Motors Need help finding motor

[Derek]

It has been suggested to me to get an O.S. .25 Brushless Motor 3820-1200kv for my new flying wing. However, that motor is $75.00. That's a bit pricey for me for just a motor. Maybe I'm "cheap"...I dunno. Ok...yes....I'm "cheap"!!

I'm hoping that the helpful people of RC-Help.com wouldn't mind helping me to find a motor that is similar but with a "lesser" price tag.

Here are some specs for the O.S. motor:

FEATURES: For .20 - .25 size airplanes Stainless steel prop shaft Rigid rear mounting design Centrifugal fan design with angled ventilation holes draws air through the motor and across the windings and magnets for improved cooling

INCLUDES: .25 Brushless Electric Motor with Backplate, four Phillips Head Mounting Screws, 3mm Gold Plated Male Plugs attached to leads, three 3mm Female Plugs with Shrink Wrap, Prop Adapter and Instruction Sheet

REQUIRES: 60A brushless ESC

SPECS:
Rated Power: 440W
Rated Voltage: 11.1 - 14.8V
Rated Current: 30 - 40A
Maximum Current (10 sec): 75A
No Load Current: 1.9A
Phase Resistance: 21.4 miliohms
Maximum Efficiency: 85%
kV: 1200
Poles: 14
Shaft Diameter: 0.20" (5mm)
Shaft Length: 0.45" (11.5mm)
Weight: 5.46oz (155g)
Lead Wire Length: 3.5" (90mm)
Length of Motor Can: 1.7" (43.3mm)
Diameter of Motor Can: 1.47" (37.5mm)
Length/rear of Motor Can to Prop Washer: 2.3" (58mm)
Prop Washer Diameter: 0.87" (22mm)
Thickness of Motor Mount: 0.12" (3mm)
Width of Motor Mount: 1.96" (50mm)
Height of Motor Mount: 1.96" (50mm)

Performance for this motor with different props and LiPo cells is as follows (all data with 60A ESC):

Prop Size Max Electric Current LiPo Cells
9.5 x 7.5 34A 3S
9.5 x 8 35A 3S
9 x 6 48A 4S
10 x 6 37A 3S
10 x 7 42A 3S
11 x 7 50A 3S
12 x 6E 48A 3S

....or....is this just a really good motor and I should just work a bit of overtime and get this O.S. motor???

Thanks in advance!!!

 

[Lee]

This one seems pretty close to the specs of the one you're looking at.
Turnigy Aerodrive SK3 - 3542-1250kv Brushless Outrunner Motor

 

[Derek]

Thanks for finding that, Lee! I must have overlooked the SK3 motors because I don't even remember seeing this one.

 

[Tony]

Derek, those OS brushless motors are MONSTERS for power. There is not a clone/cheap motor out there that will touch the power of those motor. OS, Reedy and the like are the top of the line when it comes to brushless motors. If you get it, you will LOVE it.

 

[Derek]

Thanks for the comment, Tony!

I did order this motor:

Turnigy D3548/4 1100KV Brushless Outrunner Motor (USA Warehouse)

...and a 60amp Plush ESC..along with a few other things. I'm gonna try out this motor and see what happens. With all the overtime that I plan on working, over the next few weeks, if I dont like it...I'll just order the OS motor that I described above. I'm planning on putting this motor on my 49" flying wing. I love flying wings. However, I don't want the wing to just "fly"....I want it to "perform"....and eventually become my FPV platform.

 

[Lee]

Ed at Experimental airlines just did a review on this motor and ESC combo, that seems to match your specs too.
TURNIGY NTM 35-36A 1400KV POWERPLANT TESTING - "The Powerhouse" - YouTube

 

[Tasajara]

One question, what flying wing are you putting this motor on?
I have built 7 different wings running from 3s to 6s LiPo's and one 5s A123 setup. My wings ranged in size from 40", 52" and 60" wide.
Kv of my motors were 2800,2200,2100 also 3300, 1000 and 950KV

I had one of my larger wings running on 4s with a Power Up 15 Sport Outrunner Brushless Motor 1000Kv with a 9x6 Aeronaut Cam prop.
As far as size it would be a 35-40mm 4.5 oz (128 grams) motor.
You get around 3.5lbs thrust at 32 to 35 amps give or take.
The price is pretty good to....$25.99

I also ran this motor on my SkyWalker 4s 5000mAh 9x6 and flew for 28 min at half throttle or less. If I had done some gliding could have went longer.

 

[Derek]

I'm building this wing:
This wing has the KFm4 design. I have been watching FPVTrond's flight videos for several months. It didn't take my long to decide that I wanted one. So, I built one. Although my wing came out to be a bit heavier than his, about 4oz heavier, it should do real well.

here is the motor that I have on the wing right now:

Turnigy D3548/4 1100KV Brushless Outrunner Motor (USA Warehouse)

I spoke with FPVTrond and he said that this Turnigy motor will work but it won't perform as well as the OS motor that he's using. I have a 10x7 APC prop on this wing and I'd like to use a folding prop but I have to wait for the aluminum hub to come in. I was also hoping to maiden my wing today but it started to rain...again.

Judging from your post, above, it sounds like you have quite a bit of experience with Flying Wings. I'll be starting a new thread, specifically for my wing, and we can discuss details further there about the wing. I don't want Tony getting upset with me for having multiple topics in one thread, lol. Well...I just don't want Tony getting upset at all. I've learned a lot from him, so I wanna stay on his "good side" lol.

 

[Tasajara]

Cool I will check it out...

Here are a few I have built, epp and bluecore foam.

 

[Derek]

WOW!! Those are really really nice! Thanks for sharing the pics!

- - - Updated - - -

Curiosity has struck me again.

Here is the motor that I've chosen for my 49" flying wing:

Turnigy D3548/4 1100KV Brushless Outrunner Motor


Spec.
Battery: 3~5 Cell /11.1~18.5V
RPM: 1100kv
Max current: 50A
No load current: 3.1A
Max power: 910W
Internal resistance: 0.023 ohm
Weight: 159g (including connectors)
Diameter of shaft: 5mm
Dimensions: 35x48m
Max thrust: 2150g

Is this saying that I'll get 910 watts when using the 5S? Sounds to me that I need to hook up my little 2-in-1 meter again. I'm intending on running this wing with a 3S setup. hmmmm!

 

[Tasajara]

It is just stating the max wattage the motor can handle.
I would run it in the 40amp range to be safe. But it being in open air you should be fine with a little higher when you are testing static amps.
The prop will unload some in the air and pull less than static amps measured.
To get close to 900 watts you would have to be pulling over 70amps on 3s witch is over the rated amps of 50.
So more realistic wattage on 3s would be more like 500 watts and pull around 40 amps WOT.
Normal flight needs about 100 watts per pound. 3D flight would be around 150 watts per pound.

 

[Derek]

Hmmm, ok. You say that you would run it in the 40amp range to be safe. How would I know how to get it in that 40amp range?

Like I mentioned above, I guess I just need to hook up my watt tester to the wing and see what I get.

The mentioned "40amp range" would be awesome because I have a 60amp ESC and a 10amp CC BEC on this wing. I surely don't need to have it "screaming" across my flying field and overload the ESC and then smack into the ground at 50+ mph, lol.