Great Planes Rimfire 63-62-250 Out-Runner Brushless Motor Questions...

[Chadworkz]

I know that some of you run these BL Outrunners in your crawlers, so I thought I would see what you thought about this one...it's a 250kV motor, so it should be nice and slow, and super torquey! What is needed to mount an outrunner and the pinion?

Here is the link [Great Planes 250kV BL Outrunner]

Here are the specs:
Can Diameter: 2.48" (63mm)
Can Length: 2.44" (62mm)
Shaft Diameter: .32" (8mm)
Shaft Length: .98" (25mm)
RPM/V (kV Rating): 250
Input Voltage: 29.6-37.0V
Max. Constant Current: 45A
Max. Surge Current: 72A
Max. Constant Watts: 1665W
No Load Current: 1.5A
Weight: 22.4oz (635g)

[Chadworkz]

How about out-runners in general?

[EeePee]

Originally Posted by Chadworkz

How about out-runners in general?

Old news. Lots to read.

In brief, chirp chirp, spin, chirp, burp, chiiiiirp, spin.

[JohnRobHolmes]

I hope you plan to run 12s so you can get some wheelspeed!

[Ripperfi]

Originally Posted by JohnRobHolmes

I hope you plan to run 12s so you can get some wheelspeed!

Holy !! They make 12s ??

[JohnRobHolmes]

two 6s packs in series would do the trick. Too bad there isn't an ESC with crawling software available to use with 12s.

[EeePee]

8 mm shaft. Ha!

[Chadworkz]

Haha, damn! Thanks, I was just curious...I love my FX-R & 55T!!!

[Espeefan]

Wow, that motor would be serious overkill for a crawler. An 8mm shaft is not very practical for putting the common sized pinions on. You would have to either turn the shaft down to a more standard size, or bore the pinions out to fit. Not that you would ever run a 9 tooth pinion, or smaller, with a 250 KV motor, but I cannot see it being possible to even bore a 12 tooth pinion out, and have much material left for the set screw to thread into, unless the pinion was a custom design with a larger diameter shoulder.

The other problem you'll have is just mounting the motor to the tranny or gearcase. It looks decieving, but that is a huge outrunner. It could fit, maybe, but it could have some problems in a tight area, like a Clod gearcase, or maybe in the smaller tube chassis trucks with shaft drives. You would definitely need an adapter plate to mount the motor. Such plates do exist, but then because this Rimfire motor is so large, it's bolt pattern is spread wider then most plates available. I believe the measured distance hole to hole, on center is 25mm, in order to fit to the adpater plates available. No doubt that motor has a different bolt pattern.

To be safe, you'd also need a fairly good ESC to run it and meet the amperage ratings. Not that you'd ever hit the max 72 amp rating in a crawler, but if you did, your ESC better be able to handle it.

Last of all, if you had a problem with throttle control, when a tire gets bound up, expect some breakage! 1665 watts of power is approaching 1.75 hp, plus! 745.XX watts equals 1 horse.

On another note, I'm running two Rimfire outrunners on my Clod. They are smaller, but seem to be overkill as well. I do know they are pretty darn torquey. I can physically hang onto the motor cans with my hands and with a little bit of throttle added, they start nice and smooth and feel unstoppable!

[Chadworkz]

Damn, that's a bad-ass Clod!!! Thanks for the info!

[BJoe]

What Rimfires are those Espeefan?

[Espeefan]

Originally Posted by BJoe

What Rimfires are those Espeefan?

They are the 35-48-850KV motors. 35mm diameter can - 48mm long - and 850KV rating. Even these are overkill for a crawler, but I choose them because they were readily available, I could make them fit reasonably well on my crawler, and because I knew they'd have gobs and gobs of torque. You'll need a better then average ESC to run them. They can draw as much as 72 amps, full load, so your typical 30 amp ESCs will not be a good match with these things.

[BJoe]

Originally Posted by Espeefan

They are the 35-48-850KV motors. 35mm diameter can - 48mm long - and 850KV rating. Even these are overkill for a crawler, but I choose them because they were readily available, I could make them fit reasonably well on my crawler, and because I knew they'd have gobs and gobs of torque. You'll need a better then average ESC to run them. They can draw as much as 72 amps, full load, so your typical 30 amp ESCs will not be a good match with these things.

Thanks, what kind of opinion shaft and motor mount hole spacing do they use? I'd probably put one on my Wheely King once the Super Rooster dies.

[zoojunkie]

250kv is a bit too slow for a crawler, you won't have any wheel speed unless you use 12s like JRH said.

I recommend you find a 28mm-38mm BL outrunner motor with about 1050-1300kv running 3s.

I'm running a 35mm 1250kv outrunner motor and it's overkill as is in my AX10. Anything larger and you won't have decent slow speed control because of the magnetic force you'll have to break is larger in larger motors. Plus you won't have drag brakes as well. I had to turn off my drag brake on my ESC because I couldn't even break the magnetic force in my motor!

[Espeefan]

Originally Posted by BJoe

Thanks, what kind of opinion shaft and motor mount hole spacing do they use? I'd probably put one on my Wheely King once the Super Rooster dies.

It's a 4mm shaft, which is in between the standard 3mm and more common 5mm brushless shafts. More common 32P 5mm pinions are available, but not any 4mm ones. I bored out a 3mm pinion to fit.

The bolt pattern is odd, compared to typical 540/550 motors too. It's a cross shaped pattern, with 25mm of distance between the holes. It will not not bolt up without some sort of adpater. Holmes Hobbies used to have an adapter. I made my own, by modifying an adjustable motor mount for the Clodbuster.

I would suggest you go with a smaller motor then mine. Maybe for a super class crawler, my motor would fit, but on an AX10, you'll probably have trouble fitting it right. Space is tight. Also, I am sure you would be breaking a lot parts. The motor I have will probably have enough power to tear up my Clod gearcases too. On an AX10, I think you'd break even more.

Check out my thread, to see more pics of the motor and adapter plates.

Building the Hustler

[Espeefan]

Originally Posted by zoojunkie

250kv is a bit too slow for a crawler, you won't have any wheel speed unless you use 12s like JRH said.

I recommend you find a 28mm-38mm BL outrunner motor with about 1050-1300kv running 3s.

I'm running a 35mm 1250kv outrunner motor and it's overkill as is in my AX10. Anything larger and you won't have decent slow speed control because of the magnetic force you'll have to break is larger in larger motors. Plus you won't have drag brakes as well. I had to turn off my drag brake on my ESC because I couldn't even break the magnetic force in my motor!

I agree. 250KV is way to slow. My 850KV motors seem slow too, but once I start driving the truck, then I'll really know. I'm running 8 cells, so I could bump the voltage up to get more wheel speed, but most likely I will go up a couple teeth on my pinions. The motors have so much power they won't even notice. Try to find a brushless motor that is happy on 6 to 12 cells. 7.2 to 14.4 volts. That way you have options.

Likewise, I have a drag brake turned on to the max my ESCs allow, but to be honest, I don't really need it. The motors will hold the truck on a 45 degree slope (or there abouts) without any power even going to them. The magnets are really strong.