLife]

I finally got around to some max power static testing today:
4200 Watts
108 Amps
24" 4 bladed SoloProp
12s, 9000 mAh ThunderPower Extreme lipos (2, 6s 9000 mAh in series
Jeti Spin 200 ESC

[Jocke]

Can you setup the pole count and gear tru the Jeti BOX and see what your rmp is?

[LaxLife]

Jocke,
Good morning!
I'm not sure what rmp is but I do believe the Jeti Spin programming box allows me to enter the number of poles and the gear ratio. I was going to reprogram the ESC because I'm not getting a smooth throttle acceleration. It "jumps" on when I first give it throttle, as if the brake is set but I'm I did not set the brake. Perhaps I set it at soft brake. So I'm gettnig out the programmer anyway and I can check the rmp. Can you explain what rmp is?

[Jocke]

Hehe... my fualt.. i have no idea what RMP is... but i would like to know the RPM :)

[LaxLife]

I didn't realize the Spin Box could tell me the RPM. I'll check it. I did a check earlier using a tachometer and it was about 4500 RPM

[Fool]

I just got mine done today,
axi 5345/14, zinger 4 blade prop,cchv110 and 10s extreme tp.
It's going to fly with the stock landing gear because tower is out untill the end of the month so...
KEVIN


Kevin,
What size zinger prop, amps and rpm? I'm going to do a p47 with similar motor and battery.

Jim H