ddemu

Hi guys.

I'm looking for suggestions/recommendations for e-power systems to convert my 7.5-pound Great Planes F-14.
It currently has a top speed of @115mph with a SuperTigre .75 and a APC 12x6 prop.
I'm at 4800 feet above sea level and I want to limit prop size to 14-inches for ground clearance.

Top speed isn't all that important, but it is fun to fly and a show-stopper when flown at demonstrations
The plane gets "tricky" at slow speeds so equal or a slight increase in power is more acceptable than much of a decrease.

From what research I've done so far (and if I'm understanding it correctly) I need a high Kv (rpm) motor to spin the smaller props that what many warbirds (taildragers) use. I want to get this right as I won't have a great ability to change motors for some time if it's not.

Give me your best suggestions for a good motor and battery set up!

jetrichie

at 7.5 lbs will need a motor putting out about 800w to get any sort of performance, high Kv motors wont really suit as prop will be too small, as an example normally a 2200kv motor will suit a 6x4. Look a motor wattage for a given prop size, to get any sort of performance you are going to be looking at 60A plus, if it was me I would want about 1000w.

tIANci

Okay ... plane is about 7.5 lbs, you want to go 5S or 6S? You can look into the following as a baseline to start with:

Motor - China made 4260 sized motor of no more than about 600 KV (DualSky 4260-6, AXI 4120-18, Hyperion 4025-10, Hacker A50-10S, Scorpion 4020-12)
Batt - 6S 3,300 to 3,700
ESC - 80A
Prop - 10x10 to 12x10 to 13x10

You ought to be pulling about 1,200W or more.

jetrichie

I forgot to ask, WHY?? electric'a are really for foam planes and park flyers, this prop jet needs noise

tIANci

Can someone please ban this slimy guy? Hahahahaahahahahaa ... Richie, we can always add a sound module! Scale sounds!! Hehehehehee ...

tIANci

.

jetrichie

Yes sound system is the way to go, but bigger models need plenty of noise and smoke

ddemu

We're considering an electric conversion for the conveinience and to improve motor reliability.

Cost will be the big decision maker as it appears I can replace the problematic Super Tigre .75 with an O.S. engine cheaper than going electric.

But a big, fast electric, with it's own whine of noise seems pretty cool too - and it would improve the looks of the plane by not having the engine and muffle hanging out the side. In flight the propeller disappears and all you would see is the sleek lines of a cowled in motor. The electric whine of the motor would be "sport-scale" for the plane too.

There's no way I'll ever afford a turbine, and our field won't handle one anyway. This plane can't be converted to an electric ducted fan so a electric prop job conversion would be the next best thing. It's one of those planes that's just too cool to give up on, but needs something better to keep from crashing due to flame out problems.

Thanks for the replies received so far.

Aircraftfreak15

how heavy is the plane?

tIANci

Smoke? Don't worry, we can always FRY the ESC and you see smoke, then you will hear a lot of noise from the pilot and caller too! Hahahahaa ...

jetrichie

I had one for years with a SC61 and it never missed a beat, put the right engine in it and you will be much happier

tIANci

Stop meddling with our new convert!!!

ddemu

We went with the Scorpion 4020-12 motor, a 100amp ESC, and two 4,000mAh 11.1 batteries = 22.2 volts.

Test flights have been with a 12x8 APC electric prop (I broke the 12x10 on a botched take-off). Test flights have been limited to 5-6 minutes (not wanting to push things too much) and have been hampered with some other issues (retract problems, bad switch and then a bad elevator servo).

It's still fast, no smoke (yet[X(]) but it sounds COOL as it's more jet-like than the 2-cysle glow engine was.

House construction has limited flying / testing time. But the fun continues! Thanks for all the suggestions and help.