The motor on my son's Fledgling(gen II, brushless) has gone out again. It uses a cheapo from HobbyKing. It's a 3015-7 and below are the listed specs from HobbyKing website.
http://www.hobbycity.com/hobbycity/s..._1000kv_/_470W

Model: TowerPro 3015-7
Size: 37.2*60.3
Weight: 133g
Voltage: 10v
Idle Current: 2.2A
Suggested Battery Config: 3-4Lipo
Kv: 1000RPM/v
Shaft: 5mm
Max Eff Current: 30A
Max current: 40A
Max Power: 470W
Suggested prop: 10*5, 11*5

I bought this KMS 2814/06 motor from Hobbypeople and then found out the shaft size is different so i can't use the prop adapter.

KMS Quantum 2814/06 outrunner Ref: M-KMSQ2814/06
Max. Continuous Current (Amps): 24
NiCad/Ni-MH: 7-10 cells
LiPo: 2-4 cells
I0: 2A
Turns: 6T
KV RPM: 1290
Diameter: 35mm
Max Current: 32A/60s
Propeller Range: 9.5 x 5, 9 x 6, 10 x 4.7, 10 x 5, 10 x 6
Resistance: 45 mohm
Bearings:
pole: 14
ESC Timing Degrees: 20-30 (high)
Weight: 103g
Length: 36mm
Max Efficiency: 80%
Shaft dia: 4.00mm


Is this motor a good replacement? Is there a prop adapter to use on the long shaft?


skeeter

Hmmm.. what's odd is that most, if not all, of the brushless motors I've bought have come with a prop adapter. There must be a suitable replacement that is reasonably priced that has a prop adapter.

Did you check Tower and Rimfire motors, for instance?

CGr.

Both the Rimfire or Tower motors don't seem to include a collet type adapter which is what the original engine has. The engine mounts against the backside of the firewall, so how can i make this work? Should i buy a different engine? If so what?

skeeter

The shaft size of 5MM sounds quite large for these smaller planes. Mist have shafts from 2.5 to 3 MM. Can you measuer it"  3.5MM is 1/8".  Also does it have a long shaft that the prop mounts in or just a short on near an inch long.

I found many of these have the same mounting. Also, is your motor body turning which is an outrunner or does the body mount to the bracket and just the shaft turn which is an inrunner.

Does the ESC which is the little flat thing between the motor and the battery that the wires come on go from say what amperage like 15A or 20A etc.  Before you can search for a motor you need to know more on what you are looking for. How large in diameter is the propeller? 

Sorry for these basic questions but they will help your search. Most motors I have ordered come ship from Asia and take a moth to get here. I just got my last one yesterday that I ordered from Hobby King in early January.

Several places like Radical stock quite a few. ask Dave at  Radical R C <[email protected]>. He is most helpful on things like this and has a good inventory too.

I hope this gets you on the right track and your son back in the air.

CG retired, I just had an idea that maybe it's the shaft adaptor that's 5MM. I have a few of those with that diameter that the bore size of the prop is 5MM. The motor shaft is only 2.5MM.. I have never seen a small motor with the 5mm shaft. Especially on these smaller planes. I have one little plane with the motor shaft that's shaft is only 1.5MM It's really tiny.

Buying the right motor is a real learning process.

You got that right. Electric is very different from Glow in more ways than one.

CGr.

As the spec's for the HobbyKing motor say, it is 5mm. I measured it. The oringinal chinese motor is an outrunner and the shaft only sticks out about 1 inch and uses a collet-type prop adapter. I'm using a 10x5 prop The new KMS motor i have, has a 4mm shaft. I measured it. And is also an outrunner and the shaft on the new motor about an inch long also. The ESC (little flat thingy) has no markings on it what so ever, however the spec's above for the original chinese motor show a max 40 amps so i believe it should be something at least 40amp if not a little higher. The fledgling is not really a small plane but it is not a big one either. 50"ish wingspan.

The prop adapter that comes with the new KMS motor bolts to the back of the motor and has a nut to hold onto the prop. Unlike the collet style the old chinese motor has.

I would like to buy a motor locally that will fit correctly without alot of trouble, but also not costing an arm and a leg. The people at the LHS really don't know jack about the electric motors to be able to point me to the right one.

skeeter

How close is the replacement motor mountingto the old motor mechanicallyif you match it electrically? What is the bore size of the prop you have. Sorry about the questions but prop adaptors may be easier to locatethanfinding the motor with the right shaft dia. I looked at the motor you referred to earlier. Is thismotor exact kindyou need to replace ? I'll look for you also if I understand the specifics.

Did the old motor burn out or just fail. If you use you nose you can tell if it's burned generally.

I spent my whole carreer in the electric motor industry albiet larger than these model motors but motor basics apply up and down the size ranges.

I hope I can help you so I'll be watching for your answers.

AltaTed

Take a look at the motors here http://www.radicalrc.com/category/Himax-Outrunners-114. Just about 2/3 of the way down the page the motor the Himax3516 model should be close to your wishes.

AltaTed

The first motor spec's i listed is exactly what i have in it now. The motor has given me nothing but trouble loose magnets, weird noise, low power. The bolt up for the new motor is not exactly the same but i could make it work if the shaft size wasn't a problem. After looking at countless engines, kv, watts, amps, and reading on brushless motor ratings i'm starting to think this KMS engine is less power than the chinse one i have. I found another KMS engine that might just fit the bill. It"s the KMS2820/06 listed here.

http://www.hobbypeople.net/index.php...ess-motor.html

It has almost the same spec's as the Chinese one and even a 5mm shaft so i should be able to use the prop adapter i have. I just hope Hobbypeople has it in stock here.

I don't believe the himax motor recommended would work because it seems to be larger around and i don't much room to spare in that area.

skeeter

I ordered some colets of varying sizes from Hobby King to solve similar problems. They are very inexpensive, just search "colet" and they come up.
Good Luck

I don't know the brands of e motors sold throughout the hobby distributors world but noted almost all are made in China. Countless brands...I can't reccomend any brand name and have no favorites,, nor am I able to say one is better than another.

I looked at the one you mentioned and know nothing about it.  It looks nice but then again they all look nice and every one I have seems to be made well concidering it's size.

I wish I could say more on these but, if it were something I was doing I would put in the largest motor you can fit into the plane.  You can always throttle back but burning out motors is telling you something may not be sized correctly.  Did you look at the other similar HiMax motoer Radical offers. I'm looking only at similar motors to your needs, not recommending a specific product.

Good luck on this project.